Sqlite for delphi

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SQLite
SQLite，是一款轻型的数据库，是遵守ACID的关系型数据库管理系统，它包含在一个相对小的C库中。它是D.RichardHipp建立的公有领域项目。它的设计目标是嵌入式的，而且目前已经在很多嵌入式产品中使用了它，它占用资源非常的低，在嵌入式设备中，可能只需要几百K的内存就够了。它能够支持Windows/Linux/Unix等等主流的操作系统，同时能够跟很多程序语言相结合，比如 Tcl、C#、PHP、Java等，还有ODBC接口，同样比起Mysql、PostgreSQL这两款开源的世界著名数据库管理系统来讲，它的处理速度比他们都快。SQLite第一个Alpha版本诞生于2000年5月。 至2015年已经有15个年头，SQLite也迎来了一个版本 SQLite 3已经发布。

工作原理

不像常见的客户-服务器范例，SQLite引擎不是个程序与之通信的独立进程，而是连接到程序中成为它的一个主要部分。所以主要的通信协议是在编程语言内的直接API调用。这在消耗总量、延迟时间和整体简单性上有积极的作用。整个数据库(定义、表、索引和数据本身)都在宿主主机上存储在一个单一的文件中。它的简单的设计是通过在开始一个事务的时候锁定整个数据文件而完成的。
SQLite的一些基本操作跟SQL很类似，基本上有SQL基础的都能看明白。

SQLite的图像查看工具有很多，比如SQLiteSpy、SQLiteBrowser、SQLiteStudio等。

SQLite默认是utf8编码，使用pragma encoding可以看出数据库的编码。

建立数据库后，可以直接输入“pragma encoding = UTF8/UTF16”来改变编码，但数据库有了数据以后，编码是不可以修改的。

SQLite的源码可以http://www.sqlite.org获得。关于SQLite的更进一步的语法和信息，请参http://www.sqlite.com.cn/http://www.sqlitecn.org。

delphi中使用sqlite3
这里有一个delphi中使用sqlite3的demo：A simple Delphi wrapper for Sqlite 3 | Tim Anderson's IT Writing

这个demo中包含了sqlite3.pas，sqlite3table.pas，sqlite.dll三个文件，里面包含了操作sqlite3的源代码，利用这三个文件，就不需要第三方组件了

添加步骤：
将simple sqlite 3.0 for delphi 中的 sqlite3.pas，sqlite3table.pas拷贝至工程所在的文件夹。并在工程中添加这两个个文件。
拷贝 sqlite.dll到编译生成exe文件的文件夹。这个根据个人的设定。

Sqlite3.pas 源码：

unit SQLite3;

{

Simplified interface for SQLite.

Updated for Sqlite 3 by Tim Anderson (tim@itwriting.com)

Note: NOT COMPLETE for version 3, just minimal functionality

Adapted from file created by Pablo Pissanetzky (pablo@myhtpc.net)

which was based on SQLite.pas by Ben Hochstrasser (bhoc@surfeu.ch)

}

{$IFDEF FPC}

{$MODE DELPHI}

{$H+} (* use AnsiString *)

{$PACKENUM 4} (* use 4-byte enums *)

{$PACKRECORDS C} (* C/C+±compatible record packing *)

{$ELSE}

{$MINENUMSIZE 4} (* use 4-byte enums *)

{$ENDIF}

interface

const

{$IF Defined(MSWINDOWS)}

SQLiteDLL = ‘sqlite3.dll’;

{$ELSEIF Defined(DARWIN)}

SQLiteDLL = ‘libsqlite3.dylib’;

{$linklib libsqlite3}

{$ELSEIF Defined(UNIX)}

SQLiteDLL = ‘sqlite3.so’;

{$IFEND}

// Return values for sqlite3_exec() and sqlite3_step()

const

SQLITE_OK = 0; // Successful result

(* beginning-of-error-codes *)

SQLITE_ERROR = 1; // SQL error or missing database

SQLITE_INTERNAL = 2; // An internal logic error in SQLite

SQLITE_PERM = 3; // Access permission denied

SQLITE_ABORT = 4; // Callback routine requested an abort

SQLITE_BUSY = 5; // The database file is locked

SQLITE_LOCKED = 6; // A table in the database is locked

SQLITE_NOMEM = 7; // A malloc() failed

SQLITE_READONLY = 8; // Attempt to write a readonly database

SQLITE_INTERRUPT = 9; // Operation terminated by sqlite3_interrupt()

SQLITE_IOERR = 10; // Some kind of disk I/O error occurred

SQLITE_CORRUPT = 11; // The database disk image is malformed

SQLITE_NOTFOUND = 12; // (Internal Only) Table or record not found

SQLITE_FULL = 13; // Insertion failed because database is full

SQLITE_CANTOPEN = 14; // Unable to open the database file

SQLITE_PROTOCOL = 15; // Database lock protocol error

SQLITE_EMPTY = 16; // Database is empty

SQLITE_SCHEMA = 17; // The database schema changed

SQLITE_TOOBIG = 18; // Too much data for one row of a table

SQLITE_CONSTRAINT = 19; // Abort due to contraint violation

SQLITE_MISMATCH = 20; // Data type mismatch

SQLITE_MISUSE = 21; // Library used incorrectly

SQLITE_NOLFS = 22; // Uses OS features not supported on host

SQLITE_AUTH = 23; // Authorization denied

SQLITE_FORMAT = 24; // Auxiliary database format error

SQLITE_RANGE = 25; // 2nd parameter to sqlite3_bind out of range

SQLITE_NOTADB = 26; // File opened that is not a database file

SQLITE_ROW = 100; // sqlite3_step() has another row ready

SQLITE_DONE = 101; // sqlite3_step() has finished executing

SQLITE_INTEGER = 1;

SQLITE_FLOAT = 2;

SQLITE_TEXT = 3;

SQLITE_BLOB = 4;

SQLITE_NULL = 5;

SQLITE_UTF8 = 1;

SQLITE_UTF16 = 2;

SQLITE_UTF16BE = 3;

SQLITE_UTF16LE = 4;

SQLITE_ANY = 5;

SQLITE_STATIC {: TSQLite3Destructor} = Pointer(0);

SQLITE_TRANSIENT {: TSQLite3Destructor} = Pointer(-1);

type

TSQLiteDB = Pointer;

TSQLiteResult = ^PAnsiChar;

TSQLiteStmt = Pointer;

TSQLiteBackup = pointer;

type

PPAnsiCharArray = ^TPAnsiCharArray;

TPAnsiCharArray = array[0 … (MaxInt div SizeOf(PAnsiChar))-1] of PAnsiChar;

type

TSQLiteExecCallback = function(UserData: Pointer; NumCols: integer; ColValues:

PPAnsiCharArray; ColNames: PPAnsiCharArray): integer; cdecl;

TSQLiteBusyHandlerCallback = function(UserData: Pointer; P2: integer): integer; cdecl;

//function prototype for define own collate

TCollateXCompare = function(UserData: pointer; Buf1Len: integer; Buf1: pointer;

Buf2Len: integer; Buf2: pointer): integer; cdecl;

function SQLite3_Open(filename: PAnsiChar; var db: TSQLiteDB): integer; cdecl; external SQLiteDLL name ‘sqlite3_open’;

function SQLite3_Close(db: TSQLiteDB): integer; cdecl; external SQLiteDLL name ‘sqlite3_close’;

function SQLite3_Exec(db: TSQLiteDB; SQLStatement: PAnsiChar; CallbackPtr: TSQLiteExecCallback; UserData: Pointer; var ErrMsg: PAnsiChar): integer; cdecl; external SQLiteDLL name ‘sqlite3_exec’;

function SQLite3_Version(): PAnsiChar; cdecl; external SQLiteDLL name ‘sqlite3_libversion’;

function SQLite3_ErrMsg(db: TSQLiteDB): PAnsiChar; cdecl; external SQLiteDLL name ‘sqlite3_errmsg’;

function SQLite3_ErrCode(db: TSQLiteDB): integer; cdecl; external SQLiteDLL name ‘sqlite3_errcode’;

procedure SQlite3_Free(P: PAnsiChar); cdecl; external SQLiteDLL name ‘sqlite3_free’;

function SQLite3_GetTable(db: TSQLiteDB; SQLStatement: PAnsiChar; var ResultPtr: TSQLiteResult; var RowCount: Cardinal; var ColCount: Cardinal; var ErrMsg: PAnsiChar): integer; cdecl; external SQLiteDLL name ‘sqlite3_get_table’;

procedure SQLite3_FreeTable(Table: TSQLiteResult); cdecl; external SQLiteDLL name ‘sqlite3_free_table’;

function SQLite3_Complete(P: PAnsiChar): boolean; cdecl; external SQLiteDLL name ‘sqlite3_complete’;

function SQLite3_LastInsertRowID(db: TSQLiteDB): int64; cdecl; external SQLiteDLL name ‘sqlite3_last_insert_rowid’;

procedure SQLite3_Interrupt(db: TSQLiteDB); cdecl; external SQLiteDLL name ‘sqlite3_interrupt’;

procedure SQLite3_BusyHandler(db: TSQLiteDB; CallbackPtr: TSQLiteBusyHandlerCallback; UserData: Pointer); cdecl; external SQLiteDLL name ‘sqlite3_busy_handler’;

procedure SQLite3_BusyTimeout(db: TSQLiteDB; TimeOut: integer); cdecl; external SQLiteDLL name ‘sqlite3_busy_timeout’;

function SQLite3_Changes(db: TSQLiteDB): integer; cdecl; external SQLiteDLL name ‘sqlite3_changes’;

function SQLite3_TotalChanges(db: TSQLiteDB): integer; cdecl; external SQLiteDLL name ‘sqlite3_total_changes’;

function SQLite3_Prepare(db: TSQLiteDB; SQLStatement: PAnsiChar; nBytes: integer; var hStmt: TSqliteStmt; var pzTail: PAnsiChar): integer; cdecl; external SQLiteDLL name ‘sqlite3_prepare’;

function SQLite3_Prepare_v2(db: TSQLiteDB; SQLStatement: PAnsiChar; nBytes: integer; var hStmt: TSqliteStmt; var pzTail: PAnsiChar): integer; cdecl; external SQLiteDLL name ‘sqlite3_prepare_v2’;

function SQLite3_ColumnCount(hStmt: TSqliteStmt): integer; cdecl; external SQLiteDLL name ‘sqlite3_column_count’;

function SQLite3_ColumnName(hStmt: TSqliteStmt; ColNum: integer): PAnsiChar; cdecl; external SQLiteDLL name ‘sqlite3_column_name’;

function SQLite3_ColumnDeclType(hStmt: TSqliteStmt; ColNum: integer): PAnsiChar; cdecl; external SQLiteDLL name ‘sqlite3_column_decltype’;

function SQLite3_Step(hStmt: TSqliteStmt): integer; cdecl; external SQLiteDLL name ‘sqlite3_step’;

function SQLite3_DataCount(hStmt: TSqliteStmt): integer; cdecl; external SQLiteDLL name ‘sqlite3_data_count’;

function SQLite3_ColumnBlob(hStmt: TSqliteStmt; ColNum: integer): pointer; cdecl; external SQLiteDLL name ‘sqlite3_column_blob’;

function SQLite3_ColumnBytes(hStmt: TSqliteStmt; ColNum: integer): integer; cdecl; external SQLiteDLL name ‘sqlite3_column_bytes’;

function SQLite3_ColumnDouble(hStmt: TSqliteStmt; ColNum: integer): double; cdecl; external SQLiteDLL name ‘sqlite3_column_double’;

function SQLite3_ColumnInt(hStmt: TSqliteStmt; ColNum: integer): integer; cdecl; external SQLiteDLL name ‘sqlite3_column_int’;

function SQLite3_ColumnText(hStmt: TSqliteStmt; ColNum: integer): PAnsiChar; cdecl; external SQLiteDLL name ‘sqlite3_column_text’;

function SQLite3_ColumnType(hStmt: TSqliteStmt; ColNum: integer): integer; cdecl; external SQLiteDLL name ‘sqlite3_column_type’;

function SQLite3_ColumnInt64(hStmt: TSqliteStmt; ColNum: integer): Int64; cdecl; external SQLiteDLL name ‘sqlite3_column_int64’;

function SQLite3_Finalize(hStmt: TSqliteStmt): integer; cdecl; external SQLiteDLL name ‘sqlite3_finalize’;

function SQLite3_Reset(hStmt: TSqliteStmt): integer; cdecl; external SQLiteDLL name ‘sqlite3_reset’;

function SQLite3_Backup_Init(DestDb: TSQLiteDB; DestDbName: PAnsiChar; SourceDb: TSQLiteDB; SourceDbName: PAnsiChar): TSqliteBackup; cdecl; external SQLiteDLL name ‘sqlite3_backup_init’;

function SQLite3_Backup_Step(hBackup: TSQLiteBackup; nPage: integer): integer; cdecl; external SQLiteDLL name ‘sqlite3_backup_step’;

function SQLite3_Backup_Finish(hBackup: TSQLiteBackup): integer; cdecl; external SQLiteDLL name ‘sqlite3_backup_finish’;

function SQLite3_Backup_Remaining(hBackup: TSQLiteBackup): integer; cdecl; external SQLiteDLL name ‘sqlite3_backup_remaining’;

function SQLite3_Backup_Pagecount(hBackup: TSQLiteBackup): integer; cdecl; external SQLiteDLL name ‘sqlite3_backup_pagecount’;

//

// In the SQL strings input to sqlite3_prepare() and sqlite3_prepare16(),

// one or more literals can be replace by a wildcard “?” or “:N:” where

// N is an integer. These value of these wildcard literals can be set

// using the routines listed below.

//

// In every case, the first parameter is a pointer to the sqlite3_stmt

// structure returned from sqlite3_prepare(). The second parameter is the

// index of the wildcard. The first “?” has an index of 1. “:N:” wildcards

// use the index N.

//

// The fifth parameter to sqlite3_bind_blob(), sqlite3_bind_text(), and

//sqlite3_bind_text16() is a destructor used to dispose of the BLOB or

//text after SQLite has finished with it. If the fifth argument is the

// special value SQLITE_STATIC, then the library assumes that the information

// is in static, unmanaged space and does not need to be freed. If the

// fifth argument has the value SQLITE_TRANSIENT, then SQLite makes its

// own private copy of the data.

//

// The sqlite3_bind_* routine must be called before sqlite3_step() after

// an sqlite3_prepare() or sqlite3_reset(). Unbound wildcards are interpreted

// as NULL.

//

type

TSQLite3Destructor = procedure(Ptr: Pointer); cdecl;

function sqlite3_bind_blob(hStmt: TSqliteStmt; ParamNum: integer;

ptrData: pointer; numBytes: integer; ptrDestructor: TSQLite3Destructor): integer;

cdecl; external SQLiteDLL name ‘sqlite3_bind_blob’;

function sqlite3_bind_text(hStmt: TSqliteStmt; ParamNum: integer;

Text: PAnsiChar; numBytes: integer; ptrDestructor: TSQLite3Destructor): integer;

cdecl; external SQLiteDLL name ‘sqlite3_bind_text’;

function sqlite3_bind_double(hStmt: TSqliteStmt; ParamNum: integer; Data: Double): integer;

cdecl; external SQLiteDLL name ‘sqlite3_bind_double’;

function sqlite3_bind_int(hStmt: TSqLiteStmt; ParamNum: integer; Data: integer): integer;

cdecl; external SQLiteDLL name ‘sqlite3_bind_int’;

function sqlite3_bind_int64(hStmt: TSqliteStmt; ParamNum: integer; Data: int64): integer;

cdecl; external SQLiteDLL name ‘sqlite3_bind_int64’;

function sqlite3_bind_null(hStmt: TSqliteStmt; ParamNum: integer): integer;

cdecl; external SQLiteDLL name ‘sqlite3_bind_null’;

function sqlite3_bind_parameter_index(hStmt: TSqliteStmt; zName: PAnsiChar): integer;

cdecl; external SQLiteDLL name ‘sqlite3_bind_parameter_index’;

function sqlite3_enable_shared_cache(Value: integer): integer; cdecl; external SQLiteDLL name ‘sqlite3_enable_shared_cache’;

//user collate definiton

function SQLite3_create_collation(db: TSQLiteDB; Name: PAnsiChar; eTextRep: integer;

UserData: pointer; xCompare: TCollateXCompare): integer; cdecl; external SQLiteDLL name ‘sqlite3_create_collation’;

function SQLiteFieldType(SQLiteFieldTypeCode: Integer): AnsiString;

function SQLiteErrorStr(SQLiteErrorCode: Integer): AnsiString;

implementation

uses

SysUtils;

function SQLiteFieldType(SQLiteFieldTypeCode: Integer): AnsiString;

begin

case SQLiteFieldTypeCode of

SQLITE_INTEGER: Result := 'Integer';

SQLITE_FLOAT: Result := 'Float';

SQLITE_TEXT: Result := 'Text';

SQLITE_BLOB: Result := 'Blob';

SQLITE_NULL: Result := 'Null';

else

Result := 'Unknown SQLite Field Type Code "' + IntToStr(SQLiteFieldTypeCode) + '"';

end;

end;

function SQLiteErrorStr(SQLiteErrorCode: Integer): AnsiString;

begin

case SQLiteErrorCode of

SQLITE_OK: Result := 'Successful result';

SQLITE_ERROR: Result := 'SQL error or missing database';

SQLITE_INTERNAL: Result := 'An internal logic error in SQLite';

SQLITE_PERM: Result := 'Access permission denied';

SQLITE_ABORT: Result := 'Callback routine requested an abort';

SQLITE_BUSY: Result := 'The database file is locked';

SQLITE_LOCKED: Result := 'A table in the database is locked';

SQLITE_NOMEM: Result := 'A malloc() failed';

SQLITE_READONLY: Result := 'Attempt to write a readonly database';

SQLITE_INTERRUPT: Result := 'Operation terminated by sqlite3_interrupt()';

SQLITE_IOERR: Result := 'Some kind of disk I/O error occurred';

SQLITE_CORRUPT: Result := 'The database disk image is malformed';

SQLITE_NOTFOUND: Result := '(Internal Only) Table or record not found';

SQLITE_FULL: Result := 'Insertion failed because database is full';

SQLITE_CANTOPEN: Result := 'Unable to open the database file';

SQLITE_PROTOCOL: Result := 'Database lock protocol error';

SQLITE_EMPTY: Result := 'Database is empty';

SQLITE_SCHEMA: Result := 'The database schema changed';

SQLITE_TOOBIG: Result := 'Too much data for one row of a table';

SQLITE_CONSTRAINT: Result := 'Abort due to contraint violation';

SQLITE_MISMATCH: Result := 'Data type mismatch';

SQLITE_MISUSE: Result := 'Library used incorrectly';

SQLITE_NOLFS: Result := 'Uses OS features not supported on host';

SQLITE_AUTH: Result := 'Authorization denied';

SQLITE_FORMAT: Result := 'Auxiliary database format error';

SQLITE_RANGE: Result := '2nd parameter to sqlite3_bind out of range';

SQLITE_NOTADB: Result := 'File opened that is not a database file';

SQLITE_ROW: Result := 'sqlite3_step() has another row ready';

SQLITE_DONE: Result := 'sqlite3_step() has finished executing';

else

Result := 'Unknown SQLite Error Code "' + IntToStr(SQLiteErrorCode) + '"';

end;

end;

function ColValueToStr(Value: PAnsiChar): AnsiString;

begin

if (Value = nil) then

Result := 'NULL'

else

Result := Value;

end;

end.

SQLiteTable3.pas源码：
unit SQLiteTable3;

{
Simple classes for using SQLite’s exec and get_table.

TSQLiteDatabase wraps the calls to open and close an SQLite database.
It also wraps SQLite_exec for queries that do not return a result set

TSQLiteTable wraps execution of SQL query.
It run query and read all returned rows to internal buffer.
It allows accessing fields by name as well as index and can move through a
result set forward and backwards, or randomly to any row.

TSQLiteUniTable wraps execution of SQL query.
It run query as TSQLiteTable, but reading just first row only!
You can step to next row (until not EOF) by ‘Next’ method.
You cannot step backwards! (So, it is called as UniDirectional result set.)
It not using any internal buffering, this class is very close to Sqlite API.
It allows accessing fields by name as well as index on actual row only.
Very good and fast for sequentional scanning of large result sets with minimal
memory footprint.

Warning! Do not close TSQLiteDatabase before any TSQLiteUniTable,
because query is closed on TSQLiteUniTable destructor and database connection
is used during TSQLiteUniTable live!

SQL parameter usage:
You can add named parameter values by call set of AddParam* methods.
Parameters will be used for first next SQL statement only.
Parameter name must be prefixed by ‘:’, ‘$’ or ‘@’ and same prefix must be
used in SQL statement!
Sample:
table.AddParamText(’:str’, ‘some value’);
s := table.GetTableString(‘SELECT value FROM sometable WHERE id=:str’);

Notes from Andrew Retmanski on prepared queries
The changes are as follows:

SQLiteTable3.pas

  • Added new boolean property Synchronised (this controls the SYNCHRONOUS pragma as I found that turning this OFF increased the write performance in my application)
  • Added new type TSQLiteQuery (this is just a simple record wrapper around the SQL string and a TSQLiteStmt pointer)
  • Added PrepareSQL method to prepare SQL query - returns TSQLiteQuery
  • Added ReleaseSQL method to release previously prepared query
  • Added overloaded BindSQL methods for Integer and String types - these set new values for the prepared query parameters
  • Added overloaded ExecSQL method to execute a prepared TSQLiteQuery

Usage of the new methods should be self explanatory but the process is in essence:

  1. Call PrepareSQL to return TSQLiteQuery 2. Call BindSQL for each parameter in the prepared query 3. Call ExecSQL to run the prepared query 4. Repeat steps 2 & 3 as required 5. Call ReleaseSQL to free SQLite resources

One other point - the Synchronised property throws an error if used inside a transaction.

Acknowledments
Adapted by Tim Anderson (tim@itwriting.com)
Originally created by Pablo Pissanetzky (pablo@myhtpc.net)
Modified and enhanced by Lukas Gebauer
Modified and enhanced by Tobias Gunkel
}

interface

{$IFDEF FPC}
{$MODE Delphi}{$H+}
{$ENDIF}

uses
{$IFDEF WIN32}
Windows,
{$ENDIF}
SQLite3, Classes, SysUtils;

const

dtInt = 1;
dtNumeric = 2;
dtStr = 3;
dtBlob = 4;
dtNull = 5;

type

ESQLiteException = class(Exception)
end;

TSQliteParam = class
public
name: string;
valuetype: integer;
valueinteger: int64;
valuefloat: double;
valuedata: string;
end;

THookQuery = procedure(Sender: TObject; SQL: String) of object;

TSQLiteQuery = record
SQL: String;
Statement: TSQLiteStmt;
end;

TSQLiteTable = class;
TSQLiteUniTable = class;

TSQLiteDatabase = class
private
fDB: TSQLiteDB;
fInTrans: boolean;
fSync: boolean;
fParams: TList;
FOnQuery: THookQuery;
procedure RaiseError(s: string; SQL: string);
procedure SetParams(Stmt: TSQLiteStmt);
procedure BindData(Stmt: TSQLiteStmt; const Bindings: array of const);
function GetRowsChanged: integer;
protected
procedure SetSynchronised(Value: boolean);
procedure DoQuery(value: string);
public
constructor Create(const FileName: string);
destructor Destroy; override;
function GetTable(const SQL: Ansistring): TSQLiteTable; overload;
function GetTable(const SQL: Ansistring; const Bindings: array of const): TSQLiteTable; overload;
procedure ExecSQL(const SQL: Ansistring); overload;
procedure ExecSQL(const SQL: Ansistring; const Bindings: array of const); overload;
procedure ExecSQL(Query: TSQLiteQuery); overload;
function PrepareSQL(const SQL: Ansistring): TSQLiteQuery;
procedure BindSQL(Query: TSQLiteQuery; const Index: Integer; const Value: Integer); overload;
procedure BindSQL(Query: TSQLiteQuery; const Index: Integer; const Value: String); overload;
procedure ReleaseSQL(Query: TSQLiteQuery);
function GetUniTable(const SQL: Ansistring): TSQLiteUniTable; overload;
function GetUniTable(const SQL: Ansistring; const Bindings: array of const): TSQLiteUniTable; overload;
function GetTableValue(const SQL: Ansistring): int64; overload;
function GetTableValue(const SQL: Ansistring; const Bindings: array of const): int64; overload;
function GetTableString(const SQL: Ansistring): string; overload;
function GetTableString(const SQL: Ansistring; const Bindings: array of const): string; overload;
procedure GetTableStrings(const SQL: Ansistring; const Value: TStrings);
procedure UpdateBlob(const SQL: Ansistring; BlobData: TStream);
procedure BeginTransaction;
procedure Commit;
procedure Rollback;
function TableExists(TableName: string): boolean;
function GetLastInsertRowID: int64;
function GetLastChangedRows: int64;
procedure SetTimeout(Value: integer);
function Backup(TargetDB: TSQLiteDatabase): integer; Overload;
function Backup(TargetDB: TSQLiteDatabase; targetName: Ansistring; sourceName: Ansistring): integer; Overload;
function Version: string;
procedure AddCustomCollate(name: string; xCompare: TCollateXCompare);
//adds collate named SYSTEM for correct data sorting by user’s locale
Procedure AddSystemCollate;
procedure ParamsClear;
procedure AddParamInt(name: string; value: int64);
procedure AddParamFloat(name: string; value: double);
procedure AddParamText(name: string; value: string);
procedure AddParamNull(name: string);

property DB: TSQLiteDB read fDB;

published
property IsTransactionOpen: boolean read fInTrans;
//database rows that were changed (or inserted or deleted) by the most recent SQL statement
property RowsChanged : integer read getRowsChanged;
property Synchronised: boolean read FSync write SetSynchronised;
property OnQuery: THookQuery read FOnQuery write FOnQuery;
end;

TSQLiteTable = class
private
fResults: TList;
fRowCount: cardinal;
fColCount: cardinal;
fCols: TStringList;
fColTypes: TList;
fRow: cardinal;
function GetFields(I: cardinal): string;
function GetEOF: boolean;
function GetBOF: boolean;
function GetColumns(I: integer): string;
function GetFieldByName(FieldName: string): string;
function GetFieldIndex(FieldName: string): integer;
function GetCount: integer;
function GetCountResult: integer;
public
constructor Create(DB: TSQLiteDatabase; const SQL: Ansistring); overload;
constructor Create(DB: TSQLiteDatabase; const SQL: Ansistring; const Bindings: array of const); overload;
destructor Destroy; override;
function FieldAsInteger(I: cardinal): int64;
function FieldAsBlob(I: cardinal): TMemoryStream;
function FieldAsBlobText(I: cardinal): string;
function FieldIsNull(I: cardinal): boolean;
function FieldAsString(I: cardinal): string;
function FieldAsDouble(I: cardinal): double;
function Next: boolean;
function Previous: boolean;
property EOF: boolean read GetEOF;
property BOF: boolean read GetBOF;
property Fields[I: cardinal]: string read GetFields;
property FieldByName[FieldName: string]: string read GetFieldByName;
property FieldIndex[FieldName: string]: integer read GetFieldIndex;
property Columns[I: integer]: string read GetColumns;
property ColCount: cardinal read fColCount;
property RowCount: cardinal read fRowCount;
property Row: cardinal read fRow;
function MoveFirst: boolean;
function MoveLast: boolean;
function MoveTo(position: cardinal): boolean;
property Count: integer read GetCount;
// The property CountResult is used when you execute count(*) queries.
// It returns 0 if the result set is empty or the value of the
// first field as an integer.
property CountResult: integer read GetCountResult;
end;

TSQLiteUniTable = class
private
fColCount: cardinal;
fCols: TStringList;
fRow: cardinal;
fEOF: boolean;
fStmt: TSQLiteStmt;
fDB: TSQLiteDatabase;
fSQL: string;
function GetFields(I: cardinal): string;
function GetColumns(I: integer): string;
function GetFieldByName(FieldName: string): string;
function GetFieldIndex(FieldName: string): integer;
public
constructor Create(DB: TSQLiteDatabase; const SQL: Ansistring); overload;
constructor Create(DB: TSQLiteDatabase; const SQL: Ansistring; const Bindings: array of const); overload;
destructor Destroy; override;
function FieldAsInteger(I: cardinal): int64;
function FieldAsBlob(I: cardinal): TMemoryStream;
function FieldAsBlobPtr(I: cardinal; out iNumBytes: integer): Pointer;
function FieldAsBlobText(I: cardinal): string;
function FieldIsNull(I: cardinal): boolean;
function FieldAsString(I: cardinal): string;
function FieldAsDouble(I: cardinal): double;
function Next: boolean;
property EOF: boolean read FEOF;
property Fields[I: cardinal]: string read GetFields;
property FieldByName[FieldName: string]: string read GetFieldByName;
property FieldIndex[FieldName: string]: integer read GetFieldIndex;
property Columns[I: integer]: string read GetColumns;
property ColCount: cardinal read fColCount;
property Row: cardinal read fRow;
end;

procedure DisposePointer(ptr: pointer); cdecl;

{$IFDEF WIN32}
function SystemCollate(Userdta: pointer; Buf1Len: integer; Buf1: pointer;
Buf2Len: integer; Buf2: pointer): integer; cdecl;
{$ENDIF}

implementation

procedure DisposePointer(ptr: pointer); cdecl;
begin
if assigned(ptr) then
freemem(ptr);
end;

{$IFDEF WIN32}
function SystemCollate(Userdta: pointer; Buf1Len: integer; Buf1: pointer;
Buf2Len: integer; Buf2: pointer): integer; cdecl;
begin
Result := CompareStringW(LOCALE_USER_DEFAULT, 0, PWideChar(Buf1), Buf1Len,
PWideChar(Buf2), Buf2Len) - 2;
end;
{$ENDIF}

#2

//------------------------------------------------------------------------------
// TSQLiteDatabase
//------------------------------------------------------------------------------

constructor TSQLiteDatabase.Create(const FileName: string);
var
Msg: PAnsiChar;
iResult: integer;
utf8FileName: UTF8string;
begin
inherited Create;
fParams := TList.Create;

self.fInTrans := False;

Msg := nil;
try
utf8FileName := UTF8String(FileName);
iResult := SQLite3_Open(PAnsiChar(utf8FileName), Fdb);

if iResult <> SQLITE_OK then
  if Assigned(Fdb) then
  begin
    Msg := Sqlite3_ErrMsg(Fdb);
    raise ESqliteException.CreateFmt('Failed to open database "%s" : %s',
      [FileName, Msg]);
  end
  else
    raise ESqliteException.CreateFmt('Failed to open database "%s" : unknown error',
      [FileName]);

//set a few configs
//L.G. Do not call it here. Because busy handler is not setted here,
// any share violation causing exception!

// self.ExecSQL(‘PRAGMA SYNCHRONOUS=NORMAL;’);
// self.ExecSQL(‘PRAGMA temp_store = MEMORY;’);

finally
if Assigned(Msg) then
SQLite3_Free(Msg);
end;

end;

//…

destructor TSQLiteDatabase.Destroy;
begin
if self.fInTrans then
self.Rollback; //assume rollback
if Assigned(fDB) then
SQLite3_Close(fDB);
ParamsClear;
fParams.Free;
inherited;
end;

function TSQLiteDatabase.GetLastInsertRowID: int64;
begin
Result := Sqlite3_LastInsertRowID(self.fDB);
end;

function TSQLiteDatabase.GetLastChangedRows: int64;
begin
Result := SQLite3_TotalChanges(self.fDB);
end;

//…

procedure TSQLiteDatabase.RaiseError(s: string; SQL: string);
//look up last error and raise an exception with an appropriate message
var
Msg: PAnsiChar;
ret : integer;
begin

Msg := nil;

ret := sqlite3_errcode(self.fDB);
if ret <> SQLITE_OK then
Msg := sqlite3_errmsg(self.fDB);

if Msg <> nil then
raise ESqliteException.CreateFmt(s +’.’#13’Error [%d]: %s.’#13’"%s": %s’, [ret, SQLiteErrorStr(ret),SQL, Msg])
else
raise ESqliteException.CreateFmt(s, [SQL, ‘No message’]);

end;

procedure TSQLiteDatabase.SetSynchronised(Value: boolean);
begin
if Value <> fSync then
begin
if Value then
ExecSQL(‘PRAGMA synchronous = ON;’)
else
ExecSQL(‘PRAGMA synchronous = OFF;’);
fSync := Value;
end;
end;

procedure TSQLiteDatabase.BindData(Stmt: TSQLiteStmt; const Bindings: array of const);
var
BlobMemStream: TCustomMemoryStream;
BlobStdStream: TStream;
DataPtr: Pointer;
DataSize: integer;
AnsiStr: AnsiString;
AnsiStrPtr: PAnsiString;
I: integer;
begin
for I := 0 to High(Bindings) do
begin
case Bindings[I].VType of
vtString,
vtAnsiString, vtPChar,
vtWideString, vtPWideChar,
vtChar, vtWideChar:
begin
case Bindings[I].VType of
vtString: begin // ShortString
AnsiStr := Bindings[I].VString^;
DataPtr := PAnsiChar(AnsiStr);
DataSize := Length(AnsiStr)+1;
end;
vtPChar: begin
DataPtr := Bindings[I].VPChar;
DataSize := -1;
end;
vtAnsiString: begin
AnsiStrPtr := PAnsiString(@Bindings[I].VAnsiString);
DataPtr := PAnsiChar(AnsiStrPtr^);
DataSize := Length(AnsiStrPtr^)+1;
end;
vtPWideChar: begin
DataPtr := PAnsiChar(UTF8Encode(WideString(Bindings[I].VPWideChar)));
DataSize := -1;
end;
vtWideString: begin
DataPtr := PAnsiChar(UTF8Encode(PWideString(@Bindings[I].VWideString)^));
DataSize := -1;
end;
vtChar: begin
DataPtr := PAnsiChar(String(Bindings[I].VChar));
DataSize := 2;
end;
vtWideChar: begin
DataPtr := PAnsiChar(UTF8Encode(WideString(Bindings[I].VWideChar)));
DataSize := -1;
end;
else
raise ESqliteException.Create(‘Unknown string-type’);
end;
if (sqlite3_bind_text(Stmt, I+1, DataPtr, DataSize, SQLITE_STATIC) <> SQLITE_OK) then
RaiseError(‘Could not bind text’, ‘BindData’);
end;
vtInteger:
if (sqlite3_bind_int(Stmt, I+1, Bindings[I].VInteger) <> SQLITE_OK) then
RaiseError(‘Could not bind integer’, ‘BindData’);
vtInt64:
if (sqlite3_bind_int64(Stmt, I+1, Bindings[I].VInt64^) <> SQLITE_OK) then
RaiseError(‘Could not bind int64’, ‘BindData’);
vtExtended:
if (sqlite3_bind_double(Stmt, I+1, Bindings[I].VExtended^) <> SQLITE_OK) then
RaiseError(‘Could not bind extended’, ‘BindData’);
vtBoolean:
if (sqlite3_bind_int(Stmt, I+1, Integer(Bindings[I].VBoolean)) <> SQLITE_OK) then
RaiseError(‘Could not bind boolean’, ‘BindData’);
vtPointer:
begin
if (Bindings[I].VPointer = nil) then
begin
if (sqlite3_bind_null(Stmt, I+1) <> SQLITE_OK) then
RaiseError(‘Could not bind null’, ‘BindData’);
end
else
raise ESqliteException.Create(‘Unhandled pointer (<> nil)’);
end;
vtObject:
begin
if (Bindings[I].VObject is TCustomMemoryStream) then
begin
BlobMemStream := TCustomMemoryStream(Bindings[I].VObject);
if (sqlite3_bind_blob(Stmt, I+1, @PAnsiChar(BlobMemStream.Memory)[BlobMemStream.Position],
BlobMemStream.Size-BlobMemStream.Position, SQLITE_STATIC) <> SQLITE_OK) then
begin
RaiseError(‘Could not bind BLOB’, ‘BindData’);
end;
end
else if (Bindings[I].VObject is TStream) then
begin
BlobStdStream := TStream(Bindings[I].VObject);
DataSize := BlobStdStream.Size;

      GetMem(DataPtr, DataSize);
      if (DataPtr = nil) then
        raise ESqliteException.Create('Error getting memory to save blob');

      BlobStdStream.Position := 0;
      BlobStdStream.Read(DataPtr^, DataSize);

      if (sqlite3_bind_blob(stmt, I+1, DataPtr, DataSize, @DisposePointer) <> SQLITE_OK) then
        RaiseError('Could not bind BLOB', 'BindData');
    end
    else             
      raise ESqliteException.Create('Unhandled object-type in binding');
  end
  else 
  begin
    raise ESqliteException.Create('Unhandled binding');
  end;
end;

end;
end;

procedure TSQLiteDatabase.ExecSQL(const SQL: Ansistring);
begin
ExecSQL(SQL, []);
end;

procedure TSQLiteDatabase.ExecSQL(const SQL: Ansistring; const Bindings: array of const);
var
Stmt: TSQLiteStmt;
NextSQLStatement: PAnsiChar;
iStepResult: integer;
begin
try
if Sqlite3_Prepare_v2(self.fDB, PAnsiChar(SQL), -1, Stmt, NextSQLStatement) <>
SQLITE_OK then
RaiseError(‘Error executing SQL’, SQL);
if (Stmt = nil) then
RaiseError(‘Could not prepare SQL statement’, SQL);
DoQuery(SQL);
SetParams(Stmt);
BindData(Stmt, Bindings);

iStepResult := Sqlite3_step(Stmt);
if (iStepResult <> SQLITE_DONE) then
  begin
  SQLite3_reset(stmt);
  RaiseError('Error executing SQL statement', SQL);
  end;

finally
if Assigned(Stmt) then
Sqlite3_Finalize(stmt);
end;
end;

{$WARNINGS OFF}
procedure TSQLiteDatabase.ExecSQL(Query: TSQLiteQuery);
var
iStepResult: integer;
begin
if Assigned(Query.Statement) then
begin
iStepResult := Sqlite3_step(Query.Statement);

if (iStepResult <> SQLITE_DONE) then
  begin
  SQLite3_reset(Query.Statement);
  RaiseError('Error executing prepared SQL statement', Query.SQL);
  end;
Sqlite3_Reset(Query.Statement);

end;
end;
{$WARNINGS ON}

{$WARNINGS OFF}
function TSQLiteDatabase.PrepareSQL(const SQL: Ansistring): TSQLiteQuery;
var
Stmt: TSQLiteStmt;
NextSQLStatement: PAnsiChar;
begin
Result.SQL := SQL;
Result.Statement := nil;

if Sqlite3_Prepare(self.fDB, PAnsiChar(SQL), -1, Stmt, NextSQLStatement) <>
SQLITE_OK then
RaiseError(‘Error executing SQL’, SQL)
else
Result.Statement := Stmt;

if (Result.Statement = nil) then
RaiseError(‘Could not prepare SQL statement’, SQL);
DoQuery(SQL);
end;
{$WARNINGS ON}

{$WARNINGS OFF}
procedure TSQLiteDatabase.BindSQL(Query: TSQLiteQuery; const Index: Integer; const Value: Integer);
begin
if Assigned(Query.Statement) then
sqlite3_Bind_Int(Query.Statement, Index, Value)
else
RaiseError(‘Could not bind integer to prepared SQL statement’, Query.SQL);
end;
{$WARNINGS ON}

{$WARNINGS OFF}
procedure TSQLiteDatabase.BindSQL(Query: TSQLiteQuery; const Index: Integer; const Value: String);
begin
if Assigned(Query.Statement) then
Sqlite3_Bind_Text(Query.Statement, Index, PAnsiChar(Value), Length(Value), Pointer(SQLITE_STATIC))
else
RaiseError(‘Could not bind string to prepared SQL statement’, Query.SQL);
end;
{$WARNINGS ON}

{$WARNINGS OFF}
procedure TSQLiteDatabase.ReleaseSQL(Query: TSQLiteQuery);
begin
if Assigned(Query.Statement) then
begin
Sqlite3_Finalize(Query.Statement);
Query.Statement := nil;
end
else
RaiseError(‘Could not release prepared SQL statement’, Query.SQL);
end;
{$WARNINGS ON}

procedure TSQLiteDatabase.UpdateBlob(const SQL: Ansistring; BlobData: TStream);
var
iSize: integer;
ptr: pointer;
Stmt: TSQLiteStmt;
Msg: PAnsiChar;
NextSQLStatement: PAnsiChar;
iStepResult: integer;
iBindResult: integer;
begin
//expects SQL of the form ‘UPDATE MYTABLE SET MYFIELD = ? WHERE MYKEY = 1’
if pos(’?’, SQL) = 0 then
RaiseError(‘SQL must include a ? parameter’, SQL);

Msg := nil;
try

if Sqlite3_Prepare_v2(self.fDB, PAnsiChar(SQL), -1, Stmt, NextSQLStatement) <>
  SQLITE_OK then
  RaiseError('Could not prepare SQL statement', SQL);

if (Stmt = nil) then
  RaiseError('Could not prepare SQL statement', SQL);
DoQuery(SQL);

//now bind the blob data
iSize := BlobData.size;

GetMem(ptr, iSize);

if (ptr = nil) then
  raise ESqliteException.CreateFmt('Error getting memory to save blob',
    [SQL, 'Error']);

BlobData.position := 0;
BlobData.Read(ptr^, iSize);

iBindResult := SQLite3_Bind_Blob(stmt, 1, ptr, iSize, @DisposePointer);

if iBindResult <> SQLITE_OK then
  RaiseError('Error binding blob to database', SQL);

iStepResult := Sqlite3_step(Stmt);

if (iStepResult <> SQLITE_DONE) then
  begin
  SQLite3_reset(stmt);
  RaiseError('Error executing SQL statement', SQL);
  end;

finally

if Assigned(Stmt) then
  Sqlite3_Finalize(stmt);

if Assigned(Msg) then
  SQLite3_Free(Msg);

end;

end;

#3

//…

function TSQLiteDatabase.GetTable(const SQL: Ansistring): TSQLiteTable;
begin
Result := TSQLiteTable.Create(Self, SQL);
end;

function TSQLiteDatabase.GetTable(const SQL: Ansistring; const Bindings: array of const): TSQLiteTable;
begin
Result := TSQLiteTable.Create(Self, SQL, Bindings);
end;

function TSQLiteDatabase.GetUniTable(const SQL: Ansistring): TSQLiteUniTable;
begin
Result := TSQLiteUniTable.Create(Self, SQL);
end;

function TSQLiteDatabase.GetUniTable(const SQL: Ansistring; const Bindings: array of const): TSQLiteUniTable;
begin
Result := TSQLiteUniTable.Create(Self, SQL, Bindings);
end;

function TSQLiteDatabase.GetTableValue(const SQL: Ansistring): int64;
begin
Result := GetTableValue(SQL, []);
end;

function TSQLiteDatabase.GetTableValue(const SQL: Ansistring; const Bindings: array of const): int64;
var
Table: TSQLiteUniTable;
begin
Result := 0;
Table := self.GetUniTable(SQL, Bindings);
try
if not Table.EOF then
Result := Table.FieldAsInteger(0);
finally
Table.Free;
end;
end;

function TSQLiteDatabase.GetTableString(const SQL: Ansistring): String;
begin
Result := GetTableString(SQL, []);
end;

function TSQLiteDatabase.GetTableString(const SQL: Ansistring; const Bindings: array of const): String;
var
Table: TSQLiteUniTable;
begin
Result := ‘’;
Table := self.GetUniTable(SQL, Bindings);
try
if not Table.EOF then
Result := Table.FieldAsString(0);
finally
Table.Free;
end;
end;

procedure TSQLiteDatabase.GetTableStrings(const SQL: Ansistring;
const Value: TStrings);
var
Table: TSQLiteUniTable;
begin
Value.Clear;
Table := self.GetUniTable(SQL);
try
while not table.EOF do
begin
Value.Add(Table.FieldAsString(0));
table.Next;
end;
finally
Table.Free;
end;
end;

procedure TSQLiteDatabase.BeginTransaction;
begin
if not self.fInTrans then
begin
self.ExecSQL(‘BEGIN TRANSACTION’);
self.fInTrans := True;
end
else
raise ESqliteException.Create(‘Transaction already open’);
end;

procedure TSQLiteDatabase.Commit;
begin
self.ExecSQL(‘COMMIT’);
self.fInTrans := False;
end;

procedure TSQLiteDatabase.Rollback;
begin
self.ExecSQL(‘ROLLBACK’);
self.fInTrans := False;
end;

function TSQLiteDatabase.TableExists(TableName: string): boolean;
var
sql: string;
ds: TSqliteTable;
begin
//returns true if table exists in the database
sql := ‘select [sql] from sqlite_master where [type] = ‘‘table’’ and lower(name) = ‘’’ +
lowercase(TableName) + ‘’’ ';
ds := self.GetTable(sql);
try
Result := (ds.Count > 0);
finally
ds.Free;
end;
end;

procedure TSQLiteDatabase.SetTimeout(Value: integer);
begin
SQLite3_BusyTimeout(self.fDB, Value);
end;

function TSQLiteDatabase.Version: string;
begin
Result := SQLite3_Version;
end;

procedure TSQLiteDatabase.AddCustomCollate(name: string;
xCompare: TCollateXCompare);
begin
sqlite3_create_collation(fdb, PAnsiChar(name), SQLITE_UTF8, nil, xCompare);
end;

procedure TSQLiteDatabase.AddSystemCollate;
begin
{$IFDEF WIN32}
sqlite3_create_collation(fdb, ‘SYSTEM’, SQLITE_UTF16LE, nil, @SystemCollate);
{$ENDIF}
end;

procedure TSQLiteDatabase.ParamsClear;
var
n: integer;
begin
for n := fParams.Count - 1 downto 0 do
TSQliteParam(fparams[n]).free;
fParams.Clear;
end;

procedure TSQLiteDatabase.AddParamInt(name: string; value: int64);
var
par: TSQliteParam;
begin
par := TSQliteParam.Create;
par.name := name;
par.valuetype := SQLITE_INTEGER;
par.valueinteger := value;
fParams.Add(par);
end;

procedure TSQLiteDatabase.AddParamFloat(name: string; value: double);
var
par: TSQliteParam;
begin
par := TSQliteParam.Create;
par.name := name;
par.valuetype := SQLITE_FLOAT;
par.valuefloat := value;
fParams.Add(par);
end;

procedure TSQLiteDatabase.AddParamText(name: string; value: string);
var
par: TSQliteParam;
begin
par := TSQliteParam.Create;
par.name := name;
par.valuetype := SQLITE_TEXT;
par.valuedata := value;
fParams.Add(par);
end;

procedure TSQLiteDatabase.AddParamNull(name: string);
var
par: TSQliteParam;
begin
par := TSQliteParam.Create;
par.name := name;
par.valuetype := SQLITE_NULL;
fParams.Add(par);
end;

procedure TSQLiteDatabase.SetParams(Stmt: TSQLiteStmt);
var
n: integer;
i: integer;
par: TSQliteParam;
begin
try
for n := 0 to fParams.Count - 1 do
begin
par := TSQliteParam(fParams[n]);
i := sqlite3_bind_parameter_index(Stmt, PAnsiChar(par.name));
if i > 0 then
begin
case par.valuetype of
SQLITE_INTEGER:
sqlite3_bind_int64(Stmt, i, par.valueinteger);
SQLITE_FLOAT:
sqlite3_bind_double(Stmt, i, par.valuefloat);
SQLITE_TEXT:
sqlite3_bind_text(Stmt, i, PAnsiChar(par.valuedata),
length(par.valuedata), SQLITE_TRANSIENT);
SQLITE_NULL:
sqlite3_bind_null(Stmt, i);
end;
end;
end;
finally
ParamsClear;
end;
end;

//database rows that were changed (or inserted or deleted) by the most recent SQL statement
function TSQLiteDatabase.GetRowsChanged: integer;
begin
Result := SQLite3_Changes(self.fDB);
end;

procedure TSQLiteDatabase.DoQuery(value: string);
begin
if assigned(OnQuery) then
OnQuery(Self, Value);
end;

//returns result of SQLITE3_Backup_Step
function TSQLiteDatabase.Backup(TargetDB: TSQLiteDatabase; targetName: Ansistring; sourceName: Ansistring): integer;
var
pBackup: TSQLiteBackup;
begin
pBackup := Sqlite3_backup_init(TargetDB.DB,PAnsiChar(targetName),self.DB,PAnsiChar(sourceName));

if (pBackup = nil) then
raise ESqliteException.Create(‘Could not initialize backup’)
else begin
try
result := SQLITE3_Backup_Step(pBackup,-1); //copies entire db
finally
SQLITE3_backup_finish(pBackup);
end;
end;
end;

function TSQliteDatabase.Backup(TargetDB: TSQLiteDatabase): integer;
begin
result := self.Backup(TargetDB,‘main’,‘main’);
end;

//------------------------------------------------------------------------------
// TSQLiteTable
//------------------------------------------------------------------------------

constructor TSQLiteTable.Create(DB: TSQLiteDatabase; const SQL: Ansistring);
begin
Create(DB, SQL, []);
end;

constructor TSQLiteTable.Create(DB: TSQLiteDatabase; const SQL: Ansistring; const Bindings: array of const);
var
Stmt: TSQLiteStmt;
NextSQLStatement: PAnsiChar;
iStepResult: integer;
ptr: pointer;
iNumBytes: integer;
thisBlobValue: TMemoryStream;
thisStringValue: pstring;
thisDoubleValue: pDouble;
thisIntValue: pInt64;
thisColType: pInteger;
i: integer;
DeclaredColType: PAnsiChar;
ActualColType: integer;
ptrValue: PAnsiChar;
begin
inherited create;
try
self.fRowCount := 0;
self.fColCount := 0;
//if there are several SQL statements in SQL, NextSQLStatment points to the
//beginning of the next one. Prepare only prepares the first SQL statement.
if Sqlite3_Prepare_v2(DB.fDB, PAnsiChar(SQL), -1, Stmt, NextSQLStatement) <> SQLITE_OK then
DB.RaiseError(‘Error executing SQL’, SQL);
if (Stmt = nil) then
DB.RaiseError(‘Could not prepare SQL statement’, SQL);
DB.DoQuery(SQL);
DB.SetParams(Stmt);
DB.BindData(Stmt, Bindings);

iStepResult := Sqlite3_step(Stmt);
while (iStepResult <> SQLITE_DONE) do
begin
  case iStepResult of
    SQLITE_ROW:
      begin
        Inc(fRowCount);
        if (fRowCount = 1) then
        begin
        //get data types
          fCols := TStringList.Create;
          fColTypes := TList.Create;
          fColCount := SQLite3_ColumnCount(stmt);
          for i := 0 to Pred(fColCount) do
            fCols.Add(AnsiUpperCase(Sqlite3_ColumnName(stmt, i)));
          for i := 0 to Pred(fColCount) do
          begin
            new(thisColType);
            DeclaredColType := Sqlite3_ColumnDeclType(stmt, i);
            if DeclaredColType = nil then
              thisColType^ := Sqlite3_ColumnType(stmt, i) //use the actual column type instead
            //seems to be needed for last_insert_rowid
            else
              if (DeclaredColType = 'INTEGER') or (DeclaredColType = 'BOOLEAN') then
                thisColType^ := dtInt
              else
                if (DeclaredColType = 'NUMERIC') or
                  (DeclaredColType = 'FLOAT') or
                  (DeclaredColType = 'DOUBLE') or
                  (DeclaredColType = 'REAL') then
                  thisColType^ := dtNumeric
                else
                  if DeclaredColType = 'BLOB' then
                    thisColType^ := dtBlob
                  else
                    thisColType^ := dtStr;
            fColTypes.Add(thiscoltype);
          end;
          fResults := TList.Create;
        end;

      //get column values
        for i := 0 to Pred(ColCount) do
        begin
          ActualColType := Sqlite3_ColumnType(stmt, i);
          if (ActualColType = SQLITE_NULL) then
            fResults.Add(nil)
          else
            if pInteger(fColTypes[i])^ = dtInt then
            begin
              new(thisintvalue);
              thisintvalue^ := Sqlite3_ColumnInt64(stmt, i);
              fResults.Add(thisintvalue);
            end
            else
              if pInteger(fColTypes[i])^ = dtNumeric then
              begin
                new(thisdoublevalue);
                thisdoublevalue^ := Sqlite3_ColumnDouble(stmt, i);
                fResults.Add(thisdoublevalue);
              end
              else
                if pInteger(fColTypes[i])^ = dtBlob then
                begin
                  iNumBytes := Sqlite3_ColumnBytes(stmt, i);
                  if iNumBytes = 0 then
                    thisblobvalue := nil
                  else
                  begin
                    thisblobvalue := TMemoryStream.Create;
                    thisblobvalue.position := 0;
                    ptr := Sqlite3_ColumnBlob(stmt, i);
                    thisblobvalue.writebuffer(ptr^, iNumBytes);
                  end;
                  fResults.Add(thisblobvalue);
                end
                else
                begin
                  new(thisstringvalue);
                  ptrValue := Sqlite3_ColumnText(stmt, i);
                  setstring(thisstringvalue^, ptrvalue, strlen(ptrvalue));
                  fResults.Add(thisstringvalue);
                end;
        end;
      end;
    SQLITE_BUSY:
      raise ESqliteException.CreateFmt('Could not prepare SQL statement',
        [SQL, 'SQLite is Busy']);
  else
    begin
    SQLite3_reset(stmt);
    DB.RaiseError('Could not retrieve data', SQL);
    end;
  end;
  iStepResult := Sqlite3_step(Stmt);
end;
fRow := 0;

finally
if Assigned(Stmt) then
Sqlite3_Finalize(stmt);
end;
end;

//…

destructor TSQLiteTable.Destroy;
var
i: cardinal;
iColNo: integer;
begin
if Assigned(fResults) then
begin
for i := 0 to fResults.Count - 1 do
begin
//check for blob type
iColNo := (i mod fColCount);
case pInteger(self.fColTypes[iColNo])^ of
dtBlob:
TMemoryStream(fResults[i]).Free;
dtStr:
if fResults[i] <> nil then
begin
setstring(string(fResults[i]^), nil, 0);
dispose(fResults[i]);
end;
else
dispose(fResults[i]);
end;
end;
fResults.Free;
end;
if Assigned(fCols) then
fCols.Free;
if Assigned(fColTypes) then
for i := 0 to fColTypes.Count - 1 do
dispose(fColTypes[i]);
fColTypes.Free;
inherited;
end;

//…

function TSQLiteTable.GetColumns(I: integer): string;
begin
Result := fCols[I];
end;

//…

function TSQLiteTable.GetCountResult: integer;
begin
if not EOF then
Result := StrToInt(Fields[0])
else
Result := 0;
end;

function TSQLiteTable.GetCount: integer;
begin
Result := FRowCount;
end;

//…

function TSQLiteTable.GetEOF: boolean;
begin
Result := fRow >= fRowCount;
end;

function TSQLiteTable.GetBOF: boolean;
begin
Result := fRow <= 0;
end;

//…

function TSQLiteTable.GetFieldByName(FieldName: string): string;
begin
Result := GetFields(self.GetFieldIndex(FieldName));
end;

function TSQLiteTable.GetFieldIndex(FieldName: string): integer;
begin
if (fCols = nil) then
begin
raise ESqliteException.Create(‘Field ’ + fieldname + ’ Not found. Empty dataset’);
exit;
end;

if (fCols.count = 0) then
begin
raise ESqliteException.Create(‘Field ’ + fieldname + ’ Not found. Empty dataset’);
exit;
end;

Result := fCols.IndexOf(AnsiUpperCase(FieldName));

if (result < 0) then
begin
raise ESqliteException.Create('Field not found in dataset: ’ + fieldname)
end;
end;

//…

function TSQLiteTable.GetFields(I: cardinal): string;
var
thisvalue: pstring;
thistype: integer;
begin
Result := ‘’;
if EOF then
raise ESqliteException.Create(‘Table is at End of File’);
//integer types are not stored in the resultset
//as strings, so they should be retrieved using the type-specific
//methods
thistype := pInteger(self.fColTypes[I])^;

case thistype of
dtStr:
begin
thisvalue := self.fResults[(self.frow * self.fColCount) + I];
if (thisvalue <> nil) then
Result := thisvalue^
else
Result := ‘’;
end;
dtInt:
Result := IntToStr(self.FieldAsInteger(I));
dtNumeric:
Result := FloatToStr(self.FieldAsDouble(I));
dtBlob:
Result := self.FieldAsBlobText(I);
else
Result := ‘’;
end;
end;

function TSqliteTable.FieldAsBlob(I: cardinal): TMemoryStream;
begin
if EOF then
raise ESqliteException.Create(‘Table is at End of File’);
if (self.fResults[(self.frow * self.fColCount) + I] = nil) then
Result := nil
else
if pInteger(self.fColTypes[I])^ = dtBlob then
Result := TMemoryStream(self.fResults[(self.frow * self.fColCount) + I])
else
raise ESqliteException.Create(‘Not a Blob field’);
end;

function TSqliteTable.FieldAsBlobText(I: cardinal): string;
var
MemStream: TMemoryStream;
Buffer: PAnsiChar;
begin
Result := ‘’;
MemStream := self.FieldAsBlob(I);
if MemStream <> nil then
if MemStream.Size > 0 then
begin
MemStream.position := 0;
{$IFDEF UNICODE}
Buffer := AnsiStralloc(MemStream.Size + 1);
{$ELSE}
Buffer := Stralloc(MemStream.Size + 1);
{$ENDIF}
MemStream.readbuffer(Buffer[0], MemStream.Size);
(Buffer + MemStream.Size)^ := chr(0);
SetString(Result, Buffer, MemStream.size);
strdispose(Buffer);
end;
//do not free the TMemoryStream here; it is freed when
//TSqliteTable is destroyed

end;

function TSqliteTable.FieldAsInteger(I: cardinal): int64;
begin
if EOF then
raise ESqliteException.Create(‘Table is at End of File’);
if (self.fResults[(self.frow * self.fColCount) + I] = nil) then
Result := 0
else
if pInteger(self.fColTypes[I])^ = dtInt then
Result := pInt64(self.fResults[(self.frow * self.fColCount) + I])^
else
if pInteger(self.fColTypes[I])^ = dtNumeric then
Result := trunc(strtofloat(pString(self.fResults[(self.frow * self.fColCount) + I])^))
else
raise ESqliteException.Create(‘Not an integer or numeric field’);
end;

function TSqliteTable.FieldAsDouble(I: cardinal): double;
begin
if EOF then
raise ESqliteException.Create(‘Table is at End of File’);
if (self.fResults[(self.frow * self.fColCount) + I] = nil) then
Result := 0
else
if pInteger(self.fColTypes[I])^ = dtInt then
Result := pInt64(self.fResults[(self.frow * self.fColCount) + I])^
else
if pInteger(self.fColTypes[I])^ = dtNumeric then
Result := pDouble(self.fResults[(self.frow * self.fColCount) + I])^
else
raise ESqliteException.Create(‘Not an integer or numeric field’);
end;

function TSqliteTable.FieldAsString(I: cardinal): string;
begin
if EOF then
raise ESqliteException.Create(‘Table is at End of File’);
if (self.fResults[(self.frow * self.fColCount) + I] = nil) then
Result := ‘’
else
Result := self.GetFields(I);
end;

function TSqliteTable.FieldIsNull(I: cardinal): boolean;
var
thisvalue: pointer;
begin
if EOF then
raise ESqliteException.Create(‘Table is at End of File’);
thisvalue := self.fResults[(self.frow * self.fColCount) + I];
Result := (thisvalue = nil);
end;

//…

function TSQLiteTable.Next: boolean;
begin
Result := False;
if not EOF then
begin
Inc(fRow);
Result := True;
end;
end;

function TSQLiteTable.Previous: boolean;
begin
Result := False;
if not BOF then
begin
Dec(fRow);
Result := True;
end;
end;

function TSQLiteTable.MoveFirst: boolean;
begin
Result := False;
if self.fRowCount > 0 then
begin
fRow := 0;
Result := True;
end;
end;

function TSQLiteTable.MoveLast: boolean;
begin
Result := False;
if self.fRowCount > 0 then
begin
fRow := fRowCount - 1;
Result := True;
end;
end;

{$WARNINGS OFF}
function TSQLiteTable.MoveTo(position: cardinal): boolean;
begin
Result := False;
if (self.fRowCount > 0) and (self.fRowCount > position) then
begin
fRow := position;
Result := True;
end;
end;
{$WARNINGS ON}

{ TSQLiteUniTable }

constructor TSQLiteUniTable.Create(DB: TSQLiteDatabase; const SQL: Ansistring);
begin
Create(DB, SQL, []);
end;

constructor TSQLiteUniTable.Create(DB: TSQLiteDatabase; const SQL: Ansistring; const Bindings: array of const);
var
NextSQLStatement: PAnsiChar;
i: integer;
begin
inherited create;
self.fDB := db;
self.fEOF := false;
self.fRow := 0;
self.fColCount := 0;
self.fSQL := SQL;
if Sqlite3_Prepare_v2(DB.fDB, PAnsiChar(SQL), -1, fStmt, NextSQLStatement) <> SQLITE_OK then
DB.RaiseError(‘Error executing SQL’, SQL);
if (fStmt = nil) then
DB.RaiseError(‘Could not prepare SQL statement’, SQL);
DB.DoQuery(SQL);
DB.SetParams(fStmt);
DB.BindData(fStmt, Bindings);

//get data types
fCols := TStringList.Create;
fColCount := SQLite3_ColumnCount(fstmt);
for i := 0 to Pred(fColCount) do
fCols.Add(AnsiUpperCase(Sqlite3_ColumnName(fstmt, i)));

Next;
end;

destructor TSQLiteUniTable.Destroy;
begin
if Assigned(fStmt) then
Sqlite3_Finalize(fstmt);
if Assigned(fCols) then
fCols.Free;
inherited;
end;

function TSQLiteUniTable.FieldAsBlob(I: cardinal): TMemoryStream;
var
iNumBytes: integer;
ptr: pointer;
begin
Result := TMemoryStream.Create;
iNumBytes := Sqlite3_ColumnBytes(fstmt, i);
if iNumBytes > 0 then
begin
ptr := Sqlite3_ColumnBlob(fstmt, i);
Result.writebuffer(ptr^, iNumBytes);
Result.Position := 0;
end;
end;

function TSQLiteUniTable.FieldAsBlobPtr(I: cardinal; out iNumBytes: integer): Pointer;
begin
iNumBytes := Sqlite3_ColumnBytes(fstmt, i);
Result := Sqlite3_ColumnBlob(fstmt, i);
end;

function TSQLiteUniTable.FieldAsBlobText(I: cardinal): string;
var
MemStream: TMemoryStream;
Buffer: PAnsiChar;
begin
Result := ‘’;
MemStream := self.FieldAsBlob(I);
if MemStream <> nil then
try
if MemStream.Size > 0 then
begin
MemStream.position := 0;
{$IFDEF UNICODE}
Buffer := AnsiStralloc(MemStream.Size + 1);
{$ELSE}
Buffer := Stralloc(MemStream.Size + 1);
{$ENDIF}
MemStream.readbuffer(Buffer[0], MemStream.Size);
(Buffer + MemStream.Size)^ := chr(0);
SetString(Result, Buffer, MemStream.size);
strdispose(Buffer);
end;
finally
MemStream.Free;
end
end;

function TSQLiteUniTable.FieldAsDouble(I: cardinal): double;
begin
Result := Sqlite3_ColumnDouble(fstmt, i);
end;

function TSQLiteUniTable.FieldAsInteger(I: cardinal): int64;
begin
Result := Sqlite3_ColumnInt64(fstmt, i);
end;

function TSQLiteUniTable.FieldAsString(I: cardinal): string;
begin
Result := self.GetFields(I);
end;

function TSQLiteUniTable.FieldIsNull(I: cardinal): boolean;
begin
Result := Sqlite3_ColumnText(fstmt, i) = nil;
end;

function TSQLiteUniTable.GetColumns(I: integer): string;
begin
Result := fCols[I];
end;

function TSQLiteUniTable.GetFieldByName(FieldName: string): string;
begin
Result := GetFields(self.GetFieldIndex(FieldName));
end;

function TSQLiteUniTable.GetFieldIndex(FieldName: string): integer;
begin
if (fCols = nil) then
begin
raise ESqliteException.Create(‘Field ’ + fieldname + ’ Not found. Empty dataset’);
exit;
end;

if (fCols.count = 0) then
begin
raise ESqliteException.Create(‘Field ’ + fieldname + ’ Not found. Empty dataset’);
exit;
end;

Result := fCols.IndexOf(AnsiUpperCase(FieldName));

if (result < 0) then
begin
raise ESqliteException.Create('Field not found in dataset: ’ + fieldname)
end;
end;

function TSQLiteUniTable.GetFields(I: cardinal): string;
begin
Result := Sqlite3_ColumnText(fstmt, i);
end;

function TSQLiteUniTable.Next: boolean;
var
iStepResult: integer;
begin
fEOF := true;
iStepResult := Sqlite3_step(fStmt);
case iStepResult of
SQLITE_ROW:
begin
fEOF := false;
inc(fRow);
end;
SQLITE_DONE:
// we are on the end of dataset
// return EOF=true only
;
else
begin
SQLite3_reset(fStmt);
fDB.RaiseError(‘Could not retrieve data’, fSQL);
end;
end;
Result := not fEOF;
end;

end.