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/// DB VCL read/only dataset from SynDB data access
// - this unit is a part of the freeware Synopse framework,
// licensed under a MPL/GPL/LGPL tri-license; version 1.18
unit SynDBVCL;
{
This file is part of Synopse framework.
Synopse framework. Copyright (C) 2018 Arnaud Bouchez
Synopse Informatique - https://synopse.info
*** BEGIN LICENSE BLOCK *****
Version: MPL 1.1/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Mozilla Public License Version
1.1 (the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.mozilla.org/MPL
Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
for the specific language governing rights and limitations under the License.
The Original Code is Synopse mORMot framework.
The Initial Developer of the Original Code is Arnaud Bouchez.
Portions created by the Initial Developer are Copyright (C) 2018
the Initial Developer. All Rights Reserved.
Contributor(s):
- Alfred Glaenzer (alf)
- Murat Ak
Alternatively, the contents of this file may be used under the terms of
either the GNU General Public License Version 2 or later (the "GPL"), or
the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the MPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the MPL, the GPL or the LGPL.
***** END LICENSE BLOCK *****
Version 1.17
- first public release, corresponding to Synopse mORMot Framework 1.17
Version 1.18
- BREAKING CHANGE: QueryToDataSet() and StatementToDataSet() renamed
as overloaded functions ToDataSet()
- now uses read/only TSynVirtualDataSet class for much faster process
and lower resource use - see SynDBMidasVCL.pas unit if you need
a TClientDataset writable (but slower) instance
- introducing TSynDBSQLDataSet as a re-usable TDataSet for queries
}
{$I Synopse.inc} // define HASINLINE USETYPEINFO CPU32 CPU64 OWNNORMTOUPPER
interface
uses
{$ifdef ISDELPHIXE2}System.SysUtils,{$else}SysUtils,{$endif}
Classes,
Contnrs,
SynCommons,
SynTable,
SynDB,
DB,
DBCommon,
SynVirtualDataSet;
type
/// read-only virtual TDataSet able to access a binary buffer as returned
// by TSQLStatement.FetchAllToBinary method or directly a TSQLStatement
TSynBinaryDataSet = class(TSynVirtualDataSet)
protected
fData: RawByteString;
fDataAccess: TSQLDBProxyStatementRandomAccess;
fTemp64: Int64;
procedure InternalInitFieldDefs; override;
function GetRecordCount: Integer; override;
function GetRowFieldData(Field: TField; RowIndex: integer;
out ResultLen: Integer; OnlyCheckNull: boolean): Pointer; override;
public
/// initialize the virtual TDataSet from a FetchAllToBinary() buffer
// - by default, ColumnDataSize would be computed from the supplied data,
// unless you set IgnoreColumnDataSize=true to set the value to 0 (and
// force e.g. SynDBVCL TSynBinaryDataSet.InternalInitFieldDefs define the
// field as ftDefaultMemo)
procedure From(const BinaryData: RawByteString;
DataRowPosition: PCardinalDynArray=nil; IgnoreColumnDataSize: boolean=false); overload; virtual;
/// initialize the virtual TDataSet from a SynDB TSQLDBStatement result set
// - the supplied ISQLDBRows instance can safely be freed by the caller,
// since a private binary copy will be owned by this instance (in Data)
// - by default, ColumnDataSize would be computed from the supplied data,
// unless you set IgnoreColumnDataSize=true to set the value to 0 (and
// force e.g. SynDBVCL TSynBinaryDataSet.InternalInitFieldDefs define the
// field as ftDefaultMemo)
procedure From(Statement: TSQLDBStatement; MaxRowCount: cardinal=0;
IgnoreColumnDataSize: boolean=false); overload; virtual;
/// finalize the class instance
destructor Destroy; override;
/// read-only access to the internal binary buffer
property Data: RawByteString read fData;
/// read-only access to the internal SynDB data
property DataAccess: TSQLDBProxyStatementRandomAccess read fDataAccess;
end;
/// TDataSet able to execute any SQL as SynDB's TSQLStatement result set
// - this class is not meant to be used by itself, but via TSynDBDataSet,
// defined in SynDBMidasVCL.pas, as a data provider able to apply updates to
// the remote SynDB connection
// - typical usage may be for instance over a SynDBRemote connection:
// ! props := TSQLDBWinHTTPConnectionProperties.Create(....);
// ! ds := TSynDBSQLDataSet.Create(MainForm);
// ! ds.CommandText := 'select * from people';
// ! ds.Open;
// ! // ... use ds
// ! ds.Close;
// ! ds.CommandText := 'select * from customer where id=:(10):';
// ! ds.Open;
// ! // ... use ds
TSynDBSQLDataSet = class(TSynBinaryDataSet)
protected
fConnection: TSQLDBConnectionProperties;
fCommandText: string;
procedure InternalOpen; override;
procedure InternalClose; override;
// IProvider implementation
procedure PSSetCommandText(const ACommandText: string); override;
function PSGetTableName: string; override;
function PSUpdateRecord(UpdateKind: TUpdateKind; Delta: TDataSet): Boolean; override;
function PSIsSQLBased: Boolean; override;
function PSIsSQLSupported: Boolean; override;
{$ifdef ISDELPHIXE3}
function PSExecuteStatement(const ASQL: string; AParams: TParams): Integer; overload; override;
function PSExecuteStatement(const ASQL: string; AParams: TParams; var ResultSet: TDataSet): Integer; overload; override;
{$else}
function PSExecuteStatement(const ASQL: string; AParams: TParams; ResultSet: Pointer=nil): Integer; overload; override;
{$endif}
public
/// initialize the internal TDataSet from a SynDB TSQLDBStatement result set
// - the supplied TSQLDBStatement can then be freed by the caller, since
// a private binary copy will be owned by this instance (in fDataSet.Data)
// - by default, ColumnDataSize would be computed from the supplied data,
// unless you set IgnoreColumnDataSize=true to set the value to 0 (and
// force e.g. SynDBVCL TSynBinaryDataSet.InternalInitFieldDefs define the
// field as ftDefaultMemo)
procedure From(Statement: TSQLDBStatement; MaxRowCount: cardinal=0;
IgnoreColumnDataSize: boolean=false); override;
/// the associated connection properties
property Connection: TSQLDBConnectionProperties read fConnection write fConnection;
published
/// the SQL statement to be executed
// - since this statement will be executed via Connection.ExecuteInlined,
// you can specify optionally inlined parameters to this SQL text
property CommandText: string read fCommandText write fCommandText;
end;
/// fetch a SynDB's TQuery result into a VCL DataSet
// - if aMaxRowCount>0, will return up to the specified number of rows
// - current implementation will return a TSynSQLStatementDataSet instance,
// using an optimized internal binary buffer: the supplied TQuery can be released
// - if you need a writable TDataSet, you can use the slower ToClientDataSet()
// function as defined in SynDBMidasVCL.pas
function ToDataSet(aOwner: TComponent; aStatement: SynDB.TQuery;
aMaxRowCount: integer=0): TSynBinaryDataSet; overload;
/// fetch a SynDB's TSQLDBStatement result into a VCL DataSet
// - just a wrapper around TSynSQLStatementDataSet.Create + Open
// - if aMaxRowCount>0, will return up to the specified number of rows
// - current implementation will return a TSynSQLStatementDataSet instance, using
// an optimized internal binary buffer: the supplied statement can be released
// - if you need a writable TDataSet, you can use the slower ToClientDataSet()
// function as defined in SynDBMidasVCL.pas
function ToDataSet(aOwner: TComponent; aStatement: TSQLDBStatement;
aMaxRowCount: integer=0): TSynBinaryDataSet; overload;
/// fetch a SynDB ISQLDBRows result set into a VCL DataSet
// - this overloaded function can use directly a result of the
// TSQLDBConnectionProperties.Execute() method, as such:
// ! ds1.DataSet := ToDataSet(self,props.Execute('select * from table',[]));
function ToDataSet(aOwner: TComponent; aStatement: ISQLDBRows;
aMaxRowCount: integer=0): TSynBinaryDataSet; overload;
/// fetch a SynDB's TSQLDBStatement.FetchAllToBinary buffer into a VCL DataSet
// - just a wrapper around TSynBinaryDataSet.Create + Open
// - if you need a writable TDataSet, you can use the slower ToClientDataSet()
// function as defined in SynDBMidasVCL.pas
function BinaryToDataSet(aOwner: TComponent;
const aBinaryData: RawByteString): TSynBinaryDataSet;
implementation
function ToDataSet(aOwner: TComponent; aStatement: SynDB.TQuery;
aMaxRowCount: integer): TSynBinaryDataSet;
begin
if aStatement=nil then
result := nil else
result := ToDataSet(aOwner,
aStatement.PreparedSQLDBStatement.Instance,aMaxRowCount);
end;
function ToDataSet(aOwner: TComponent; aStatement: TSQLDBStatement;
aMaxRowCount: integer): TSynBinaryDataSet;
begin
result := TSynBinaryDataSet.Create(aOwner);
result.From(aStatement,aMaxRowCount);
result.Open;
end;
function ToDataSet(aOwner: TComponent; aStatement: ISQLDBRows;
aMaxRowCount: integer): TSynBinaryDataSet;
begin
if aStatement=nil then
result := nil else
result := ToDataSet(aOwner,aStatement.Instance,aMaxRowCount);
end;
function BinaryToDataSet(aOwner: TComponent; const aBinaryData: RawByteString): TSynBinaryDataSet;
begin
result := TSynBinaryDataSet.Create(aOwner);
result.From(aBinaryData);
result.Open;
end;
{ TSynBinaryDataSet }
procedure TSynBinaryDataSet.From(const BinaryData: RawByteString;
DataRowPosition: PCardinalDynArray; IgnoreColumnDataSize: boolean);
begin
fData := BinaryData;
fDataAccess := TSQLDBProxyStatementRandomAccess.Create(
pointer(fData),length(fData),DataRowPosition,IgnoreColumnDataSize);
end;
procedure TSynBinaryDataSet.From(Statement: TSQLDBStatement; MaxRowCount: cardinal;
IgnoreColumnDataSize: boolean);
var DataStream: TRawByteStringStream;
DataRowPosition: TCardinalDynArray;
begin
DataStream := TRawByteStringStream.Create;
try
Statement.FetchAllToBinary(DataStream,MaxRowCount,@DataRowPosition);
From(DataStream.DataString,@DataRowPosition,IgnoreColumnDataSize);
finally
DataStream.Free;
end;
end;
destructor TSynBinaryDataSet.Destroy;
begin
inherited;
FreeAndNil(fDataAccess);
end;
function TSynBinaryDataSet.GetRecordCount: Integer;
begin
if fDataAccess=nil then
result := 0 else
result := fDataAccess.DataRowCount;
end;
procedure TSynBinaryDataSet.InternalInitFieldDefs;
var F: integer;
DBType: TFieldType;
begin
FieldDefs.Clear;
if fDataAccess=nil then
exit;
for F := 0 to fDataAccess.ColumnCount-1 do
with fDataAccess.Columns[F] do begin
case ColumnType of
SynTable.ftInt64: DBType := ftLargeint;
SynTable.ftDate: DBType := ftDateTime;
SynTable.ftUTF8:
if ColumnDataSize=0 then
DBType := ftDefaultMemo else
DBType := ftWideString; // means UnicodeString for Delphi 2009+
SynTable.ftBlob: DBType := ftBlob;
SynTable.ftDouble, SynTable.ftCurrency: DBType := ftFloat;
else raise EDatabaseError.CreateFmt(
'GetFieldData ColumnType=%s',[TSQLDBFieldTypeToString(ColumnType)]);
end;
FieldDefs.Add(UTF8ToString(ColumnName),DBType,ColumnDataSize);
end;
end;
function TSynBinaryDataSet.GetRowFieldData(Field: TField;
RowIndex: integer; out ResultLen: Integer; OnlyCheckNull: boolean): Pointer;
var F: integer;
begin
result := nil;
F := Field.Index;
if (fDataAccess=nil) or not fDataAccess.GotoRow(RowIndex) then
exit;
result := fDataAccess.ColumnData(F);
if (result<>nil) and not OnlyCheckNull then
case fDataAccess.Columns[F].ColumnType of
SynTable.ftInt64: begin
fTemp64 := FromVarInt64(PByte(result));
result := @fTemp64;
end;
SynTable.ftCurrency: begin // ftFloat expects a DOUBLE value
PDouble(@fTemp64)^ := PCurrency(result)^;
result := @fTemp64;
end;
SynTable.ftUTF8, SynTable.ftBlob:
resultLen := FromVarUInt32(PByte(result));
end; // other ColumnTypes are already in the expected format
end;
{ TSynDBSQLDataSet }
procedure TSynDBSQLDataSet.From(Statement: TSQLDBStatement; MaxRowCount: cardinal;
IgnoreColumnDataSize: boolean);
begin
inherited From(Statement,MaxRowCount,IgnoreColumnDataSize);
fConnection := Statement.Connection.Properties;
end;
procedure TSynDBSQLDataSet.InternalClose;
begin
inherited InternalClose;
FreeAndNil(fDataAccess);
fData := '';
end;
procedure TSynDBSQLDataSet.InternalOpen;
var Rows: ISQLDBRows;
begin
if fCommandText='' then begin
if fData<>'' then // called e.g. after From() method
inherited InternalOpen;
exit;
end;
Rows := fConnection.ExecuteInlined(StringToUTF8(fCommandText),true);
if Rows<>nil then begin
From(Rows.Instance);
inherited InternalOpen;
end;
end;
{$ifdef ISDELPHIXE3}
function TSynDBSQLDataSet.PSExecuteStatement(const ASQL: string;
AParams: TParams): Integer;
var DS: TDataSet;
begin
DS := nil;
result := PSExecuteStatement(ASQL,AParams,DS);
DS.Free;
end;
function TSynDBSQLDataSet.PSExecuteStatement(const ASQL: string;
AParams: TParams; var ResultSet: TDataSet): Integer;
{$else}
function TSynDBSQLDataSet.PSExecuteStatement(const ASQL: string;
AParams: TParams; ResultSet: Pointer): Integer;
{$endif}
var Stmt: ISQLDBStatement;
blob: TBlobData;
p: integer;
begin // only execute writes in current implementation
if fConnection=nil then
raise ESQLQueryException.CreateUTF8('%.PSExecuteStatement with Connection=nil',[self]);
Stmt := fConnection.NewThreadSafeStatementPrepared(StringToUTF8(ASQL),false);
if Stmt<>nil then
try
if AParams<>nil then
for p := 0 to AParams.Count-1 do
if aParams[p].DataType = ftBlob then begin
blob := aParams[p].AsBlob;
Stmt.BindBlob(p+1,pointer(blob),length(blob));
end else
Stmt.BindVariant(p+1,AParams[p].Value,False);
Stmt.ExecutePrepared;
result := Stmt.UpdateCount;
if result=0 then
result := 1; // optimistic result, even if SynDB returned 0
except
result := 0;
end else
result := 0;
end;
function TSynDBSQLDataSet.PSGetTableName: string;
begin
result := GetTableNameFromSQL(fCommandText);
end;
function TSynDBSQLDataSet.PSIsSQLBased: Boolean;
begin
result := true;
end;
function TSynDBSQLDataSet.PSIsSQLSupported: Boolean;
begin
result := true;
end;
procedure TSynDBSQLDataSet.PSSetCommandText(const ACommandText: string);
begin
inherited;
fCommandText := ACommandText;
end;
function TSynDBSQLDataSet.PSUpdateRecord(UpdateKind: TUpdateKind;
Delta: TDataSet): Boolean;
begin
result := false;
end;
end.