[Instantobjects-cvscommit] Source/Core InstantPersistence.pas,1.70,1.71 InstantDBBuild.pas,1.9,1.10

[Steven M. <sr...@us...>]

Update of /cvsroot/instantobjects/Source/Core
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv30114

Modified Files:
	InstantPersistence.pas InstantDBBuild.pas 
Log Message:
Added a generic 6 step statement SQL command class (TInstantDBBuildAlterFieldGenericSQLCommand) for evolving table fields.

Index: InstantPersistence.pas
===================================================================
RCS file: /cvsroot/instantobjects/Source/Core/InstantPersistence.pas,v
retrieving revision 1.70
retrieving revision 1.71
diff -C2 -d -r1.70 -r1.71
*** InstantPersistence.pas	27 Oct 2005 12:52:01 -0000	1.70
--- InstantPersistence.pas	31 Oct 2005 23:43:38 -0000	1.71
***************
*** 2290,2293 ****
--- 2290,2295 ----
      function InternalGenerateSelectTablesSQL: string; virtual;
      function InternalGenerateUpdateConcurrentSQL(Map: TInstantAttributeMap): string; virtual;
+     function InternalGenerateUpdateFieldCopySQL(OldMetadata, NewMetadata:
+         TInstantFieldMetadata): string; virtual;
      function InternalGenerateUpdateSQL(Map: TInstantAttributeMap): string; virtual;
      property Delimiters: string read GetDelimiters;
***************
*** 2312,2315 ****
--- 2314,2319 ----
      function GenerateSelectTablesSQL: string;
      function GenerateUpdateConcurrentSQL(Map: TInstantAttributeMap): string;
+     function GenerateUpdateFieldCopySQL(OldMetadata, NewMetadata:
+         TInstantFieldMetadata): string;
      function GenerateUpdateSQL(Map: TInstantAttributeMap): string;
    end;
***************
*** 12873,12876 ****
--- 12877,12886 ----
  end;
  
+ function TInstantSQLGenerator.GenerateUpdateFieldCopySQL(OldMetadata,
+     NewMetadata: TInstantFieldMetadata): string;
+ begin
+   Result := InternalGenerateUpdateFieldCopySQL(OldMetadata, NewMetadata);
+ end;
+ 
  function TInstantSQLGenerator.GenerateUpdateSQL
    (Map: TInstantAttributeMap): string;
***************
*** 13090,13093 ****
--- 13100,13112 ----
  end;
  
+ function TInstantSQLGenerator.InternalGenerateUpdateFieldCopySQL(OldMetadata,
+     NewMetadata: TInstantFieldMetadata): string;
+ begin
+   Result := Format('UPDATE %s SET %s = %s',
+                     [EmbraceTable(OldMetadata.TableMetadata.Name),
+                      EmbraceField(NewMetadata.Name),
+                      EmbraceField(OldMetadata.Name)]);
+ end;
+ 
  function TInstantSQLGenerator.InternalGenerateUpdateSQL
    (Map: TInstantAttributeMap): string;

Index: InstantDBBuild.pas
===================================================================
RCS file: /cvsroot/instantobjects/Source/Core/InstantDBBuild.pas,v
retrieving revision 1.9
retrieving revision 1.10
diff -C2 -d -r1.9 -r1.10
*** InstantDBBuild.pas	7 Sep 2005 10:52:04 -0000	1.9
--- InstantDBBuild.pas	31 Oct 2005 23:43:38 -0000	1.10
***************
*** 358,361 ****
--- 358,374 ----
    end;
  
+   TInstantDBBuildAlterFieldGenericSQLCommand = class(
+       TInstantDBBuildAlterFieldSQLCommand)
+   private
+     FTmpFieldMD: TInstantFieldMetadata;
+   protected
+     function GetDescription: string; override;
+     function GetSQLStatement(const Index: Integer): string; override;
+     function GetSQLStatementCount: Integer; override;
+     procedure InternalExecute; override;
+   public
+     destructor Destroy; override;
+   end;
+ 
  implementation
  
***************
*** 363,366 ****
--- 376,382 ----
    DB;
    
+ const
+   STmpFieldSuffix = '_XYZ_';
+ 
  { TInstantCustomDBBuilder }
  
***************
*** 999,1001 ****
--- 1015,1086 ----
  end;
  
+ { TInstantDBBuildAlterFieldSQLCommand }
+ 
+ destructor TInstantDBBuildAlterFieldGenericSQLCommand.Destroy;
+ begin
+   FTmpFieldMD.Free;
+   inherited;
+ end;
+ 
+ function TInstantDBBuildAlterFieldGenericSQLCommand.GetDescription: string;
+ begin
+   Result := Format('ALTER TABLE %s evolve column %s - multi-statement SQL.',
+                   [NewFieldMetadata.TableMetadata.Name, NewFieldMetadata.Name]);
+ end;
+ 
+ function TInstantDBBuildAlterFieldGenericSQLCommand.GetSQLStatement(const
+     Index: Integer): string;
+ 
+   function CreateTmpFieldMetadata(FieldMetadata: TInstantFieldMetadata):
+     TInstantFieldMetadata;
+   begin
+     Result := TInstantFieldMetadata.Create(FieldMetadata.Collection);
+     Result.Name := FieldMetadata.Name + STmpFieldSuffix;
+     Result.DataType := FieldMetadata.DataType;
+     Result.AlternateDataTypes := FieldMetadata.AlternateDataTypes;
+     Result.Options := FieldMetadata.Options;
+     Result.Size := FieldMetadata.Size;
+   end;
+ 
+ begin
+   Result := inherited GetSQLStatement(Index);
+ 
+   FTmpFieldMD := CreateTmpFieldMetadata(NewFieldMetadata);
+ 
+   with Broker.Generator do
+     case Index of
+       0 : Result := GenerateAddFieldSQL(FTmpFieldMD);
+ 
+       1 : Result := GenerateUpdateFieldCopySQL(OldFieldMetadata, FTmpFieldMD);
+ 
+       2 : Result := GenerateDropFieldSQL(OldFieldMetadata);
+ 
+       3 : Result := GenerateAddFieldSQL(NewFieldMetadata);
+ 
+       4 : Result := GenerateUpdateFieldCopySQL(FTmpFieldMD, NewFieldMetadata);
+ 
+       5 : Result := GenerateDropFieldSQL(FTmpFieldMD);
+     end;
+ end;
+ 
+ function TInstantDBBuildAlterFieldGenericSQLCommand.GetSQLStatementCount:
+     Integer;
+ begin
+   Result := 6;
+ end;
+ 
+ procedure TInstantDBBuildAlterFieldGenericSQLCommand.InternalExecute;
+ var
+   iStatement: Integer;
+ begin
+   try
+     for iStatement := 0 to Pred(GetSQLStatementCount) do
+       Broker.Execute(GetSQLStatement(iStatement));
+   except
+     if Assigned(FTmpFieldMD) then
+       Broker.Execute(Broker.Generator.GenerateDropFieldSQL(FTmpFieldMD));
+     raise;
+   end;
+ end;
+ 
  end.