instantobjects-cvscommit

[Nando D. <na...@us...>]

Update of /cvsroot/instantobjects/Source/Core
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv17751/Core

Modified Files:
	InstantDBEvolution.pas InstantPersistence.pas 
Log Message:
added support for alternate data type for a database column; fixes some mapping problems in database evolution

Index: InstantDBEvolution.pas
===================================================================
RCS file: /cvsroot/instantobjects/Source/Core/InstantDBEvolution.pas,v
retrieving revision 1.3
retrieving revision 1.4
diff -C2 -d -r1.3 -r1.4
*** InstantDBEvolution.pas	4 Jul 2005 11:36:11 -0000	1.3
--- InstantDBEvolution.pas	13 Jul 2005 09:49:12 -0000	1.4
***************
*** 109,114 ****
          if Assigned(SourceFieldMetadata) then
          begin
!           if (TargetFieldMetadata.DataType <> SourceFieldMetadata.DataType) or
!              (TargetFieldMetadata.Size > SourceFieldMetadata.Size) then
              AppendAlterFieldCommand(CommandSequence, SourceFieldMetadata,
                TargetFieldMetadata);
--- 109,113 ----
          if Assigned(SourceFieldMetadata) then
          begin
!           if not SourceFieldMetadata.Equals(TargetFieldMetadata) then
              AppendAlterFieldCommand(CommandSequence, SourceFieldMetadata,
                TargetFieldMetadata);

Index: InstantPersistence.pas
===================================================================
RCS file: /cvsroot/instantobjects/Source/Core/InstantPersistence.pas,v
retrieving revision 1.45
retrieving revision 1.46
diff -C2 -d -r1.45 -r1.46
*** InstantPersistence.pas	13 Jul 2005 00:39:57 -0000	1.45
--- InstantPersistence.pas	13 Jul 2005 09:49:12 -0000	1.46
***************
*** 271,274 ****
--- 271,275 ----
  
    TInstantDataType = (dtInteger, dtFloat, dtCurrency, dtBoolean, dtString, dtMemo, dtDateTime, dtBlob);
+   TInstantDataTypes = set of TInstantDataType;
    TInstantFieldOption = (foRequired, foIndexed);
    TInstantFieldOptions = set of TInstantFieldOption;
***************
*** 281,290 ****
--- 282,306 ----
      FExternalTableName: string;
      FOriginalAttributeType: TInstantAttributeType;
+     FAlternateDataTypes: TInstantDataTypes;
      function GetCollection: TInstantFieldMetadatas;
      function GetTableMetadata: TInstantTableMetadata;
+   protected
+     function InternalEquals(const Other: TInstantMetadata): Boolean; override;
    public
      constructor Create(ACollection: TInstantFieldMetadatas); reintroduce;
+     // Returns True if one of the data types of Other (Other.DataType and
+     // Other.AlternateDataTypes) equals one of the data types of Self.
+     function DataTypesEqual(const Other: TInstantFieldMetadata): Boolean;
      property Collection: TInstantFieldMetadatas read GetCollection;
      property DataType: TInstantDataType read FDataType write FDataType;
+     // When field metadata is gathered from a database, there might be more
+     // TInstantDataType values that apply (for example when the database
+     // represents dtBoolean and dtInteger attributes with the same column type).
+     // In that case, a datatype is chosen as the value of the DataType
+     // property, and the others are put in AlternateDataTypes. The
+     // DataTypesEqual method considers both DataType and AlternateDataTypes when
+     // deciding upon data type "equality".
+     property AlternateDataTypes: TInstantDataTypes
+       read FAlternateDataTypes write FAlternateDataTypes;
      property Options: TInstantFieldOptions read FOptions write FOptions;
      property ExternalTableName: string read FExternalTableName write FExternalTableName;
***************
*** 3734,3737 ****
--- 3750,3761 ----
  end;
  
+ function TInstantFieldMetadata.DataTypesEqual(
+   const Other: TInstantFieldMetadata): Boolean;
+ begin
+   Result := (DataType = Other.DataType) or
+     (DataType in Other.AlternateDataTypes) or
+     (Other.DataType in AlternateDataTypes);
+ end;
+ 
  function TInstantFieldMetadata.GetCollection: TInstantFieldMetadatas;
  begin
***************
*** 3744,3747 ****
--- 3768,3782 ----
  end;
  
+ function TInstantFieldMetadata.InternalEquals(
+   const Other: TInstantMetadata): Boolean;
+ begin
+   Result := inherited InternalEquals(Other);
+   if Result then
+     Result := (Other is TInstantFieldMetadata) and
+       (DataTypesEqual(TInstantFieldMetadata(Other)));
+   if DataType = dtString then
+     Result := Result and (Size = TInstantFieldMetadata(Other).Size);
+ end;
+ 
  { TInstantFieldMetadatas }