Delphi Examples: DbiAddIndex

Also see TTable.AddIndex in the Delphi online help. TTable.AddIndex will usually handle most of your indexing needs.

Example 1: Add an index to a Paradox 4.0 or 5.0 version table:

This is a primary index. This example uses the following input:

fDbiAddIndex1(Table1);

procedure fDbiAddIndex1(Tbl: TTable);

var

NewIndex: IDXDesc;

begin

if not Tbl.Exclusive then

raise EDatabaseError.Create('TTable.Exclusive must be set to ' +

'true in order to add an index to the table');

with NewIndex do begin

iIndexId:= 0;

bPrimary:= True;

bUnique:= True;

bDescending:= False;

bMaintained:= True;

bSubset:= False;

bExpIdx:= False;

iFldsInKey:= 1;

aiKeyFld[0]:= 1;

bCaseInsensitive:= False;

end;

Check(DbiAddIndex(Tbl.dbhandle, Tbl.handle, PChar(Tbl.TableName), szParadox, NewIndex, nil));

end;

Example 2: Add an index to a Paradox 4.0 or 5.0 version table.

This is a case insensitive, secondary, maintained index. This example uses the following input:

fDbiAddIndex2(Table1);

The procedure is defined as:

procedure fDbiAddIndex2(Tbl: TTable);

var

NewIndex: IDXDesc;

begin

if not Tbl.Exclusive then

raise EDatabaseError.Create

('TTable.Exclusive must be set to true in order to ' +

'add an index to the table');

with NewIndex do begin

szName:= 'NewIndex';

iIndexId:= 0;

bPrimary:= False;

bUnique:= False;

bDescending:= False;

bMaintained:= True;

bSubset:= False;

bExpIdx:= False;

iFldsInKey:= 1;

aiKeyFld[0]:= 2;

bCaseInsensitive:= True;

end;

Check(DbiAddIndex(Tbl.dbhandle, Tbl.handle, PChar(Tbl.TableName), szParadox, NewIndex, nil));

end;

Example 3: Add an index to a Paradox 7.0 version table.

This is a secondary unique / descending index. This example uses the following input:

fDbiAddIndex3(Table1);

The procedure is defined as:

procedure fDbiAddIndex3(Tbl: TTable);

var

NewIndex: IDXDesc;

begin

if not Tbl.Exclusive then

raise EDatabaseError.Create

('TTable.Exclusive must be set to true in order to ' +

'add an index to the table');

with NewIndex do begin

szName := 'NewIndex';

iIndexId := 0;

bPrimary := False;

bUnique := TRUE;

bDescending := True;

bMaintained := True;

bSubset := False;

bExpIdx := False;

iFldsInKey := 1;

aiKeyFld[0]:= 2;

bCaseInsensitive := True;

end;

Check(DbiAddIndex(Tbl.dbhandle, Tbl.handle, PChar(Tbl.TableName), szParadox, NewIndex, nil));

end;

Example 4: Add an index to a dBASE for Windows version table.

This example uses the following input:

fDbiAddIndex4(Table1);

The procedure is defined as:

procedure fDbiAddIndex4(Tbl: TTable);

var

NewIndex: IDXDesc;

begin

with NewIndex do begin

szTagName := 'NewIndex1';

bPrimary := False;

bUnique := False;

bDescending := False;

bMaintained := True;

bSubset := False;

bExpIdx := False;

iFldsInKey := 1;

aiKeyFld[0] := 2;

szKeyExp := ''; // Although this is not an Expression index,

szKeyCond := ''; // szKeyExp and szKeyCond must be set blank

bCaseInsensitive := False;

iBlockSize := 0;

end;

Check(DbiAddIndex(Tbl.dbhandle, Tbl.handle, PChar(Tbl.TableName), szDBASE, NewIndex, nil));

end;

Example 5: Add an expression index to a dBASE for Windows version table.

This example uses the following input:

fDbiAddIndex5(Table1);

The procedure is defined as:

procedure fDbiAddIndex5(Tbl: TTable);

var

NewIndex: IDXDesc;

begin

NewIndex.szTagName := 'EXPINDEX';

NewIndex.bPrimary := False;

NewIndex.bUnique := False;

NewIndex.bDescending := False;

NewIndex.bMaintained := True;

NewIndex.bSubset := False;

NewIndex.bExpIdx := True;

NewIndex.iFldsInKey := 1;

NewIndex.aiKeyFld[0] := 2;

NewIndex.szKeyExp := 'UPPER(FIELD1) + UPPER(FIELD2)';

NewIndex.szKeyCond := '';

NewIndex.bCaseInsensitive := False;

NewIndex.iBlockSize := 0;

Check(DbiAddIndex(Tbl.dbhandle, Tbl.handle, PChar(Tbl.TableName),

szDBASE, NewIndex, nil));

end;