Mega Code Archive
Bde fonksiyonları 14
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Release the record lock on either the current record or all the record locks in the current session.
This example uses the following input:
fDbiRelRecordLock(Table1.Handle, True);
The procedure is:
procedure fDbiRelRecordLock(hTmpHandle:hDBICur; bAll: Boolean);
begin
Check(DbiRelRecordLock(hTmpHandle, bAll));
end;
//*********************************************************************************
Release all locks placed on a table by DbiAcqTableLock.
Delphi users can use the TTable.UnLockTable method rather than directly calling DbiRelTableLock. This method is defined as: Procedure TTable.UnLockTable(LockType: TLockType); This example uses the following input:
fDbiRelTableLock(Table1, True, dbiWRITELOCK);
The procedure is:
procedure fDbiRelTableLock(TblName: TTable; All: Boolean; Lock: DBILockType);
var
hNewCur: hDbiCur;
begin
Check(DbiGetCursorForTable(TblName.DBHandle,
PChar(TblName.TableName), '', hNewCur));
Check(DbiRelTableLock(hNewCur, All, Lock));
end;
Release all locks on the specified table.
Delphi users can use the TTable.UnlockTable method rather than directly calling DbiRelTableLock. This example uses the following input:
fDbiRelTableLock(Table1);
The procedure is:
procedure fDbiRelTableLock(TblName: TTable);
begin
Check(DbiRelTableLock(TblName.Handle, True, dbiWRITELOCK));
end;
//*************************************************************************************
Rename the table to the new table name. If ReOpen is True, reset the table's TableName and reopen the table.
Note: Most Delphi users should use TTable.RenameTable method.
procedure fDbiRenameTable(Table: TTable; NewName: string; ReOpen: Boolean);
var
hDb: hDBIDb;
Props: CURProps;
begin
if not Table.Active then
EDatabaseError.Create('Table must be open to complete operation');
if not Table.Exclusive then
EDBEngineError.Create(DBIERR_NEEDEXCLACCESS);
Check(DbiGetCursorProps(Table.Handle, Props));
// Get the Database Handle from the table cursor since Table.DBHandle will
// be invalid once the table is closed
Check(DbiGetObjFromObj(hDBIObj(Table.Handle), objDATABASE, hDBIObj(hDb)));
Table.Close;
Check(DbiRenameTable(hDb, PChar(Table.TableName), Props.szTableType, PChar(NewName)));
if ReOpen then begin
Table.TableName := NewName;
Table.Open;
end;
end;
//************************************************************************************
Reset the range of a table after using DbiSetRange.
This example removes constraints on a result set.
function fDbiResetRange(Handle: hDBICur): DBIResult;
begin
Return := DbiResetRange(Handle); { remove range }
Check(Return); { raise an exception if that failed }
end;
//***********************************************************************************
Save all updated records associated with hTmpHandle to disk.
This example uses the following input
fDbiSaveChanges(Table1.Handle);
The procedure is:
procedure fDbiSaveChanges(hTmpHandle:hDBICur);
begin
Check(DbiSaveChanges(hTmpHandle));
end;
//***********************************************************************************
Set the current session.
Note: Most Delphi users should use Sessions (TSessionList) and Session (TSession) to alter the current session.
This example uses the following input:
fDbiSetCurrSession(Session.Handle);
The procedure is:
procedure fDbiSetCurrSession(hSes: hDBISes);
begin
Check(DbiSetCurrSession(hSes));
end;
//***********************************************************************************
Set the date format for the current session.
This example uses the following input:
fDbiSetDateFormat;
The procedure is:
procedure fDbiSetDateFormat;
var
fDate : FMTDate;
begin
// Specifies date separator character
fDate.szDateSeparator := '/'; { }
// Date format. 0 = MDY, 1 = DMY, 2 = YMD
fDate.iDateMode := 0;
// If TRUE, write year as four digits
fDate.bFourDigitYear := False;
// On input add 1900 to year if True
fDate.bYearBiased := False;
// Month displayed with a leading zero if True
fDate.bMonthLeadingZero := False;
//. Day displayed with leading zero if True
fDate.bDayLeadingZero := False;
Check(DbiSetDateFormat(fDate));
end;
//*********************************************************************************
Set the current working directory.
The function fDbiSetDirectory for the database specified in the hdb parameter to the directory in the Dir parameter. This example uses the following input:
fDbiSetDirectory(Database1.Handle, 'C:\Tables');
The procedure is:
procedure fDbiSetDirectory(hdb: hDbiDb; Dir: string);
begin
Check(DbiSetDirectory(hdb, PChar(Dir)));
end;
//*********************************************************************************
Set a field map for the current table.
Note: Most Delphi users should use the Fields Editor of a TTable to set the field mapping.
This example uses the following input:
fDbiSetFieldMap(CustomerTbl, [CustomerTbl.FieldByName('Company'),
CustomerTbl.FieldByName('City')]);
The procedure is:
procedure fDbiSetFieldMap(Table: TTable; const Fields: array of TField);
var
CurrentElement, Elements, FldNum: Integer;
pFields, pOrigFields, pF, pOF: pFLDDesc;
begin
Elements := sizeof(Fields) div sizeof(TField);
pFields := AllocMem(Elements * sizeof(FLDDesc));
pOrigFields := AllocMem(Table.FieldCount * sizeof(FLDDesc));
pF := pFields;
try
// Get the original field descriptors
Check(DbiGetFieldDescs(Table.Handle, pOrigFields));
// Iterate through the original fields and create a pFLDDesc structure
// for the new field map structure
for CurrentElement := 0 to (Elements – 1) do begin
pOF := pOrigFields;
for FldNum := 1 to Table.FieldCount do begin
// Add only the field names that match
if (StrIComp(PChar(Fields[CurrentElement].FieldName), pOF.szName) = 0)
then begin
// Move the original FLDDesc to the new FLDDesc
move(pOF^, pF^, sizeof(FLDDesc));
Inc(pF);
break;
end
else
Inc(pOF);
end;
end;
Check(DbiSetFieldMap(Table.Handle, Elements, pFields));
finally
FreeMem(pFields, Elements * sizeof(FLDDesc));
FreeMem(pOrigFields, Table.FieldCount * sizeof(FLDDesc));
end;
end;
//********************************************************************************
Set the specified session's lock retry time. This example uses the following input:
fDbiSetLockRetry(Session, 100);
The procedure is:
procedure fDbiSetLockRetry(LockSession: TSession; Wait: Integer);
var
OriginalSession: TSession;
begin
// Save the current session
OriginalSession := Sessions.CurrentSession;
// Set the current session to the specified session
Sessions.CurrentSession := LockSession;
// Set the lock retry time
Check(DbiSetLockRetry(Wait));
// Set the current session back to the original session
Sessions.CurrentSession := OriginalSession;
end;
//*********************************************************************************
Set the private directory.
Delphi programs should use the TSession, PrivateDir property rather than using the dbi function directly. This sets the private directory for Paradox tables. For all drivers, all temporary or auxiliary files are created/kept in this directory. This example uses the following input:
fDbiSetPrivateDir('C:\Temp');
The procedure is:
procedure fDbiSetPrivateDir(Dir: string);
begin
Check(DbiSetPrivateDir(PChar(Dir)));
end;
//**********************************************************************************
Example1: Enable or disable soft deletes.
Set soft deletes to True or False depending on the Boolean parameter SoftDelete in the TTable specified in the Table parameter. This example uses the following input:
fDbiSetProp1(AnimalTbl, True);
The procedure is:
procedure fDbiSetProp1(Table: TTable; SoftDelete: Boolean);
var
rslt: DBIResult;
Props: CURProps;
begin
Check(DbiGetCursorProps(Table.Handle, Props));
if (Props.szTableType <> szDBASE) then
raise EDBEngineError.Create(DBIERR_NOTSUPPORTED);
// Make sure that the property can be set
rslt := DbiValidateProp(hDBIObj(Table.Handle), curSOFTDELETEON, True);
if (rslt = DBIERR_NONE) then
// Set the property
Check(DbiSetProp(hDBIObj(Table.Handle), curSOFTDELETEON, Longint(SoftDelete)))
else
raise EDBEngineError.Create(rslt);
end;
Example 2: Specify the maximum number of rows to be fetched from an SQL statement.
Set the maximum rows fetched in the parameter MaxRows, for the SQL table specified in the Table parameter. This example uses the following input:
fDbiSetProp2(IBTable, 100);
The procedure is:
procedure fDbiSetProp2(Table: TTable; MaxRows: Longint);
var
rslt: DBIResult;
DBType: string;
Len: Word;
begin
SetLength(DBType, DBIMAXNAMELEN);
Check(DbiGetProp(hDBIObj(Table.DBHandle), dbDATABASETYPE,
PChar(DBType), DBIMAXNAMELEN, Len));
SetLength(DBType, StrLen(PChar(DBType)));
// Make sure the table type is not dBASE or Paradox (must be SQL based)
if (DBType = 'STANDARD') then
raise EDBEngineError.Create(DBIERR_NOTSUPPORTED);
// Make sure that the property can be set
rslt := DbiValidateProp(hDBIObj(Table.Handle), curMAXROWS, True);
if (rslt = DBIERR_NONE) then
// Set the property
Check(DbiSetProp(hDBIObj(Table.Handle), curMAXROWS, MaxRows))
else
raise EDBEngineError.Create(rslt);
end;
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