Describes how SQL statements are executed.
DDL and DML statements can be executed incrementally.
The following
code fragment illustrates the incremental execution of a DDL statement. In
practice, this is no better than direct execution but shows the 'end conditions'
for running RDbIncremental
.
_LIT(KTxt,"DROP TABLE Suppliers"); ... RDbIncremental op; TInt step; TInt r=op.Execute(database,KTxt,step); while (step>0 && r==KErrNone) { r=op.Next(step); } op.Close(); ... // r has the error code from the operation
The following code fragment is an example of driving the incremental execution of a DML statement to completion.
_LIT(KTxt,"DELETE FROM Suppliers"); ... RDbUpdate update; TInt r=update.Execute(database,KTxt); while (r>0) { r=op.Next(); } op.Close(); ... // r has the error code from the operation // update.RowCount() returns the number of rows deleted, if successful