SQLCANCEL( ) Function
Requests cancellation of an executing SQL statement.
SQLCANCEL( ) cancels the execution of SQLCOLUMNS( ), SQLEXEC( ), SQLMORERESULTS( ), and SQLTABLES( ) in asynchronous mode. To establish asynchronous mode, use the SQLSETPROP( ) function.
SQLCANCEL(nStatementHandle)
Parameters
- nStatementHandle
Specifies the active statement handle whose SQL statement is to be canceled.
Return Value
Numeric. SQLCANCEL( ) returns 1 if the SQL statement is successfully canceled, – 1 if there is a connection level error, and – 2 if there is an environment level error.
Example
The following example assumes SQLCONNECT( ) is successfully issued, and its return value is stored to a memory variable named gnHandle.
SQLEXEC( ) is used to sends a SQL statement to the data source and return the results to a cursor. SQLCANCEL( ) is issued to stop the query.
= SQLSETPROP(gnHandle, 'asynchronous', .T.) && To stop SQLEXEC( )
= SQLEXEC(gnHandle, 'SELECT * FROM authors')
= SQLCANCEL(gnHandle) && Wrong select statement, cancel