Help Center/ GaussDB/ Centralized_8.x/ Application Development Guide/ ECPG-based Development/ Running SQL Commands/ Embedded SQL Commands/ WHENEVER
Updated on 2024-06-03 GMT+08:00
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WHENEVER

Description

Defines a behavior that is invoked when an SQL execution exception occurs (row not found, SQL alarm, or error).

Syntax

WHENEVER { NOT FOUND | SQLERROR | SQLWARNING } action

Parameters

For details about the parameter description, see Setting Callbacks.

Examples

EXEC SQL WHENEVER NOT FOUND CONTINUE; 
EXEC SQL WHENEVER NOT FOUND DO BREAK; 
EXEC SQL WHENEVER SQLWARNING SQLPRINT; 
EXEC SQL WHENEVER SQLWARNING DO warn(); 
EXEC SQL WHENEVER SQLERROR sqlprint; 
EXEC SQL WHENEVER SQLERROR SQLCALL print2(); 
EXEC SQL WHENEVER SQLERROR DO handle_error("select"); 
EXEC SQL WHENEVER SQLERROR DO sqlnotice(NULL, NONO);
EXEC SQL WHENEVER SQLERROR DO sqlprint(); 
EXEC SQL WHENEVER SQLERROR GOTO error_label; 
EXEC SQL WHENEVER SQLERROR STOP;
Use WHENEVER NOT FOUND BREAK to process the loop of the result set. The following is a complete example: 
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

int main(void)
{
    EXEC SQL CONNECT TO testdb AS con1;
    EXEC SQL ALLOCATE DESCRIPTOR d;
    EXEC SQL DECLARE cur CURSOR FOR SELECT current_database(), 'hoge', 256;
    EXEC SQL OPEN cur;
    EXEC SQL BEGIN DECLARE SECTION;
    char* d1;
    char* d2;
    EXEC SQL END DECLARE SECTION;
    /* When the end of the result set is reached, exit the loop. */
    EXEC SQL WHENEVER NOT FOUND DO BREAK;

    while (1)
    {
        EXEC SQL FETCH NEXT FROM cur INTO SQL DESCRIPTOR d;
        exec sql get descriptor d value 1 :d1=DATA;
        exec sql get descriptor d value 2 :d2=DATA;
        printf("d1 is %s,%s\n", d1, d2) ;
    }
     EXEC SQL CLOSE cur;
     EXEC SQL COMMIT;
     EXEC SQL DEALLOCATE DESCRIPTOR d;
     EXEC SQL DISCONNECT ALL;
     return 0;
}
Parent topic: Embedded SQL Commands