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Trigger

Define Trigger Function

int 
stu_trigger (xdb_conn_t *pConn, xdb_res_t* pRes, uint32_t type, xdb_row_t *pNewRow, xdb_row_t *pOldRow, void *pArg)
{
    switch (type) {
    case XDB_TRIG_AFT_INS:
        printf ("insert student: id %d name '%s' age %d\n", 
                    xdb_col_int(pRes, pNewRow, "id"), 
                    xdb_col_str(pRes, pNewRow, "name"), 
                    xdb_col_int(pRes, pNewRow, "age"));
        break;
    case XDB_TRIG_AFT_DEL:
        printf ("delete student id %d: name '%s' age %d\n", 
                    xdb_col_int(pRes, pNewRow, "id"), 
                    xdb_col_str(pRes, pNewRow, "name"), 
                    xdb_col_int(pRes, pNewRow, "age"));
        break;
    case XDB_TRIG_AFT_UPD:
        printf ("update student id %d: \n", 
                    xdb_col_int(pRes, pNewRow, "id"));
        printf ("    age:  '%d' -> '%d'\n", 
                    xdb_col_int(pRes, pOldRow, "age"), 
                    xdb_col_int(pRes, pNewRow, "age"));
        break;
    }
    return 0;
}

Create Trigger Function

xdb_create_func ("stu_trig", XDB_FUNC_TRIG, "C", stu_trigger, NULL);

Create Trigger

CREATE TRIGGER stu_ins AFTER INSERT ON student CALL stu_trig
CREATE TRIGGER stu_upd AFTER UPDATE ON student CALL stu_trig    
CREATE TRIGGER stu_del AFTER DELETE ON student CALL stu_trig

xdb_exec (pConn, "CREATE TRIGGER stu_ins AFTER INSERT ON student CALL stu_trig");
xdb_exec (pConn, "CREATE TRIGGER stu_upd AFTER UPDATE ON student CALL stu_trig");
xdb_exec (pConn, "CREATE TRIGGER stu_del AFTER DELETE ON student CALL stu_trig");

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