處理目的,當數據表中存在目標記錄時,執行UPDATE;當數據表中不存在目標記錄時,執行INSERT;從而減少一次查詢數據庫的過程
存儲過程設計如下:
CREATE PROCEDURE `pro_SaveData`(IN `sinst` varchar(500),IN `supdt` varchar(500))
BEGIN
#直接更新記錄
set @v_updsql=supdt;
prepare stmt from @v_updsql;
EXECUTE stmt;
#記錄不存在,執行INSERT
IF ROW_COUNT() =0 THEN
set @v_intsql=sinst;
prepare stmt from @v_intsql;
EXECUTE stmt;
END IF;
deallocate prepare stmt;
END;C#調用如下:
int r = data.ExecuteNonQuery(System.Data.CommandType.StoredProcedure,
@"CALL pro_SaveData (' INSERT INTO `table` VALUES ('1', 'username')',
'UPDATE table SET name='table222' WHERE id='1';')", null);