mysql GET DIAGNOSTICS 語法

MySQL 5.6 提供了 get diagnostic 語句來獲取錯誤緩沖區的內容，然后把這些內容輸出到不同范圍域的變量里，以便我們后續靈活操作 語法如下：

GET [CURRENT] DIAGNOSTICS
{
    statement_information_item
    [, statement_information_item] ... 
  | CONDITION condition_number
    condition_information_item
    [, condition_information_item] ...
}

statement_information_item:
    target = statement_information_item_name

condition_information_item:
    target = condition_information_item_name

statement_information_item_name:
    NUMBER
  | ROW_COUNT

condition_information_item_name:
    CLASS_ORIGIN
  | SUBCLASS_ORIGIN
  | RETURNED_SQLSTATE
  | MESSAGE_TEXT
  | MYSQL_ERRNO
  | CONSTRAINT_CATALOG
  | CONSTRAINT_SCHEMA
  | CONSTRAINT_NAME
  | CATALOG_NAME
  | SCHEMA_NAME
  | TABLE_NAME
  | COLUMN_NAME
  | CURSOR_NAME

condition_number, target:
    (see following discussion)

 

例子：獲取刪除表時的錯誤信息

mysql> DROP TABLE test.no_such_table;
ERROR 1051 (42S02): Unknown table 'test.no_such_table'
mysql> GET DIAGNOSTICS CONDITION 1
    ->   @p1 = RETURNED_SQLSTATE, @p2 = MESSAGE_TEXT;
mysql> SELECT @p1, @p2;
+-------+------------------------------------+
| @p1   | @p2                                |
+-------+------------------------------------+
| 42S02 | Unknown table 'test.no_such_table' |
+-------+------------------------------------+

 

參考：

13.6.7.3 GET DIAGNOSTICS Syntax