A new feature just got merged into mysql-trunk, the GET DIAGNOSTICS statement.

Many people have been asking for this for a very long time, so it is worth mentioning it.

mysql> select version();
+--------------+
| version()    |
+--------------+
| 5.6.4-m6-log |
+--------------+
1 row in set (0.00 sec)

mysql> drop table test.no_such_table;
ERROR 1051 (42S02): Unknown table 'test.no_such_table'

Why is it important ? In short, it allows to programmatically (i.e., in SQL) inspect what happened in a SQL exception.

mysql> get diagnostics condition 1
  @p1 = MESSAGE_TEXT,
  @p2 = RETURNED_SQLSTATE,
  @p3 = MYSQL_ERRNO,
  @p4 = SCHEMA_NAME,
  @p5 = TABLE_NAME;

Query OK, 0 rows

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