创建表执行出错
DDL的执行是一个分布式处理过程，出错可能导致各个分片表结构不一致，所以需要进行手动清理，详细操作步骤如下：
- PolarDB-X会提供基本的错误描述信息，比如语法错误等。如果错误信息太长，则会提示您使用
SHOW WARNINGS来查看每个分库执行失败的原因。 - 执行
SHOW TOPOLOGY命令来查看物理表的拓扑结构。
SHOW TOPOLOGY FROM multi_db_multi_tbl; +------+-----------------+-----------------------+ | ID | GROUP_NAME | TABLE_NAME | +------+-----------------+-----------------------+ | 0 | corona_qatest_0 | multi_db_multi_tbl_00 | | 1 | corona_qatest_0 | multi_db_multi_tbl_01 | | 2 | corona_qatest_0 | multi_db_multi_tbl_02 | | 3 | corona_qatest_1 | multi_db_multi_tbl_03 | | 4 | corona_qatest_1 | multi_db_multi_tbl_04 | | 5 | corona_qatest_1 | multi_db_multi_tbl_05 | | 6 | corona_qatest_2 | multi_db_multi_tbl_06 | | 7 | corona_qatest_2 | multi_db_multi_tbl_07 | | 8 | corona_qatest_2 | multi_db_multi_tbl_08 | | 9 | corona_qatest_3 | multi_db_multi_tbl_09 | | 10 | corona_qatest_3 | multi_db_multi_tbl_10 | | 11 | corona_qatest_3 | multi_db_multi_tbl_11 | +------+-----------------+-----------------------+ 12 rows in set (0.21 sec)
- 执行
CHECK TABLE tablename语句来查看逻辑表是否创建成功。例如下面的例子展示了multi_db_multi_tbl的某个物理分表没有创建成功时的情况。
mysql> check table multi_db_multi_tbl;
+-------------------------------------------------+-------+----------+---------------------------------------------------------------------------+| TABLE | OP | MSG_TYPE | MSG_TEXT |
+-------------------------------------------------+-------+----------+---------------------------------------------------------------------------+
| andor_mysql_qatest. multi_db_multi_tbl | check | Error | Table 'corona_qatest_0. multi_db_multi_tbl_02' doesn't exist |
+-------------------------------------------------+-------+----------+---------------------------------------------------------------------------+
1 row in set (0.16 sec)
- 使用幂等的方式重新执行建表或删表操作，该操作会创建或删除剩余的物理表。
CREATE TABLE IF NOT EXISTS table1
(id int, name varchar(30), primary key(id))
dbpartition by hash(id);
DROP TABLE IF EXISTS table1;
建索引失败或加列失败
建索引失败或加列失败的处理方法跟上面建表失败的处理类似，详情请参见如何正确处理DDL异常。
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