以下是我所拥有的内容。
我得到的结果是:
我收到的错误信息是:
+++++++++++++++
+ id + myData +
+++++++++++++++
+ 1 + ABCD +
+ 2 + ABCDD +
+++++++++++++++
当我执行时
select char_length((select myData from mytable where id = 1)) as MyLength;
我得到的结果是:
++++++++++++
+ MyLength +
++++++++++++
+ 4 +
++++++++++++
但是当我执行查询时,
select char_length((select myData from mytable) as MyLength;
我收到的错误信息是:
DDL and DML statements are not allowed in the query panel for MySQL; only SELECT statements are allowed.