Note : ALTER TABLE is used for altering a table means to change column name, size, drop column. CHANGE COLUMN and MODIFY COLUMN commands ... ... <看更多>

更改一个表的定义。 概要. ALTER TABLE [ONLY] name RENAME [COLUMN] column TO new_column ALTER TABLE name RENAME ... ... <看更多>

Rename Tbl2 (the new one) to Tbl1. This will give you much better performance. The reason is, altering the column on table containing data, will ... ... <看更多>