Is it allowed to cast types in ANSI SQL like in postgres for example:
SELECT SUM( CAST(qnty AS int) - CAST(reserve AS int) ) AS sum
...
qnty and reserve are character columns.
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试):
问题:
回答1:
The CAST expression was added in SQL-92. You can see it for example in this draft.
