Ansi SQL type casting

问题

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.

回答1:

The CAST expression was added in SQL-92. You can see it for example in this draft.

来源：https://stackoverflow.com/questions/1530003/ansi-sql-type-casting