SELECT 中表名后的 SQL Server 额外文本

Question

我发现了一个 SQL 语句的作用是:

SELECT * FROM Users x

我的问题是:x 是什么？我以前从未见过这个。

谢谢。

Answer 1

x 是表 Users 的别名。

Using Table Aliases

The readability of a SELECT statement can be improved by giving a table an alias, also known as a correlation name or range variable. A table alias can be assigned either with or without the AS keyword:

SELECT * FROM Users x

SELECT * FROM Users AS x