SQL server教程帮忙。


看后面的迈至科SQL教程：我在SQL　SERVER中执行了SELECT au_fname+" "+au_lname "author name" FROM authors代码，可系统提示我错误，错误信息为
Server: Msg 207, Level 16, State 3, Line 1
Invalid column name ' '.
这到底是怎么回事？？？如何在中间用一个逗号隔开？？？


以下是迈至科SQL教程：
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最后，你还可以使用连接运算符（它看起来像个加号）来连接两个字符型字段：

SELECT au_fname+" "+au_lname "author name" FROM authors

在这个例子中，你把字段au_fname和字段au_lname粘贴在一起，中间用一个逗号 隔开，并把查询结果的标题指定为author name。这个语句的执行结果将是这样的：

author names

…………………………………………………………

Johnson White

Marjorie Green

Cheryl Carson

Michael O’Leary

Dean Straight

…

(23 row(s) affected)

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