问题描述
我有一个包含现有记录的现有数据库的副本.当我和表设计师一起玩时，注意到一些列名周围有 [].它们似乎都是任意类型的(float、datetime、netext、nvarchar 等)，并且列属性中没有任何内容可以去掉 [].我试图重命名删除 [] 但它在我退出编辑后立即重新出现.
I have a copy of an existing database with existing records. when i was playing around with the table designer and noticed some of the column names have [] around them. they all seem to be arbitrary typed (float, datetime, netext, nvarchar etc) and there is nothing in column properties that gets rid of the []. I tried to rename delete the [] but it reappaears as soon as I exit edit.
根据这篇帖子，它是xml 列的关键字列?但这些列都不是 xml 列.有人会向ms-sql新手解释这个目的吗?谢谢
according to this post, it is a keyword column for xml columns? but none of those columns are xml columns. Would someone kindly explain the purpose of this to a ms-sql newbie? thanks
推荐答案
方括号 [] 用于分隔标识符.如果列名是保留关键字或包含特殊字符(如空格或连字符)，则这是必需的.
The square brackets [] are used to delimit identifiers. This is necessary if the column name is a reserved keyword or contains special characters such as a space or hyphen.
有些用户甚至在不需要时也喜欢使用方括号.
Some users also like to use square brackets even when they are not necessary.
来自 MSDN:
分隔标识符
用双引号 (") 或括号 ([ ]) 括起来.符合标识符格式规则的标识符可能会或可能不会被分隔.
Are enclosed in double quotation marks (") or brackets ([ ]). Identifiers that comply with the rules for the format of identifiers may or may not be delimited.
SELECT *
FROM [TableX] --Delimiter is optional.
WHERE [KeyCol] = 124 --Delimiter is optional.
不符合所有标识符规则的标识符必须在 Transact-SQL 语句中分隔.
Identifiers that do not comply with all of the rules for identifiers must be delimited in a Transact-SQL statement.
SELECT *
FROM [My Table] --Identifier contains a space and uses a reserved keyword.
WHERE [order] = 10 --Identifier is a reserved keyword.
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