What do brackets mean around column names in SQL Server?

Question

I added a field in SQL Server 2008 and it put the column name in brackets like this: [column2]. The other column names don't have brackets. What do the brackets mean?

The column is named macro-writer

Should I remove the minus sign and replace it with an underscore?

OP said `should i remove the minus sign and replace with underscore`. I would, if only so I don't have to use `[` and `]` everywhere! — KM., Aug 23 '10 at 20:26
It'll try to perform an arithmetic operation of `macro-writer` and will throw invalid column name exceptions for `macro` and `writer`. — Lukas G, Jun 15 '20 at 19:37

Ben Voigt · Answer 1 · 2015-01-02T16:45:07.923

33

Brackets are a form of quoting. It's only necessary if the column name contains spaces or punctuation or conflicts with a reserved word, but many wizards will just add the brackets for all field names to avoid the logic for deciding whether they are necessary.

edited Jan 02 '15 at 16:45

answered Aug 23 '10 at 20:13

Ben Voigt

277,958
43
419
720

score 27 · Accepted Answer · answered Aug 23 '10 at 20:15

27

Columns enclosed in square brackets are usually keywords or contain special characters or spaces.

What specific column name do you have enclosed in brackets?

answered Aug 23 '10 at 20:15

Bernard

7,908
2
36
33

[macro-writer] [macro-writer] – Alex Gordon Aug 23 '10 at 20:16
2

A hyphen is considered a special character. – Bernard Aug 23 '10 at 20:20
Yes, if the column name is INDEX then we need to use the [] to take out result. As INDEX is keyword – Build Succeeded Aug 20 '20 at 05:29

score 9 · Answer 3 · answered Aug 23 '10 at 20:16

9

Brackets allow you to use characters and names which are not allowed like spaces, reserved words and names starting with numbers

invalid my column, 1column col%umn, table

valid [my column], [1column], [col%umn], [table]

of course now you can become really creative :-)

create table [table]([table] varchar(20))

insert [table] values ('table')

select [table] from [table]

answered Aug 23 '10 at 20:16

SQLMenace

132,095
25
206
225

you will never have a table that has a mix of hebrew and thai font – Alex Gordon Aug 23 '10 at 20:42
1

Well, why not try it and see for yourself ;). Works on SQL 2005, 2008 create table [แสดงבוקרǣ] ( ID int not null ) – StuartLC Aug 25 '10 at 07:49
1

Select [table] from [table] where [table].[table] = 'table'. I love it!! – sMaN Dec 07 '15 at 23:39
I think that using such spaces and special characters for a column identifier could just be making unnecessary trouble for onesself elsewhere and generally avoid it. But what is the advantage of using `[my column]` over the more traditional SQL `"my column"`? – Ed Randall Nov 12 '21 at 06:57

score 4 · Answer 4 · edited May 23 '17 at 12:19

4

See related questions with answers:

I would recommend using underscore instead of dash in identifier names.

edited May 23 '17 at 12:19

Community

1
1

answered Aug 23 '10 at 20:19

Bill Karwin

538,548
86
673
828

Joe Stefanelli · Answer 5 · 2010-08-23T20:27:06.470

Brackets allow you to delimit names in SQL Server. This allows you to do such things as use keywords [count] or include spaces [my column name].

EDIT: For your follow up question, if this is a new column and there's no risk of breaking existing code, then I'd at least recommend replacing the hyphen with an underscore. Our own internal naming standards are to use PascalCase (e.g., MacroWriter) rather than underscores.

What do brackets mean around column names in SQL Server?

5 Answers5

Linked