What is actually difference between [] and ' ' I'm asking because when I wrote the query I couldn't write
SELECT *
FROM 'Order Details'
WHERE OrderID = 11077
only possibility was
SELECT *
FROM [Order Details]
WHERE OrderID = 11077
but I can rename AS 'some name for column' why ' ' is sometimes wrong?
I'm using the Northwind sample database.
Single quotes denote a string literal, while square brackets ([..] - SQL Server/T-SQL specific) or double quotes (ANSI/ISO SQL standard) can enclose table (or column) names with spaces ("Order Items"), or names that start with a numeric (instead of a character - like [1998 Sales]).
So you should also be able to use this:
SELECT *
FROM "Order Details"
WHERE OrderID = 11077
Avoid spacess in table/column name. Brackets are required, when in table name have space, Sqlserver consider it 2 different word.
When we use reserved word or string as a column / table name, we required square brackets.
Delimited identifiers
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.
Please see the same question's answer:
What is the use of the square brackets [] in sql statements?
This is example
select [first Name], [last name] from tablename where [last name]='name'
[] is used to add a space between two words in column like in above [last name]
and
'' is used for a strings or execute the query as a string like 'name' and also using in full query in parameter like
declare @perameter1
set @perameter= ('select * from tablename where name like =''name''')
