In ANSI SQL, the backslash character (\) is the escape character. To search for data that begins with the string \abc , the WHERE clause must use an escape character as follows: ... where col1 = '\\abc';
Use braces to escape a string of characters or symbols. Everything within a set of braces in considered part of the escape sequence. When you use braces to escape a single character, the escaped character becomes a separate token in the query. Use the backslash character to escape a single character or symbol.
The simplest method to escape single quotes in SQL is to use two single quotes. For example, if you wanted to show the value O'Reilly, you would use two quotes in the middle instead of one. The single quote is the escape character in Oracle, SQL Server, MySQL, and PostgreSQL.
In particular, the \n escape sequence represents the newline character. A \n in a printf format string tells awk to start printing output at the beginning of a newline.
You can escape quotation like this:
select 'it''s escaped'
result will be
it's escaped
To escape '
you simly need to put another before: ''
As the second answer shows it's possible to escape single quote like this:
select 'it''s escaped'
result will be
it's escaped
If you're concatenating SQL into a VARCHAR to execute (i.e. dynamic SQL), then I'd recommend parameterising the SQL. This has the benefit of helping guard against SQL injection plus means you don't have to worry about escaping quotes like this (which you do by doubling up the quotes).
e.g. instead of doing
DECLARE @SQL NVARCHAR(1000)
SET @SQL = 'SELECT * FROM MyTable WHERE Field1 = ''AAA'''
EXECUTE(@SQL)
try this:
DECLARE @SQL NVARCHAR(1000)
SET @SQL = 'SELECT * FROM MyTable WHERE Field1 = @Field1'
EXECUTE sp_executesql @SQL, N'@Field1 VARCHAR(10)', 'AAA'
You can define your escape character, but you can only use it with a LIKE
clause.
Example:
SELECT columns FROM table
WHERE column LIKE '%\%%' ESCAPE '\'
Here it will search for %
in whole string and this is how one can use ESCAPE
identifier in SQL Server
.
You need to just replace '
with ''
inside your string
SELECT colA, colB, colC
FROM tableD
WHERE colA = 'John''s Mobile'
You can also use REPLACE(@name, '''', '''''')
if generating the SQL dynamically
If you want to escape inside a like statement then you need to use the ESCAPE syntax
It's also worth mentioning that you're leaving yourself open to SQL injection attacks if you don't consider it. More info at Google or: http://it.toolbox.com/wiki/index.php/How_do_I_escape_single_quotes_in_SQL_queries%3F
Escaping quotes in MSSQL is done by a double quote, so a ''
or a ""
will produce one escaped '
and "
, respectively.
If you want to escape user input in a variable you can do like below within SQL
Set @userinput = replace(@userinput,'''','''''')
The @userinput will be now escaped with an extra single quote for every occurance of a quote
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