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STRING_ESCAPE (Transact-SQL)

  • Article
  • 06/01/2023

Applies to: SQL Server 2016 (13.x) and later Azure SQL Database Azure SQL Managed Instance

Escapes special characters in texts and returns text with escaped characters. STRING_ESCAPE is a deterministic function, introduced in SQL Server 2016.

Transact-SQL syntax conventions

Syntax

STRING_ESCAPE( text , type )

Arguments

text
Is a nvarchar expression representing the object that should be escaped.

type
Escaping rules that will be applied. Currently the value supported is 'json'.

Return Types

nvarchar(max) text with escaped special and control characters. Currently STRING_ESCAPE can only escape JSON special characters shown in the following tables.

Special character Encoded sequence
Quotation mark (") \"
Reverse solidus (\) \\
Solidus (/) \/
Backspace \b
Form feed \f
New line \n
Carriage return \r
Horizontal tab \t
Control character Encoded sequence
CHAR(0) \u0000
CHAR(1) \u0001
... ...
CHAR(31) \u001f

Remarks

Examples

A. Escape text according to the JSON formatting rules

The following query escapes special characters using JSON rules and returns escaped text.

SELECT STRING_ESCAPE('\   /  
\\    "     ', 'json') AS escapedText;

Here's the result set.

escapedText  
-------------------------------------------------------------  
\\\t\/\n\\\\\t\"\t

B. Format JSON object

The following query creates JSON text from number and string variables, and escapes any special JSON character in variables.

SET @json = FORMATMESSAGE('{ "id": %d,"name": "%s", "surname": "%s" }',
    17, STRING_ESCAPE(@name,'json'), STRING_ESCAPE(@surname,'json') );

See Also