isjson-transact-sql.md

description	ISJSON (Transact-SQL)
title	ISJSON (Transact-SQL) | Microsoft Docs
ms.custom
ms.date	06/03/2020
ms.prod	sql
ms.technology	t-sql
ms.topic	language-reference
f1_keywords	ISJSON ISJSON_TSQL
helpviewer_keywords	ISJSON function JSON, validating
ms.assetid	c836f3d3-3e17-44ae-92bf-f341918896c3
author	jovanpop-msft
ms.author	jovanpop
ms.reviewer	jroth
monikerRange	= azuresqldb-current||= azure-sqldw-latest||>= sql-server-2016||>= sql-server-linux-2017

ISJSON (Transact-SQL)

[!INCLUDE sqlserver2016-asdb-asdbmi-asa]

Tests whether a string contains valid JSON.

Transact-SQL Syntax Conventions

Syntax

ISJSON ( expression )  

Arguments

expression
The string to test.

Return Value

Returns 1 if the string contains valid JSON; otherwise, returns 0. Returns null if expression is null.

Does not return errors.

Remarks

ISJSON does not check the uniqueness of keys at the same level.

Examples

Example 1

The following example runs a statement block conditionally if the parameter value @param contains valid JSON.

DECLARE @param <data type>
SET @param = <value>

IF (ISJSON(@param) > 0)  
BEGIN  
     -- Do something with the valid JSON value of @param.  
END

Example 2

The following example returns rows in which the column json_col contains valid JSON.

SELECT id, json_col
FROM tab1
WHERE ISJSON(json_col) > 0 

See Also

JSON Data (SQL Server)