ISJSON (Transact-SQL)

**APPLIES TO:** SQL Server (starting with 2016) Azure SQL Database Azure SQL Data Warehouse Parallel Data Warehouse

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)