JSON_VALUE


The JSON_VALUE function in SQL Server is a powerful tool that allows users to extract a scalar value from a JSON string. This function is particularly useful when dealing with JSON data within SQL Server databases. Let's delve into a detailed explanation of its use case with a practical example.

Syntax of JSON_VALUE Function:
The syntax of the JSON_VALUE function is as follows:

    JSON_VALUE (expression, path)


expression: The JSON string from which to extract the value.
path: The JSON path that specifies the location of the value to be extracted.

Example Scenario:
Suppose we have a table named Employee in our SQL Server database that stores employee information in JSON format. Each row contains a JSON object representing details such as name, age, and department. Here is a sample JSON structure stored in the Employee table:

    {
    "name": "John Doe",
    "age": 30,
    "department": "IT"
    }


Example 1- Query Using JSON_VALUE:
Now, let's say we want to extract the value of the name field from the JSON data stored in the Employee table. We can achieve this using the JSON_VALUE function as shown below:

    SELECT JSON_VALUE(Employee.JsonColumn, '$.name') AS EmployeeName
    FROM Employee


In this query:

Employee.JsonColumn represents the column in the Employee table that stores the JSON data.
'$ .name' is the JSON path that specifies the name field within the JSON object.
Output:
Upon executing the query, the result will be a single column named EmployeeName containing the extracted value of the name field from the JSON data.

Example 2- Query Using JSON_VALUE:

    DECLARE @json NVARCHAR(MAX) = '{"name": "John", "age": 30, "city": "New York"}';

    SELECT JSON_VALUE(@json, '$.name') AS PersonName;


In this example:

  • We declare a variable @json containing a JSON string with key-value pairs.
  • We use the JSON_VALUE function to extract the value associated with the key 'name' from the JSON string.
  • The JSON path '$' specifies the root of the JSON object, and 'name' specifies the key whose value we want to extract.
  • The result of this query will be the value 'John', which is the value associated with the key 'name' in the JSON string.
  • Remember, when using the JSON_VALUE function, ensure that the JSON path provided is correct and points to the desired value within the JSON string.
The JSON_VALUE function in SQL Server is a powerful tool that allows users to extract a scalar value from a JSON string. This function is particularly useful when dealing with JSON data within SQL Server databases. Let's delve into a detailed explanation of its use case with a practical example.

Syntax of JSON_VALUE Function:
The syntax of the JSON_VALUE function is as follows:

    JSON_VALUE (expression, path)


expression: The JSON string from which to extract the value.
path: The JSON path that specifies the location of the value to be extracted.

Example Scenario:
Suppose we have a table named Employee in our SQL Server database that stores employee information in JSON format. Each row contains a JSON object representing details such as name, age, and department. Here is a sample JSON structure stored in the Employee table:

    {
    "name": "John Doe",
    "age": 30,
    "department": "IT"
    }


Example 1- Query Using JSON_VALUE:
Now, let's say we want to extract the value of the name field from the JSON data stored in the Employee table. We can achieve this using the JSON_VALUE function as shown below:

    SELECT JSON_VALUE(Employee.JsonColumn, '$.name') AS EmployeeName
    FROM Employee


In this query:

Employee.JsonColumn represents the column in the Employee table that stores the JSON data.
'$ .name' is the JSON path that specifies the name field within the JSON object.
Output:
Upon executing the query, the result will be a single column named EmployeeName containing the extracted value of the name field from the JSON data.

Example 2- Query Using JSON_VALUE:

    DECLARE @json NVARCHAR(MAX) = '{"name": "John", "age": 30, "city": "New York"}';

    SELECT JSON_VALUE(@json, '$.name') AS PersonName;


In this example:

  • We declare a variable @json containing a JSON string with key-value pairs.
  • We use the JSON_VALUE function to extract the value associated with the key 'name' from the JSON string.
  • The JSON path '$' specifies the root of the JSON object, and 'name' specifies the key whose value we want to extract.
  • The result of this query will be the value 'John', which is the value associated with the key 'name' in the JSON string.
  • Remember, when using the JSON_VALUE function, ensure that the JSON path provided is correct and points to the desired value within the JSON string.

Talk to us?

Post your blog