Passing JSON Values in SQL Select Statement

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In this article, we will explore how to pass JSON values in a SQL select statement using Python.

Introduction

With the increasing use of NoSQL databases and JSON data formats, it has become essential to learn how to manipulate and process JSON data in various programming languages. In this article, we will focus on passing JSON values in a SQL select statement using Python.

JSON Basics

Before diving into the details, let’s first understand what JSON is and its basic structure.

JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy to read and write. It is used for exchanging data between web servers, web applications, and mobile apps.

A JSON object consists of key-value pairs, where each key is a string and the value can be another string or an array. For example:

{
    "name": "John Doe",
    "age": 30,
    "address": {
        "street": "123 Main St",
        "city": "Anytown",
        "state": "CA"
    }
}

In this example, we have a JSON object with three key-value pairs. The first two are simple strings and integers, while the third is an array of objects.

Parsing JSON in Python

Python provides several libraries to parse and manipulate JSON data, including json. We will use the json library to load our JSON file.

Here’s an example of how to parse a JSON file using Python:

import json

with open('data.json') as f:
    data = json.load(f)

In this example, we open a file called data.json and use the json.load() function to load its contents into the data variable.

Passing JSON Values in SQL Select Statement

To pass JSON values in a SQL select statement, we can use the JSON_VALUE() function provided by Microsoft SQL Server. This function allows us to extract specific values from a JSON object.

Here’s an example of how to use the JSON_VALUE() function:

DECLARE @JSON VARCHAR(MAX) = '{"row_id": "1", "a": "600", "b": "hello", "date": "2017-07-01", "enabled": "TRUE", "id": "234"}';

SELECT * 
FROM xyz 
WHERE a = JSON_VALUE(@JSON, '$.a') 
  AND b = JSON_VALUE(@JSON, '$.b') 
  AND date = JSON_VALUE(@JSON, '$.date');

In this example, we declare a variable @JSON that contains our JSON data. We then use the JSON_VALUE() function to extract specific values from the JSON object and compare them with the corresponding columns in the xyz table.

Iterative Approach

The question asks how to pass each line of a JSON file in an iterative way. To achieve this, we can use a loop to iterate over each row in the JSON file and then execute the SQL select statement for each row.

Here’s an example of how to do this using Python:

import json

# Load JSON data from file
with open('data.json') as f:
    data = json.load(f)

# Loop through each row in the JSON data
for row in data:
    # Extract specific values from the JSON object
    row_id = JSON_VALUE(row, '$.row_id')
    a = JSON_VALUE(row, '$.a')
    b = JSON_VALUE(row, '$.b')
    date = JSON_VALUE(row, '$.date')

    # Execute SQL select statement for each row
    cursor.execute("SELECT * FROM xyz WHERE a = %s AND b = %s AND date = %s", (a, b, date))

In this example, we load the JSON data from a file and then use a loop to iterate over each row in the data. For each row, we extract specific values using the JSON_VALUE() function and then execute a SQL select statement with those values.

Conclusion

Passing JSON values in a SQL select statement can be achieved using various methods, including the JSON_VALUE() function provided by Microsoft SQL Server. In this article, we explored how to use Python to parse JSON data from a file and pass it into a SQL select statement using an iterative approach.

We hope that this article has helped you understand how to work with JSON data in Python and SQL Server.

Last modified on 2025-03-24