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Call stored procedures from Django

This article explains how to create and call SQL Server stored procedures from Django applications using the mssql-django backend.

Create a stored procedure in a migration

Use migrations.RunSQL to create a stored procedure as part of your Django migration workflow:

from django.db import migrations

class Migration(migrations.Migration):

    dependencies = [
        ("myapp", "0001_initial"),
    ]

    operations = [
        migrations.RunSQL(
            sql="""
                CREATE PROCEDURE GetProductsByCategory
                    @CategoryName NVARCHAR(100)
                AS
                BEGIN
                    SET NOCOUNT ON;
                    SELECT id, name, price
                    FROM myapp_product
                    WHERE category = @CategoryName;
                END;
            """,
            reverse_sql="DROP PROCEDURE IF EXISTS GetProductsByCategory;",
        ),
    ]

Apply the migration:

python manage.py migrate

Call a stored procedure

Use Django's connection.cursor() to call stored procedures with raw SQL:

from django.db import connection

def get_products_by_category(category_name):
    with connection.cursor() as cursor:
        cursor.execute("EXECUTE GetProductsByCategory @CategoryName = %s;", [category_name])
        results = cursor.fetchall()
    return results

Call a stored procedure with multiple parameters

Pass multiple parameters as a list:

from django.db import connection

def search_products(category_name, min_price):
    with connection.cursor() as cursor:
        cursor.execute(
            "EXECUTE SearchProducts @CategoryName = %s, @MinPrice = %s;",
            [category_name, min_price],
        )
        results = cursor.fetchall()
    return results

Read column names from results

Access column names from cursor.description:

from django.db import connection

def get_products_as_dicts(category_name):
    with connection.cursor() as cursor:
        cursor.execute("EXECUTE GetProductsByCategory @CategoryName = %s;", [category_name])
        columns = [col[0] for col in cursor.description]
        results = [dict(zip(columns, row)) for row in cursor.fetchall()]
    return results

Handle multiple result sets

Some stored procedures return multiple result sets. Use cursor.nextset() to navigate between them:

from django.db import connection

def get_dashboard_data():
    with connection.cursor() as cursor:
        cursor.execute("EXECUTE GetDashboardData;")

        # First result set
        products = cursor.fetchall()

        # Move to second result set
        cursor.nextset()
        categories = cursor.fetchall()

    return products, categories

Wrap in a Django manager

Encapsulate stored procedure calls in a custom manager for cleaner code:

from django.db import connection, models

class ProductManager(models.Manager):
    def by_category(self, category_name):
        with connection.cursor() as cursor:
            cursor.execute(
                "EXECUTE GetProductsByCategory @CategoryName = %s;",
                [category_name],
            )
            columns = [col[0] for col in cursor.description]
            return [dict(zip(columns, row)) for row in cursor.fetchall()]

class Product(models.Model):
    name = models.CharField(max_length=100)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    category = models.CharField(max_length=100)

    objects = ProductManager()

Usage:

products = Product.objects.by_category("Electronics")

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