| title | Row Objects in mssql-python |
|---|---|
| description | Learn how to work with Row objects returned by cursor fetch operations in the mssql-python driver. |
| author | dlevy-msft-sql |
| ms.author | dlevy |
| ms.date | 07/16/2026 |
| ms.service | sql |
| ms.subservice | connectivity |
| ms.topic | reference |
| ai-usage | ai-assisted |
The mssql-python driver returns row data as Row objects from fetch operations. These objects provide flexible access patterns:
- Attribute access (
row.ColumnName) is the most readable choice for named columns. Use it when your query has a known, stable column list. - String key access (
row['ColumnName']) provides dictionary-style access to columns by name, useful when you need programmatic column lookup or when column names contain spaces or special characters. - Index access (
row[0]) is useful for dynamic queries where column names aren't known at development time, or when processingSELECT *results. - Tuple unpacking (
a, b, c = row) is the most concise choice for loop bodies with a small, fixed number of columns.
Access column values directly by name:
import mssql_python
conn = mssql_python.connect(connection_string)
cursor = conn.cursor()
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID = 1")
row = cursor.fetchone()
print(row.ProductID) # 1
print(row.Name) # 'Adjustable Race'
print(row.ListPrice) # 0.00Column name access is case-sensitive and matches the column names returned by SQL Server. If your database uses inconsistent casing, use SQL AS aliases to normalize names, or enable the lowercase module setting (see Module configuration):
cursor.execute("SELECT FirstName, LastName, EmailPromotion FROM Person.Person WHERE BusinessEntityID < 10")
row = cursor.fetchone()
print(row.FirstName) # Works
print(row.LastName) # Works
print(row.EmailPromotion) # Works
print(row.firstname) # AttributeError - wrong caseUse SQL aliases to create friendly attribute names:
cursor.execute("""
SELECT
p.ProductID,
p.Name,
c.Name AS Category
FROM Production.Product p
JOIN Production.ProductSubcategory c ON p.ProductSubcategoryID = c.ProductSubcategoryID
WHERE p.ProductSubcategoryID IS NOT NULL
""")
for row in cursor:
print(f"{row.Name} ({row.Category})")Access values by zero-based column index:
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID < 5")
row = cursor.fetchone()
print(row[0]) # ProductID
print(row[1]) # Name
print(row[2]) # ListPriceThe driver supports Python-style negative indexing:
cursor.execute("""
SELECT Demo.A, Demo.B, Demo.C, Demo.D
FROM (VALUES (1, 2, 3, 4)) AS Demo(A, B, C, D)
""")
row = cursor.fetchone()
print(row[-1]) # Last column (D)
print(row[-2]) # Second to last (C)Access column values by name using dictionary-style syntax:
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID = 1")
row = cursor.fetchone()
print(row['ProductID']) # 1
print(row['Name']) # 'Adjustable Race'
print(row['ListPrice']) # Decimal('0.00')This is useful when column names contain spaces or special characters, or when you need to access columns programmatically:
column_name = 'ListPrice'
value = row[column_name] # Programmatic column accessExtract multiple values using slices:
cursor.execute("""
SELECT Demo.A, Demo.B, Demo.C, Demo.D, Demo.E
FROM (VALUES (1, 2, 3, 4, 5)) AS Demo(A, B, C, D, E)
""")
row = cursor.fetchone()
print(row[1:4]) # Columns B, C, D (indices 1, 2, 3)
print(row[:2]) # First two columns (A, B)
print(row[2:]) # From C to endUnpack row values directly into variables:
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID < 10")
for product_id, name, price in cursor:
print(f"#{product_id}: {name} - ${price}")Use * to capture remaining values:
cursor.execute("""
SELECT TOP 2 ProductID, Name, ProductNumber, Color, Size, Weight
FROM Production.Product
WHERE ProductNumber IS NOT NULL
ORDER BY ProductID
""")
for product_id, name, *rest in cursor:
print(f"{product_id}: {name}, extra columns: {rest}")Work with row dimensions and iterate through column values:
Use len() to get the number of columns in a row:
cursor.execute("SELECT * FROM Production.Product WHERE ProductID < 5")
row = cursor.fetchone()
print(len(row)) # Number of columnsLoop through column values in order:
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID < 5")
row = cursor.fetchone()
for value in row:
print(value)Use hasattr() to test for the presence of a column name:
# Use hasattr to check for column name
if hasattr(row, 'DiscountPrice'):
print(f"Discount: {row.DiscountPrice}")
else:
print("No discount available")Row objects can be converted to standard Python types for integration with other libraries and APIs:
Convert a row to a tuple using the tuple() constructor:
cursor.execute("SELECT ProductID, Name FROM Production.Product WHERE ProductID = 1")
row = cursor.fetchone()
row_tuple = tuple(row)
print(row_tuple) # (1, 'Adjustable Race')Convert a row to a list using the list() constructor:
row_list = list(row)
print(row_list) # [1, 'Adjustable Race']Convert a row to a dictionary when you need to serialize it to JSON, pass it to a template engine, or merge it with other data. Build the dictionary from cursor.description and row values:
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID = 1")
row = cursor.fetchone()
# Create dict from description and values
columns = [col[0] for col in cursor.description]
row_dict = dict(zip(columns, row))
print(row_dict) # {'ProductID': 1, 'Name': 'Adjustable Race', 'ListPrice': Decimal('0.00')}Create a reusable helper function to convert all fetched rows to dictionaries:
def rows_to_dicts(cursor):
"""Convert fetched rows to list of dictionaries."""
columns = [col[0] for col in cursor.description]
return [dict(zip(columns, row)) for row in cursor.fetchall()]
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID < 10")
products = rows_to_dicts(cursor)
for p in products:
print(p['Name'])The driver returns NULL values as Python None:
cursor.execute("SELECT FirstName, MiddleName, LastName FROM Person.Person WHERE BusinessEntityID = 1")
row = cursor.fetchone()
if row.MiddleName is None:
full_name = f"{row.FirstName} {row.LastName}"
else:
full_name = f"{row.FirstName} {row.MiddleName} {row.LastName}"Access column metadata alongside row data:
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID < 5")
# Column information
for col in cursor.description:
print(f"Name: {col[0]}, Type: {col[1]}")
# Fetch with metadata
row = cursor.fetchone()
for i, col in enumerate(cursor.description):
print(f"{col[0]}: {row[i]}")Here are practical patterns for working with Row objects in real-world applications:
Process rows using attribute access for readable, maintainable code:
def process_orders(conn):
cursor = conn.cursor()
cursor.execute("""
SELECT SalesOrderID, CustomerID, OrderDate, TotalDue
FROM Sales.SalesOrderHeader
WHERE Status = 5
""")
for order in cursor:
print(f"Order #{order.SalesOrderID}")
print(f" Customer: {order.CustomerID}")
print(f" Date: {order.OrderDate}")
print(f" Total: ${order.TotalDue:.2f}")For applications with a domain model, map rows to data classes or typed objects. This mapping gives you IDE autocompletion, type checking, and a clear boundary between database rows and application logic.
from dataclasses import dataclass
from datetime import date
from decimal import Decimal
@dataclass
class Product:
id: int
name: str
price: Decimal
created: date
def get_products(conn) -> list[Product]:
cursor = conn.cursor()
cursor.execute("SELECT ProductID, Name, ListPrice, SellStartDate FROM Production.Product WHERE ProductID < 10")
return [
Product(
id=row.ProductID,
name=row.Name,
price=row.ListPrice,
created=row.SellStartDate
)
for row in cursor
]Serialize Row objects to JSON with custom type handling for datetime and Decimal values:
import json
from datetime import date, datetime
from decimal import Decimal
def json_serializer(obj):
"""Custom serializer for non-JSON types."""
if isinstance(obj, (date, datetime)):
return obj.isoformat()
if isinstance(obj, Decimal):
return float(obj)
raise TypeError(f"Type {type(obj)} not serializable")
def export_to_json(cursor, filename):
columns = [col[0] for col in cursor.description]
rows = [dict(zip(columns, row)) for row in cursor.fetchall()]
with open(filename, 'w') as f:
json.dump(rows, f, default=json_serializer, indent=2)
cursor.execute("SELECT ProductID, Name, ListPrice FROM Production.Product WHERE ProductID < 10")
export_to_json(cursor, "products.json")Group rows by a column value and collect them into a dictionary for analysis or display:
from collections import defaultdict
cursor.execute("""
SELECT c.Name AS CategoryName, p.Name AS ProductName, p.ListPrice
FROM Production.Product p
JOIN Production.ProductSubcategory c ON p.ProductSubcategoryID = c.ProductSubcategoryID
WHERE p.ProductSubcategoryID IS NOT NULL
ORDER BY c.Name
""")
products_by_category = defaultdict(list)
for row in cursor:
products_by_category[row.CategoryName].append({
'name': row.ProductName,
'price': row.ListPrice
})
for category, products in products_by_category.items():
print(f"\n{category}:")
for p in products:
print(f" - {p['name']}: ${p['price']}")