📊 MS SQL Server Quick Reference

Common SQL queries and examples

1Select All Data from a Table

Retrieve all rows and columns from a table

SELECT * FROM TableName;

2Select Specific Columns

Retrieve only the columns you need

SELECT Column1, Column2 FROM TableName;

3Filter Rows (WHERE Clause)

Retrieve rows that match a specific condition

SELECT * FROM TableName WHERE Column1 = 'Value';

4Sort Results (ORDER BY)

Sort results in ascending or descending order

SELECT * FROM TableName ORDER BY Column1 ASC; -- or DESC

5Limit Results (TOP / OFFSET-FETCH)

Retrieve a limited number of rows

SELECT TOP 10 * FROM TableName;
Modern approach (SQL Server 2012+):
SELECT * FROM TableName ORDER BY Column1 OFFSET 0 ROWS FETCH NEXT 10 ROWS ONLY;

6Aggregate Functions

Calculate COUNT, SUM, AVG, MIN, MAX

SELECT COUNT(*) FROM TableName;
SELECT SUM(Column1) FROM TableName;
SELECT AVG(Column1) FROM TableName;

7GROUP BY

Group rows and apply aggregate functions

SELECT Column1, COUNT(*) FROM TableName GROUP BY Column1;

8JOINs

Combine data from multiple tables

INNER JOIN:
SELECT a.*, b.* FROM TableA a
INNER JOIN TableB b ON a.Key = b.Key;
LEFT JOIN:
SELECT a.*, b.* FROM TableA a
LEFT JOIN TableB b ON a.Key = b.Key;
RIGHT JOIN:
SELECT a.*, b.* FROM TableA a
RIGHT JOIN TableB b ON a.Key = b.Key;
FULL OUTER JOIN:
SELECT a.*, b.* FROM TableA a
FULL OUTER JOIN TableB b ON a.Key = b.Key;

9INSERT

Add new rows to a table

INSERT INTO TableName (Col1, Col2) VALUES ('Val1', 'Val2');

10UPDATE

Modify existing data in a table

UPDATE TableName SET Col1 = 'NewValue' WHERE Col2 = 'SomeValue';

11DELETE

Remove rows from a table

DELETE FROM TableName WHERE Col1 = 'Value';

12DISTINCT

Retrieve unique/distinct values

SELECT DISTINCT Column1 FROM TableName;

13IN and BETWEEN

Filter rows using multiple values or ranges

IN clause:
SELECT * FROM TableName WHERE Column1 IN ('Val1', 'Val2');
BETWEEN clause:
SELECT * FROM TableName WHERE Column2 BETWEEN 10 AND 20;

14LIKE (Wildcard Search)

Search for patterns in text

SELECT * FROM TableName WHERE Column1 LIKE '%pattern%';

15NULL Checks

Handle NULL values in queries

Check for NULL:
SELECT * FROM TableName WHERE Column1 IS NULL;
Check for NOT NULL:
SELECT * FROM TableName WHERE Column1 IS NOT NULL;

16HAVING (Filter Groups)

Filter grouped results with aggregate functions

SELECT Column1, COUNT(*) FROM TableName GROUP BY Column1 HAVING COUNT(*) > 5;

17CASE Statement

Conditional logic in queries

SELECT Column1,
    CASE WHEN Column2 > 100 THEN 'High' ELSE 'Low' END AS Category
FROM TableName;