SQL - Cheat Sheet

This is a basic SQL cheat sheet that covers the most commonly used SQL statements and functions.

info

Keep in mind that different SQL databases have slightly different syntax and features, so consult the documentation for the specific database you are using for more information.

SELECT Statement

SELECT columns from a table

SELECT column1, column2, ...
FROM table_name;

SELECT DISTINCT unique values from a column

SELECT DISTINCT column_name
FROM table_name;

WHERE clause to filter rows

SELECT column1, column2, ...
FROM table_name
WHERE condition;

ORDER BY clause to sort the result set

SELECT column1, column2, ...
FROM table_name
ORDER BY column1 [ASC | DESC];

LIMIT clause to limit the number of rows returned

SELECT column1, column2, ...
FROM table_name
LIMIT number_of_rows;

GROUP BY and HAVING Clause

GROUP BY clause to group rows by one or more columns

SELECT column1, aggregate_function(column2)
FROM table_name
GROUP BY column1;

HAVING clause to filter groups based on a aggregate function

SELECT column1, aggregate_function(column2)
FROM table_name
GROUP BY column1
HAVING aggregate_function(column2) operator value;

INSERT Statement

INSERT INTO statement to insert new rows into a table

INSERT INTO table_name (column1, column2, ...)
VALUES (value1, value2, ...);

UPDATE Statement

UPDATE statement to modify existing rows in a table

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

DELETE Statement

DELETE FROM table_name
WHERE condition;

JOIN

JOIN clause to combine rows from two or more tables based on a related column between them.

SELECT column1, column2, ...
FROM table1
JOIN table2
ON table1.column = table2.column;

LEFT JOIN returns all rows from the left table, and the matched rows from the right table

SELECT column1, column2, ...
FROM table1
LEFT JOIN table2
ON table1.column = table2.column;

RIGHT JOIN returns all rows from the right table, and the matched rows from the left table

SELECT column1, column2, ...
FROM table1
RIGHT JOIN table2
ON table1.column = table2.column;

CREATE

CREATE DATABASE statement to create a new database

CREATE DATABASE database_name;

CREATE TABLE statement to create a new table

CREATE TABLE table_name (
    column1 datatype constraint,
    column2 datatype constraint,
    ...
);

ALTER

ALTER DATABASE statement to modify the current database

ALTER DATABASE database_name
SET new_property = value;

ALTER TABLE statement to add a new column to a table

ALTER TABLE table_name
ADD COLUMN column_name datatype constraint;

ALTER TABLE statement to modify the datatype of a column

ALTER TABLE table_name
MODIFY COLUMN column_name new_datatype constraint;

ALTER TABLE statement to rename a table

ALTER TABLE table_name
RENAME TO new_table_name;

INDEX

CREATE INDEX statement to create an index on a table

CREATE INDEX index_name
ON table_name (column1, column2, ...);

DROP INDEX statement to delete an index

DROP INDEX index_name;

VIEW

CREATE VIEW statement to create a view

CREATE VIEW view_name AS
SELECT column1, column2, ...
FROM table_name
WHERE condition;

DROP VIEW statement to delete a view

DROP VIEW view_name;

Function

COUNT() function returns the number of rows

SELECT COUNT(column_name)
FROM table_name;

SUM() function returns the total value of a numeric column

SELECT SUM(column_name)
FROM table_name;

AVG() function returns the average value of a numeric column

SELECT AVG(column_name)
FROM table_name;

MAX() function returns the maximum value of a column

SELECT MAX(column_name)
FROM table_name;

MIN() function returns the minimum value of a column

SELECT MIN(column_name)
FROM table_name;