# SQL Cheat Sheet

SQL (Structured Query Language) in one page (credit/original) nb not (originally) SQLite-specific.
Table of contents: Database Manipulation (CREATE, DROP DATABASE), Table Manipulation (CREATE, ALTER, DROP TABLE, Data Types), Index Manipulation (CREATE, DROP INDEX), Data Manipulation (INSERT, UPDATE, DELETE, TRUNCATE TABLE), Select (SELECT, FROM, WHERE, ORDER BY, GROUP BY, HAVING, Operators, Aggregate functions), Alias, JOIN, UNION, SELECT INTO/IN, CREATE VIEW.
Database Manipulation
CREATE DATABASE database_name | Create a database [nb: not SQLite, use sqlite3_open] | CREATE DATABASE My_First_Database
DROP DATABASE database_name | Delete a database [nb: not SQLite, use delete_file] | DROP DATABASE My_First_Database
Table Manipulation
CREATE TABLE " table_name" (" column_1" " data_type_for_column_1", " column_2" " data_type_for_column_2", ... ) | Create a table in a database. | CREATE TABLE Person (LastName varchar, FirstName varchar, Address varchar, Age int)
Data Types (see also Datatypes In SQLite Version 3)
Data Type | Description
--- | ---
integer(size) | Hold integers only. The maximum number of digits are specified in parenthesis.
int(size)
smallint(size)
tinyint(size)
decimal(size,d) | Hold numbers with fractions. The maximum number of digits are specified in "size". The maximum number of digits to the right of the decimal is specified in "d".
numeric(size,d)
char(size) | Holds a fixed length string (can contain letters, numbers, and special characters). The fixed size is specified in parenthesis.
varchar(size) | Holds a variable length string (can contain letters, numbers, and special characters). The maximum size is specified in parenthesis.
date(yyyymmdd) | Holds a date
ALTER TABLE table_name ADD column_name datatype | Add columns in an existing table. | ALTER TABLE Person ADD Sex char(6)
ALTER TABLE table_name DROP column_name datatype | Delete columns in an existing table. [nb: SQLite does not implement DROP COLUMN.] | ALTER TABLE Person DROP Sex char(6)
DROP TABLE table_name | Delete a table. | DROP TABLE Person
Index Manipulation
CREATE INDEX index_name ON table_name ( column_name_1, column_name_2, ...) | Create a simple index. | CREATE INDEX PersonIndex ON Person (LastName, FirstName)
CREATE UNIQUE INDEX index_name ON table_name ( column_name_1, column_name_2, ...) | Create a unique index. | CREATE UNIQUE INDEX PersonIndex ON Person (LastName DESC)
DROP INDEX table_name.index_name | Delete an index. | DROP INDEX Person.PersonIndex
Data Manipulation
INSERT INTO table_name VALUES ( value_1, value_2,....) | Insert new rows into a table. | INSERT INTO Persons VALUES('Hussein', 'Saddam', 'White House')
INSERT INTO table_name ( column1, column2,...) VALUES ( value_1, value_2,....) | INSERT INTO Persons (LastName, FirstName, Address) VALUES('Hussein', 'Saddam', 'White House')
UPDATE table_name SET column_name_1 = new_value_1, column_name_2 = new_value_2 WHERE column_name = some_value | Update one or several columns in rows. | UPDATE Person SET Address = 'ups' WHERE LastName = 'Hussein'
DELETE FROM table_name WHERE column_name = some_value | Delete rows in a table. | DELETE FROM Person WHERE LastName = 'Hussein'
TRUNCATE TABLE table_name | Deletes the data inside the table. [nb: not SQLite (use "DELETE FROM table_name;")] | TRUNCATE TABLE Person
SELECT
SELECT column_name(s) FROM table_name | Select data from a table. | SELECT LastName, FirstName FROM Persons
SELECT * FROM table_name | Select all data from a table. | SELECT * FROM Persons
SELECT DISTINCT column_name(s) FROM table_name | Select only distinct (different) data from a table. | SELECT DISTINCT LastName, FirstName FROM Persons
SELECT column_name(s) FROM table_name WHERE column operator value AND column operator value OR column operator value AND (... OR ...) ... | Select only certain data from a table. | SELECT * FROM Persons WHERE sex='female'
Operators
Operator | Description
--- | ---
= | Equal
<> | Not equal
> | Greater than
< | Less than
>= | Greater than or equal
<= | Less than or equal
BETWEEN | Between an inclusive range
LIKE | Search for a pattern. A "%" sign can be used to define wildcards (missing letters in the pattern) both before and after the pattern.
| SELECT * FROM Persons WHERE Year>1970
SELECT * FROM Persons WHERE FirstName='Saddam' AND LastName='Hussein'
SELECT * FROM Persons WHERE FirstName='Saddam' OR LastName='Hussein'
SELECT * FROM Persons WHERE (FirstName='Tove' OR FirstName='Stephen') AND LastName='Svendson'
SELECT * FROM Persons WHERE FirstName LIKE 'O%'
SELECT * FROM Persons WHERE FirstName LIKE '%a'
SELECT * FROM Persons WHERE FirstName LIKE '%la%'
SELECT column_name(s) FROM table_name WHERE column_name IN ( value1, value2, ...) | The IN operator may be used if you know the exact value you want to return for at least one of the columns. | SELECT * FROM Persons WHERE LastName IN ('Hansen','Pettersen')
SELECT column_name(s) FROM table_name ORDER BY row_1, row_2 DESC, row_3 ASC, ... | Select data from a table with sort the rows. Note: ASC (ascend) is a alphabetical and numerical order (optional) DESC (descend) is a reverse alphabetical and numerical order | SELECT * FROM Persons ORDER BY LastName
SELECT FirstName, LastName FROM Persons ORDER BY LastName DESC
SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC, OrderNumber ASC
SELECT column_1, ..., SUM( group_column_name) FROM table_name GROUP BY group_column_name | GROUP BY... was added to SQL because aggregate functions (like SUM) return the aggregate of all column values every time they are called, and without the GROUP BY function it was impossible to find the sum for each individual group of column values. | SELECT Company, SUM(Amount) FROM Sales GROUP BY Company
Some aggregate functions
Function | Description
--- | ---
AVG(column) | Returns the average value of a column
COUNT(column) | Returns the number of rows (without a NULL value) of a column
MAX(column) | Returns the highest value of a column
MIN(column) | Returns the lowest value of a column
SUM(column) | Returns the total sum of a column
SELECT column_1, ..., SUM( group_column_name) FROM table_name GROUP BY group_column_name HAVING SUM( group_column_name) condition value | HAVING... was added to SQL because the WHERE keyword could not be used against aggregate functions (like SUM), and without HAVING... it would be impossible to test for result conditions. | SELECT Company, SUM(Amount) FROM Sales GROUP BY Company HAVING SUM(Amount)>10000
Alias
SELECT column_name AS column_alias FROM table_name | Column name alias | SELECT LastName AS Family, FirstName AS Name FROM Persons
SELECT table_alias.column_name FROM table_name AS table_alias | Table name alias | SELECT LastName, FirstName FROM Persons AS Employees
JOIN
SELECT column_1_name, column_2_name, ... FROM first_table_name INNER JOIN second_table_name ON first_table_name.keyfield = second_table_name.foreign_keyfield | The INNER JOIN returns all rows from both tables where there is a match. If there are rows in first table that do not have matches in second table, those rows will not be listed. | SELECT Employees.Name, Orders.Product FROM Employees INNER JOIN Orders ON Employees.Employee_ID=Orders.Employee_ID
SELECT column_1_name, column_2_name, ... FROM first_table_name LEFT JOIN second_table_name ON first_table_name.keyfield = second_table_name.foreign_keyfield | The LEFT JOIN returns all the rows from the first table, even if there are no matches in the second table. If there are rows in first table that do not have matches in second table, those rows also will be listed. | SELECT Employees.Name, Orders.Product FROM Employees LEFT JOIN Orders ON Employees.Employee_ID=Orders.Employee_ID
SELECT column_1_name, column_2_name, ... FROM first_table_name RIGHT JOIN second_table_name ON first_table_name.keyfield = second_table_name.foreign_keyfield | The RIGHT JOIN returns all the rows from the second table, even if there are no matches in the first table. If there had been any rows in second table that did not have matches in first table, those rows also would have been listed. [nb: SQLite does not implement RIGHT OUTER JOIN or FULL OUTER JOIN.] | SELECT Employees.Name, Orders.Product FROM Employees RIGHT JOIN Orders ON Employees.Employee_ID=Orders.Employee_ID
UNION
SQL_Statement_1 UNION SQL_Statement_2 | Select all different values from SQL_Statement_1 and SQL_Statement_2 | SELECT E_Name FROM Employees_Norway UNION SELECT E_Name FROM Employees_USA
SQL_Statement_1 UNION ALL SQL_Statement_2 | Select all values from SQL_Statement_1 and SQL_Statement_2 | SELECT E_Name FROM Employees_Norway UNION SELECT E_Name FROM Employees_USA
SELECT INTO/IN
SELECT column_name(s) INTO new_table_name FROM source_table_name WHERE query | Select data from table(S) and insert it into another table. | SELECT * INTO Persons_backup FROM Persons
SELECT column_name(s) IN external_database_name FROM source_table_name WHERE query | Select data from table(S) and insert it in another database. | SELECT Persons.* INTO Persons IN 'Backup.db' FROM Persons WHERE City='Sandnes'
CREATE VIEW
CREATE VIEW view_name AS SELECT column_name(s) FROM table_name WHERE condition | Create a virtual table based on the result-set of a SELECT statement. [nb: SQLite views are read-only.] | CREATE VIEW [Current Product List] AS SELECT ProductID, ProductName FROM Products WHERE Discontinued=No