SQL Facts SQL Commands Categories  SQL stands for Structured Query Language Data Query Language (DQL) “QL is ponounced seuel  SELECT - Retrieve data from table(s)   SQL is declarative language Data Manipulation Language (DML)

 SQL is used to access & manipulate data in databases  INSERT - Insert data into db table Top SQL DBs are MS SQL Server, Oracle, DB2, and MySQL UPDATE - Update data in db table    DELETE - Delete data from table Database Definitions Data Definition Language (DDL) RDBMS (Relational Database Management System)  – CREATE - Create db object (table, view, etc.) Software that stores and manipulates data arranged in  ALTER - Modify db object (table, view, etc.) relational database tables.   DROP - Delete db object (table, view, etc.)  Table – A set of data arranged in columns and rows. The columns represent characteristics of stored data and the Data Control Language (DCL)

rows represent actual data entries.  GRANT - Assign privilege  REVOKE - remove privilege

How to select data from a table How to insert data in a table

SELECT INSERT INTO

FROM () VALUES ()

WHERE

Example:

Example: INSERT INTO Orders

SELECT FirstName, LastName, OrderDate (FirstName, LastName, OrderDate) VALUES FROM Orders WHERE OrderDate > '10/10/2010' ('John', 'Smith', '10/10/2010')

How to update data in a table How to delete data from a table

UPDATE

DELETE FROM SET = , = , … WHERE

WHERE

Example:

Example: DELETE FROM Orders

UPDATE Orders WHERE OrderDate < '10/10/2010' SET FirstName = 'John', LastName = 'Who' WHERE LastName='Wo'

How to group data and use aggregates How to order data

SELECT , () SELECT FROM

FROM WHERE WHERE GROUP BY ORDER BY

Example: Example:

SELECT LastName, SUM(OrderValue) SELECT FirstName, LastName, OrderDate FROM Orders FROM Orders WHERE OrderDate > '10/10/2010' WHERE OrderDate > '10/10/2010' GROUP BY LastName ORDER BY OrderDate

How to select data from more than one table Using UNION

SELECT SELECT FROM FROM JOIN UNION ON . = . SELECT FROM

Example: Example:

SELECT Orders.LastName, Countries.CountryName SELECT FirstName, LastName FROM Orders2010 FROM Orders JOIN Countries ON UNION Orders.CountryID = Countries.ID SELECT FirstName, LastName FROM Orders2011

CREATE TABLE CREATE TABLE

CREATE TABLE Orders ( Column1 DataType, ( FirstName CHAR(100), Column2 DataType, LastName CHAR(100), Column3 DataType, OrderDate DATE, …. ) OrderValue Currency ) © http://www.SQL-Tutorial.net