SQL Syntax

## SQL Basic

SQL HOME SQL Intro SQL Syntax SQL SELECT SQL SELECT DISTINCT SQL WHERE SQL AND & OR SQL ORDER BY SQL INSERT INTO SQL UPDATE SQL DELETE SQL Injection

## SQL Advanced

SQL SELECT TOP SQL LIKE SQL Wildcards SQL IN SQL BETWEEN SQL Aliases SQL Joins SQL INNER JOIN SQL LEFT JOIN SQL RIGHT JOIN SQL FULL JOIN SQL UNION SQL SELECT INTO SQL INSERT INTO SELECT SQL CREATE DB SQL CREATE TABLE SQL Constraints SQL NOT NULL SQL UNIQUE SQL PRIMARY KEY SQL FOREIGN KEY SQL CHECK SQL DEFAULT SQL CREATE INDEX SQL DROP SQL ALTER SQL Auto Increment SQL Views SQL Dates SQL NULL Values SQL NULL Functions SQL General Data Types SQL DB Data Types

## SQL Functions

SQL Functions SQL AVG() SQL COUNT() SQL FIRST() SQL LAST() SQL MAX() SQL MIN() SQL SUM() SQL GROUP BY SQL HAVING SQL UCASE() SQL LCASE() SQL MID() SQL LEN() SQL ROUND() SQL NOW() SQL FORMAT()
SQL Quick Ref SQL Hosting SQL Summary

## SQL Quiz

SQL Quiz

# SQL Syntax

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## Database Tables

A database most often contains one or more tables. Each table is identified by a name (e.g. "Customers" or "Orders"). Tables contain records (rows) with data.

In this tutorial we will use the well-known Northwind sample database (included in MS Access and MS SQL Server).

Below is a selection from the "Customers" table:

CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country
--- | --- | --- | --- | --- | --- | ---
1 | Alfreds Futterkiste | Maria Anders | Obere Str. 57 | Berlin | 12209 | Germany
2 | Ana Trujillo Emparedados y helados | Ana Trujillo | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico
3 | Antonio Moreno Taquería | Antonio Moreno | Mataderos 2312 | México D.F. | 05023 | Mexico
4 | Around the Horn | Thomas Hardy | 120 Hanover Sq. | London | WA1 1DP | UK
5 | Berglunds snabbköp | Christina Berglund | Berguvsvägen 8 | Luleå | S-958 22 | Sweden

The table above contains five records (one for each customer) and seven columns (CustomerID, CustomerName, ContactName, Address, City, PostalCode, and Country).

## SQL Statements

Most of the actions you need to perform on a database are done with SQL statements.

The following SQL statement selects all the records in the "Customers" table:

## Example

SELECT * FROM Customers;
Try it yourself »

In this tutorial we will teach you all about the different SQL statements.

## Keep in Mind That...

- SQL is NOT case sensitive: SELECT is the same as select

## Semicolon after SQL Statements?

Some database systems require a semicolon at the end of each SQL statement.

Semicolon is the standard way to separate each SQL statement in database systems that allow more than one SQL statement to be executed in the same call to the server.

In this tutorial, we will use semicolon at the end of each SQL statement.

## Some of The Most Important SQL Commands

- SELECT - extracts data from a database
- UPDATE - updates data in a database
- DELETE - deletes data from a database
- INSERT INTO - inserts new data into a database
- CREATE DATABASE - creates a new database
- ALTER DATABASE - modifies a database
- CREATE TABLE - creates a new table
- ALTER TABLE - modifies a table
- DROP TABLE - deletes a table
- CREATE INDEX - creates an index (search key)
- DROP INDEX - deletes an index

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