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SQL•SQL Tutorial

Introduction to SQL

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Introduction to SQL

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What is SQL?

SQL is a standard language for accessing and manipulating databases.

SQL stands for Structured Query Language

SQL lets you access and manipulate databases

SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987

What Can SQL do?

SQL can execute queries against a database

SQL can retrieve data from a database

SQL can insert records in a database

SQL can update records in a database

SQL can delete records from a database

SQL can create new databases

SQL can create new tables in a database SQL can create stored procedures in a database

SQL can create views in a database

SQL can set permissions on tables, procedures, and views

Formula

SQL is a Standard - BUT....
Although SQL is an ANSI/ISO standard, there are different versions of the SQL language.

However, to be compliant with the ANSI standard, they all support at least the major commands (such as SELECT, UPDATE, DELETE, INSERT,

Where

) in a similar manner.

Note:

Most of the SQL database programs also have their own proprietary extensions in addition to the SQL standard!

Using SQL in Your Web Site

To build a web site that shows data from a database, you will need: An RDBMS database program (i.e. MS Access, SQL Server, MySQL)

Formula

To use a server - side scripting language, like PHP or ASP

To use SQL to get the data you want

Formula

To use HTML / CSS to style the page

Rdbms

RDBMS stands for Relational Database Management System. RDBMS is the basis for SQL, and for all modern database systems such as MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access. The data in RDBMS is stored in database objects called tables. A table is a collection of related data entries and it consists of columns and rows. Look at the "Customers" table:

Example

SELECT * FROM Customers;
The columns in the "Customers" table consist of CustomerID, CustomerName, ContactName, Address,

City, PostalCode and Country. A column is a vertical entity in a table. A record, also called a row, is each individual entry that exists in a table. For example, there are 91 records in the above Customers table. A record is a horizontal entity in a table.

Video: SQL Introduction

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