- Introduction To SQL
- SQL Syntax
- SQL SELECT Statement
- SQL SELECT DISTINCT Statement
- SQL WHERE Clause
- SQL AND, OR And NOT Operators
- SQL ORDER BY Keyword
- SQL INSERT INTO Statement
- SQL NULL Values
- SQL UPDATE Statement
- SQL DELETE Statement
- SQL TOP, LIMIT, FETCH FIRST Or ROWNUM Clause
- SQL MIN() And MAX() Functions
- SQL COUNT(), AVG() And SUM() Functions
- SQL LIKE Operator
- SQL Wildcards
- SQL IN Operator
- SQL BETWEEN Operator
- SQL Aliases
- SQL Joins
- SQL INNER JOIN Keyword
- SQL LEFT JOIN Keyword
- SQL RIGHT JOIN Keyword
- SQL FULL OUTER JOIN Keyword
- SQL Self Join
- SQL UNION Operator
- SQL GROUP BY Statement
- SQL HAVING Clause
- SQL EXISTS Operator
- SQL ANY And ALL Operators
- SQL SELECT INTO Statement
- SQL INSERT INTO SELECT Statement
- SQL CASE Statement
- SQL NULL Functions
- SQL Stored Procedures For SQL Server
- SQL Comments
- SQL Operators
- SQL CREATE DATABASE Statement
- SQL DROP DATABASE Statement
- SQL BACKUP DATABASE For SQL Server
- SQL CREATE TABLE Statement
- SQL DROP TABLE Statement
- SQL ALTER TABLE Statement
- SQL Constraints
- SQL NOT NULL Constraint
- SQL UNIQUE Constraint
- SQL PRIMARY KEY Constraint
- SQL FOREIGN KEY Constraint
- ALTER TABLE Orders DROP CONSTRAINT FK_PersonOrder;
- SQL DEFAULT Constraint
- SQL CREATE INDEX Statement
- SQL AUTO INCREMENT Field
- SQL Working With Dates
- SQL Views
- SQL Injection
- SQL Hosting
- SQL Data Types For MySQL, SQL Server, And MS Access
Introduction to SQL
What Is SQL?
- 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
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)
- To use a server-side scripting language, like PHP or ASP
- To use SQL to get the data you want
- 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:
Every table is broken up into smaller entities called fields. The fields in the Customers table consist of CustomerID, CustomerName, ContactName, Address, City, PostalCode and Country. A field is a column in a table that is designed to maintain specific information about every record in the 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.
A column is a vertical entity in a table that contains all information associated with a specific field in a table.