SQL IntroductionOnce your database and script installation is over then let us learn how to manage it.
SQL ( Structured Query Language ) is one of the important tool for the programmers. Sql is a part of the database management tool. There are many databases available from different venders. For web applications MSSQL, MySQL, MS Access are mostly used. Oracle is very popular among enterprise users. MySQL can be downloaded from mysql.net and it is free. Combination of PHP and MySQL is the most popular in the world today among all the web applications.
What is SQL
Sql is a common language to manage all the operations for a database. There are different SQL commands available to manage the database. You need not start reading or take training on all the commands at a time, you can use this site as a referance and read all our
free tutorials on SQL.
Now let us start with simple query to display all the records of a table. We will create a student table and fill with
some data. Don't worry on how to create the table. Use this SQL to create the
CREATE TABLE student ( id int(2) NOT NULL auto_increment, name varchar(50) NOT NULL default '',
class varchar(10) NOT NULL default '', mark int(3) NOT NULL default '0',
UNIQUE KEY id (id) ) TYPE=MyISAM;
This will create the table for us. We can see that there are three fields in the
table. One is id which is an auto increment and will take one unique number each
time one record is added to the table. Next field is name of 50 length, this
will store the student name. Next is class field of 10 length. Let us fill
the tables with some data. Here is the SQL to insert the data to the table. We
need not worry at this stage how this SQL works as we will discuss that in other
pages. You can just copy and paste this SQL code in your SQL window to
insert some records to the tables.
INSERT INTO student VALUES (1, 'John Deo', 'Four', 75);
INSERT INTO student VALUES (2, 'Max Ruin', 'Three', 85);
INSERT INTO student VALUES (3, 'Arnold', 'Three', 55);
INSERT INTO student VALUES (4, 'Krish Star', 'Four', 60);
INSERT INTO student VALUES (5, 'John Mike', 'Four', 60);
INSERT INTO student VALUES (6, 'Alex John', 'Five', 55);
This SQL code will insert six records to the
table. Now our table with data is ready. We will start learning
one SQL command now . Let us start with SELECT query.