SQL PHP HTML ASP JavaScript articles and free scripts to download

SQL SELECT Command

Select command is used to collect date from the table. We will discuss more on this by adding more commands to this select command. If you have not created the tables then please go to sql introduction page to use the sql commands to create the tables and fill the table with some records ( data ).

Now your table with some data is ready. We will apply select command to our table ( name student ) and fetch all the records

SELECT * FROM `student`

id name class mark
1 John Deo Four 75
2 Max Ruin Three 85
3 Arnold Three 55
4 Krish Star Four 60
5 John Mike Four 60
6 Alex John Four 55

That's all to get all the records from the table student. We have not placed any restriction here and asked for all the fields with all the records. Now if we want to restrict our results and get only name field from the table.

SELECT name FROM `student`

This will return only name field from the table. We can ask for more fields and all field names we have to separate by comma. We can include as many field names we want from a table.

SELECT name, class FROM `student`

Now we will go for bit more and restrict the number of records we are getting. We are interested say in only 3 records. Our command should return 3 records only. We will use SQL limit command. This will take two parameters. One is the starting point and other is number of records required. Say we are interested in 3 records starting from beginning. Our command will be

SELECT * FROM `student` LIMIT 0,3


This command with LIMIT command will return us 3 records starting from 0 ( or first ) record. This is very important when we use this command with ORDER BY command. Now let us try to list all the students who have come in first 3 ranks. We are required to list here 3 records who have mark more than the others. The top 3 students we want to display in order of first, second and third. The order we can display are in by default in ascending order but we require the listing should return in descending order so we will get the highest ranked student at the top. Before that let us start with a simple example of ORDER BY command.

SELECT * FROM `student` ORDER BY mark

This will display the records of students in the order of lowest mark to highest mark We will change it to display in reverse order so it will display highest mark at the top and lowest mark at the bottom.

SELECT * FROM `student` ORDER BY `mark` DESC

With the addition of command DESC we can change the order of display to keep the highest mark at the top of the list and lowest mark at the bottom of the list. Now let us add the LIMIT command to display only the top 3 records. We already have the list in the order of highest mark to lowest mark so by just limiting the number of records to 3 will give our required top three student records.

SELECT * FROM `student` ORDER BY `mark` DESC LIMIT 0,3

id name class
2 Max Ruin Three 85
1 John Deo Four 75
4 Krish Star Four 60
This is the SQL query which will display top three students  based on the mark they scored. In the next section we will use sql WHERE clause to restrict or filter the records.

Google+

raju11-04-2013
How to get ( select ) data from more than one table ?
Post Comment This is for short comments only. Use the forum for more discussions.
Name
Email( not to be displayed)Privacy Policy
1+2=This is to prevent automatic submission by spammers. Please enter the result of the sum as asked



Join Our Email List
Email:  
For Email Newsletters you can trust

HTML . MySQL. PHP. JavaScript. ASP. Photoshop. Articles. FORUM Contact us

©2000-2014 plus2net.com All rights reserved worldwide Privacy Policy Disclaimer