MySQLi - Sorting Results-alljchome-开发者的教程家园

MySQLi Tutorial

MySQL

MySQLi Useful Resources

Selected Reading

MySQLi - Sorting Results

We have seen the SQL SELECT command to fetch data from a MySQL table. When you select rows, the MySQL server is free to return them in any order, unless you instruct it otherwise by saying how to sort the result. But, you sort a result set by adding an ORDER BY clause that names the column or columns which you want to sort.

Syntax

The following code block is a generic SQL syntax of the SELECT command along with the ORDER BY clause to sort the data from a MySQL table.


SELECT field1, field2,...fieldN table_name1, table_name2...
ORDER BY field1, [field2...] [ASC [DESC]]

You can sort the returned result on any field, if that field is being psted out.

You can sort the result on more than one field.

You can use the keyword ASC or DESC to get result in ascending or descending order. By default, it s the ascending order.

You can use the WHERE...LIKE clause in the usual way to put a condition.

Using ORDER BY clause at the Command Prompt

This will use the SQL SELECT command with the ORDER BY clause to fetch data from the MySQL table – tutorials_tbl.

Example

Try out the following example, which returns the result in an ascending order.


root@host# mysql -u root -p password;
Enter password:*******
mysql> use TUTORIALS;
Database changed
mysql> SELECT * from tutorials_tbl ORDER BY tutorial_author ASC
+-------------+----------------+-----------------+-----------------+
| tutorial_id | tutorial_title | tutorial_author | submission_date |
+-------------+----------------+-----------------+-----------------+
|      2      |  Learn MySQL   |     Abdul S     |    2007-05-24   |   
|      1      |   Learn PHP    |    John Poul    |    2007-05-24   |   
|      3      | JAVA Tutorial  |     Sanjay      |    2007-05-06   |   
+-------------+----------------+-----------------+-----------------+
3 rows in set (0.42 sec)

mysql>

Verify all the author names that are psted out in the ascending order.

Using ORDER BY clause inside a PHP Script

PHP uses mysqp query() or mysql_query() function to get sorted records from a MySQL table. This function takes two parameters and returns TRUE on success or FALSE on failure.

Syntax


$mysqp→query($sql,$resultmode)

Sr.No.	Parameter & Description
1	$sql Required - SQL query to get sorted records from a table.
2	$resultmode Optional - Either the constant MYSQLI_USE_RESULT or MYSQLI_STORE_RESULT depending on the desired behavior. By default, MYSQLI_STORE_RESULT is used.

Sr.No.

Parameter & Description

$sql

Required - SQL query to get sorted records from a table.

$resultmode

Optional - Either the constant MYSQLI_USE_RESULT or MYSQLI_STORE_RESULT depending on the desired behavior. By default, MYSQLI_STORE_RESULT is used.

Example

Try the following example to get sorted records from a table −

Copy and paste the following example as mysql_example.php −


<html>
   <head>
      <title>Sorting MySQL Table records</title>
   </head>
   <body>
      <?php
         $dbhost =  localhost ;
         $dbuser =  root ;
         $dbpass =  root@123 ;
         $dbname =  TUTORIALS ;
         $mysqp = new mysqp($dbhost, $dbuser, $dbpass, $dbname);
         
         if($mysqp→connect_errno ) {
            printf("Connect failed: %s<br />", $mysqp→connect_error);
            exit();
         }
         printf( Connected successfully.<br /> );
   
         $sql = "SELECT tutorial_id, tutorial_title, tutorial_author, submission_date FROM tutorials_tbl order by tutorial_title asc";
         $result = $mysqp→query($sql);
           
         if ($result→num_rows > 0) {
            while($row = $result→fetch_assoc()) {
               printf("Id: %s, Title: %s, Author: %s, Date: %d <br />", 
                  $row["tutorial_id"], 
                  $row["tutorial_title"], 
                  $row["tutorial_author"],
                  $row["submission_date"]);               
            }
         } else {
            printf( No record found.<br /> );
         }
         mysqp_free_result($result);
         $mysqp→close();
      ?>
   </body>
</html>

Output

Access the mysql_example.php deployed on apache web server and verify the output.


Connected successfully.
Id: 5, Title: Apache Tutorial, Author: Suresh, Date: 2021
Id: 2, Title: HTML Tutorial, Author: Mahesh, Date: 2021
Id: 1, Title: MySQL Tutorial, Author: Mahesh, Date: 2021
Id: 3, Title: PHP Tutorial, Author: Mahesh, Date: 2021

MySQLi - Sorting Results

Syntax

Using ORDER BY clause at the Command Prompt

Example

Using ORDER BY clause inside a PHP Script

Syntax

Example

Output

友情链接