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Khóa học miễn phí MySQLi – Like Clause nhận dự án làm có lương

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MySQLi – Like Clause

We have seen the SQL SELECT command to fetch data from the MySQL table. We can also use a conditional clause called as the WHERE clause to select the required records.

A WHERE clause with the ‘equal to’ sign (=) works fine where we want to do an exact match. Like if “tutorial_author = ”Sanjay””. But there may be a requirement where we want to filter out all the results where tutorial_author name should contain “jay”. This can be handled using SQL LIKE Clause along with the WHERE clause.

If the SQL LIKE clause is used along with the % character, then it will work like a meta character (*) as in UNIX, while listing out all the files or directories at the command prompt. Without a % character, the LIKE clause is very same as the equal to sign along with the WHERE clause.

Syntax

The following code block has a generic SQL syntax of the SELECT command along with the LIKE clause to fetch data from a MySQL table.

SELECT field1, field2,...fieldN table_name1, table_name2...
WHERE field1 LIKE condition1 [AND [OR]] filed2 = ''somevalue''

  • You can specify any condition using the WHERE clause.

  • You can use the LIKE clause along with the WHERE clause.

  • You can use the LIKE clause in place of the equals to sign.

  • When LIKE is used along with % sign then it will work like a meta character search.

  • You can specify more than one condition using AND or OR operators.

  • A WHERE…LIKE clause can be used along with DELETE or UPDATE SQL command also to specify a condition.

Using the LIKE clause at the Command Prompt

This will use the SQL SELECT command with the WHERE…LIKE clause to fetch the selected data from the MySQL table – tutorials_tbl.

Example

The following example will return all the records from the tutorials_tbl table for which the author name ends with jay −

root@host# mysql -u root -p password;
Enter password:*******
mysql> use TUTORIALS;
Database changed
mysql> SELECT * from tutorials_tbl 
   → WHERE tutorial_author LIKE ''%jay
+-------------+----------------+-----------------+-----------------+
| tutorial_id | tutorial_title | tutorial_author | submission_date |
+-------------+----------------+-----------------+-----------------+
|      3      |  JAVA Tutorial |     Sanjay      |    2007-05-21   |   
+-------------+----------------+-----------------+-----------------+
1 rows in set (0.01 sec)

mysql>

Using LIKE clause inside PHP Script

PHP uses mysqli query() or mysql_query() function to select records in a MySQL table using Like clause. This function takes two parameters and returns TRUE on success or FALSE on failure.

Syntax

$mysqli→query($sql,$resultmode)

Sr.No. Parameter & Description
1

$sql

Required – SQL query to select records in a MySQL table using Like Clause.
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.

Example

Try the following example to select a record using like clause in a table −

Copy and paste the following example as mysql_example.php −

<html>
   <head>
      <title>Using Like Clause</title>
   </head>
   <body>
      <?php
         $dbhost = ''localhost
         $dbuser = ''root
         $dbpass = ''root@123
         $dbname = ''TUTORIALS
         $mysqli = new mysqli($dbhost, $dbuser, $dbpass, $dbname);
         
         if($mysqli→connect_errno ) {
            printf("Connect failed: %s<br />", $mysqli→connect_error);
            exit();
         }
         printf(''Connected successfully.<br />'');
   
         $sql = ''SELECT tutorial_id, tutorial_title, tutorial_author, submission_date FROM tutorials_tbl where tutorial_author like "Mah%"
		 
         $result = $mysqli→query($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"],
                  $row["submission_date"]);               
            }
         } else {
            printf(''No record found.<br />'');
         }
         mysqli_free_result($result);
         $mysqli→close();
      ?>
   </body>
</html>

Output

Access the mysql_example.php deployed on apache web server and verify the output. Here we”ve entered multiple records in the table before running the select script.

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

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