the sql select command is used to fetch data from the mysql database. you can use this command at mysql> prompt as well as in any script like php.

syntax

here is generic sql syntax of select command to fetch data from the mysql table −

select field1, field2,...fieldn 
from table_name1, table_name2...
[where clause]
[offset m ][limit n]

you can use one or more tables separated by comma to include various conditions using a where clause, but the where clause is an optional part of the select command.
you can fetch one or more fields in a single select command.
you can specify star (*) in place of fields. in this case, select will return all the fields.
you can specify any condition using the where clause.
you can specify an offset using offset from where select will start returning records. by default, the offset starts at zero.
you can limit the number of returns using the limit attribute.

fetching data from a command prompt

this will use sql select command to fetch data from the mysql table tutorials_tbl.

example

the following example will return all the records from the tutorials_tbl table −

root@host# mysql -u root -p password;
enter password:*******
mysql> use tutorials;
database changed
mysql> select * from tutorials_tbl 
+-------------+----------------+-----------------+-----------------+
| tutorial_id | tutorial_title | tutorial_author | submission_date |
+-------------+----------------+-----------------+-----------------+
|           1 | learn php      | john poul       | 2007-05-21      |
|           2 | learn mysql    | abdul s         | 2007-05-21      |
|           3 | java tutorial  | sanjay          | 2007-05-21      |
+-------------+----------------+-----------------+-----------------+
3 rows in set (0.01 sec)

mysql>

fetching data using a php script

php uses mysqli query() or mysql_query() function to select records from a mysql table. this function takes two parameters and returns true on success or false on failure.

syntax

$mysqli→query($sql,$resultmode)

sr.no.

parameter & description

$sql

required - sql query to select records from a mysql 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 select a record from a table −

copy and paste the following example as mysql_example.php −

<html>
   <head>
      <title>creating mysql table</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";
		 
         $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
id: 4, title: java tutorial, author: mahesh, date: 2021
id: 5, title: apache tutorial, author: suresh, date: 2021

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