- MariaDB Tutorial
- MariaDB - Home
- MariaDB - Introduction
- MariaDB - Installation
- MariaDB - Administration
- MariaDB - PHP Syntax
- MariaDB - Connection
- MariaDB - Create Database
- MariaDB - Drop Database
- MariaDB - Select Database
- MariaDB - Data Types
- MariaDB - Create Tables
- MariaDB - Drop Tables
- MariaDB - Insert Query
- MariaDB - Select Query
- MariaDB - Where Clause
- MariaDB - Update Query
- MariaDB - Delete Query
- MariaDB - Like Clause
- MariaDB - Order By Clause
- MariaDB - Join
- MariaDB - Null Values
- MariaDB - Regular Expression
- MariaDB - Transactions
- MariaDB - Alter Command
- Indexes & Statistics Tables
- MariaDB - Temporary Tables
- MariaDB - Table Cloning
- MariaDB - Sequences
- MariaDB - Managing Duplicates
- MariaDB - SQL Injection Protection
- MariaDB - Backup Methods
- MariaDB - Backup Loading Methods
- MariaDB - Useful Functions
- MariaDB Useful Resources
- MariaDB - Quick Guide
- MariaDB - Useful Resources
- MariaDB - Discussion
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
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MariaDB - Select Database
After connecting to MariaDB, you must select a database to work with because many databases may exist. There are two ways to perform this task: from the command prompt or through a PHP script.
The Command Prompt
In choosing a database at the command prompt, simply utilize the SQL command ‘use’ −
[root@host]# mysql -u root -p Enter password:****** mysql> use PRODUCTS; Database changed mysql> SELECT database(); +-------------------------+ | Database | +-------------------------+ | PRODUCTS | +-------------------------+
Once you select a database, all subsequent commands will operate on the chosen database.
Note − All names (e.g., database, table, fields) are case sensitive. Ensure commands conform to the proper case.
PHP Select Database Script
PHP provides the mysql_select_db function for database selection. The function uses two parameters, one optional, and returns a value of “true” on successful selection, or false on failure.
Syntax
Review the following select database script syntax.
bool mysql_select_db( db_name, connection );
The description of the parameters is given below −
| S.No | Parameter & Description |
|---|---|
| 1 |
db_name This required parameter specifies the name of the database to use. |
| 2 |
connection When not specified, this optional parameter uses the most recent connection used. |
Try the following example code for selecting a database −
<html>
<head>
<title>Select a MariaDB Database</title>
</head>
<body>
<?php
$dbhost = 'localhost:3036';
$dbuser = 'guest1';
$dbpass = 'guest1a';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
if(! $conn ) {
die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_select_db( 'PRODUCTS' );
mysql_close($conn);
?>
</body>
</html>
On successful selection, you will see the following output −
mysql> Connected successfully