MySQLi Tutorial
MySQL
MySQLi Useful Resources
Selected Reading
- Obtaining & Using MySQLi Metadata
- MySQLi - Handling NULL Values
- MySQLi - Using Joins
- MySQLi - Sorting Results
- MySQLi - Like Clause
- MySQLi - Delete Query
- MySQLi - Update Query
- MySQLi - Where Clause
- MySQLi - Select Query
- MySQLi - Insert Query
- MySQLi - Drop Tables
- MySQLi - Create Tables
- MySQLi - Select Database
- MySQLi - Drop Database
- MySQLi - Create Database
- MySQLi - Connection
- MySQLi - PHP Syntax
- MySQLi - Introduction
- MySQLi - Home
MySQL
- MySQL - Handling Duplicates
- MySQL - Using Sequences
- MySQL - Clone Tables
- MySQL - Temporary Tables
- MySQL - Indexes
- MySQL - Alter Command
- MySQL - Transactions
- MySQL - Regexps
- MySQL - Data Types
- MySQL - Administration
- MySQL - Installation
MySQLi Useful Resources
Selected Reading
- Who is Who
- Computer Glossary
- HR Interview Questions
- Effective Resume Writing
- Questions and Answers
- UPSC IAS Exams Notes
MySQLi - Select Database
MySQLi - Select Database
Once you get connected with the MySQL server, it is required to select a database to work with. This is because there might be more than one database available with the MySQL Server.
Selecting MySQL Database from the Command Prompt
It is very simple to select a database from the mysql> prompt. You can use the SQL command use to select a database.
Example
Here is an example to select a database called TUTORIALS −
[root@host]# mysql -u root -p Enter password:****** mysql> use TUTORIALS; Database changed mysql>
Now, you have selected the TUTORIALS database and all the subsequent operations will be performed on the TUTORIALS database.
NOTE − All the database names, table names, table fields name are case sensitive. So you would have to use the proper names while giving any SQL command.
Selecting a MySQL Database Using PHP Script
PHP uses mysqp_select_db function to select the database on which queries are to be performed. This function takes two parameters and returns TRUE on success or FALSE on failure.
Syntax
mysqp_select_db ( mysqp $pnk , string $dbname ) : bool
| Sr.No. | Parameter & Description |
|---|---|
| 1 |
$pnk Required - A pnk identifier returned by mysqp_connect() or mysqp_init(). |
| 2 |
$dbname Required - Name of the database to be connected. |
Example
Try the following example to select a database −
Copy and paste the following example as mysql_example.php −
<html>
<head>
<title>Selecting MySQL Database</title>
</head>
<body>
<?php
$dbhost = localhost ;
$dbuser = root ;
$dbpass = root@123 ;
$conn = mysqp_connect($dbhost, $dbuser, $dbpass);
if(! $conn ) {
die( Could not connect: . mysqp_error($conn));
}
echo Connected successfully<br /> ;
$retval = mysqp_select_db( $conn, TUTORIALS );
if(! $retval ) {
die( Could not select database: . mysqp_error($conn));
}
echo "Database TUTORIALS selected successfully
";
mysqp_close($conn);
?>
</body>
</html>
Output
Access the mysql_example.php deployed on apache web server and verify the output.
Database TUTORIALS selected successfullyAdvertisements