PHP mysql_result()函数使用方法

1. Introduction

The mysql_result() function in PHP is used to retrieve data from a MySQL database. It is a simple function that takes in a result set returned by a MySQL query and returns a single value.

2. Syntax

The syntax for the mysql_result() function is as follows:

$value = mysql_result($result_set, $row, $column);

2.1 Parameters

$result_set - the result set returned by the MySQL query

$row - the row number (starting from 0) to retrieve data from

$column - the column number (starting from 0) to retrieve data from

2.2 Return Value

The mysql_result() function returns the value from the specified row and column in the result set. If the specified row or column does not exist, the function returns false.

3. Example

Let's say we have a table called "students" with the following columns:

id

name

age

major

We can retrieve the name of the student with id=1 using the following PHP code:

$query = "SELECT name FROM students WHERE id = 1";

$result = mysql_query($query);
$name = mysql_result($result, 0, 0);

This code first executes a MySQL query to retrieve the name of the student with id=1. It then passes the result set to the mysql_result() function to retrieve the first (and only) value in the result set. Finally, it stores the name in the $name variable.

4. Conclusion

The mysql_result() function is a simple and useful function for retrieving data from a MySQL database. It is especially useful when you only need to retrieve a single value from a result set. However, it is important to note that the function has been deprecated in PHP 5.5.0 and removed in PHP 7.0.0, so you should use an alternative method (such as mysqli or PDO) if you are using a newer version of PHP.