To select only data that matches a specified criteria, add a WHERE clause to the SELECT statement.
在SELECT语句中加入一条WHERE子句可以选择仅与指定的要求相匹配的数据。

The WHERE clause
WHERE子句

To select only data that matches a specific criteria, add a WHERE clause to the SELECT statement.
在SELECT语句中加入一条WHERE子句可以选择仅与指定的要求相匹配的数据。

Syntax
语法

SELECT column FROM table
WHERE column operator value

The following operators can be used with the WHERE clause:
下面介绍WHERE子句中的操作符：

Note: SQL statements are not case sensitive. WHERE is the same as where.
注意：SQL语句是“字母大小写不敏感”的语句（它不区分字母的大小写），即：“WHERE”和“where”是一样的。

To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.
在PHP内创建数据库，我们需要在mysql_query()函数内使用上述语句。这个函数是用来发送MySQL数据库连接建立的请求和指令的。

Example
案例

The following example will select all rows from the "Person" table, where FirstName='Peter':
下面的例子：从“Person”表中选取FirstName=’Peter’的所有记录：

<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con) { die('Could not connect: ' . mysql_error()); }
mysql_select_db("my_db", $con);
$result = mysql_query("SELECT * FROM person
WHERE FirstName='Peter'");
while($row = mysql_fetch_array($result)) { echo $row['FirstName'] . " " . $row['LastName']; echo "<br />"; }
?>

The output of the code above will be:
上述代码将输出下面的结果：

Peter Griffin

MySQL 选择记录 MySQL Order By

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