WHERE子句提供了一种在操作使用完全匹配时检索数据的方法.在需要具有共享特征的多个结果的情况下， LIKE 子句适用于广泛的模式匹配.
LIKE子句测试模式匹配，返回true或false.用于比较的模式接受以下通配符:"％"，它匹配字符数(0或更多);和"_"，匹配单个字符. "_"通配符仅匹配其集合中的字符，这意味着它在使用另一个集合时将忽略拉丁字符.默认情况下，匹配不区分大小写需要区分大小写的其他设置.
一个NOT LIKE子句允许测试相反的条件，就像 not 运算符一样.
如果语句表达式或模式计算为NULL，则结果为NULL.
查看下面给出的常规LIKE子句语法 :
SELECT field, field2,... FROM table_name, table_name2,... WHERE field LIKE condition
在命令提示符或PHP脚本中使用LIKE子句.
在命令提示符下，只需使用标准命令 :
root@host# mysql -u root -p password; Enter password:******* mysql> use TUTORIALS; Database changed mysql> SELECT * from products_tbl WHERE product_manufacturer LIKE 'XYZ%'; +-------------+----------------+----------------------+ | ID_number | Nomenclature | product_manufacturer | +-------------+----------------+----------------------+ | 12345 | Orbitron 4000 | XYZ Corp | +-------------+----------------+----------------------+ | 12346 | Orbitron 3000 | XYZ Corp | +-------------+----------------+----------------------+ | 12347 | Orbitron 1000 | XYZ Corp | +-------------+----------------+----------------------+
使用 mysql_query( )使用LIKE子句的语句中的函数
<?php
$dbhost = 'localhost:3036';
$dbuser = 'root';
$dbpass = 'rootpassword';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
if(! $conn ) {
die('Could not connect: ' . mysql_error());
}
$sql = 'SELECT product_id, product_name, product_manufacturer, ship_date
FROM products_tbl WHERE product_manufacturer LIKE "xyz%"';
mysql_select_db('PRODUCTS');
$retval = mysql_query( $sql, $conn );
if(! $retval ) {
die('Could not get data: ' . mysql_error());
}
while($row = mysql_fetch_array($retval, MYSQL_ASSOC)) {
echo "Product ID:{$row['product_id']} <br> ".
"Name: {$row['product_name']} <br> ".
"Manufacturer: {$row['product_manufacturer']} <br> ".
"Ship Date: {$row['ship_date']} <br> ".
"--------------------------------<br>";
}
echo "Fetched data successfully\n";
mysql_close($conn);
?>成功检索数据后，您将看到以下输出 :
Product ID: 12345 Nomenclature: Orbitron 4000 Manufacturer: XYZ Corp Ship Date: 01/01/17 ---------------------------------------------- Product ID: 12346 Nomenclature: Orbitron 3000 Manufacturer: XYZ Corp Ship Date: 01/02/17 ---------------------------------------------- Product ID: 12347 Nomenclature: Orbitron 1000 Manufacturer: XYZ Corp Ship Date: 01/02/17 ---------------------------------------------- mysql> Fetched data successfully
