MariaDB Like子句
MariaDB Like子句
WHERE子句提供了一种完全匹配的功能,在需要模糊匹配的情况下,LIKE子句更加合适。
LIKE子句测试匹配模式,返回true或false。 模式接受以下通配符:“%”、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,这意味着当使用另一个集合时,它将忽略拉丁字符。默认情况下,匹配不区分大小写,需要额外的区分大小写设置。
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评估为空,则结果为空。
下面是LIKE子句的基本语法:
SELECT field, field2,... FROM table_name, table_name2,... WHERE field LIKE condition
可以在命令提示符下或PHP脚本中使用LIKE子句。
命令提示符
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 | +-------------+----------------+----------------------+
PHP使用LIKE子句
PHP在mysql_query() 执行LIKE子句的语句:
<?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