Otu esi ajụ MySQL ka? Ojiji nke nkwupụta dị na nchekwa data MySQL

Kedu otu esi eme ajụjụ LIKE na MySQL ? Kedu iwu ojiji nke nkwupụta LIKE na nchekwa data MySQL ?

MySQL dị ka nkeji okwu

Anyị maara iji iwu SQL SELECT ịgụ data na MySQL, anyị nwere ike iji okwu WHERE dị na nkwupụta SELECT iji nweta ndekọ ndị akọwapụtara.

Nkebi okwu WHERE nwere ike iji akara nha nhata (=) tọọ ọnọdụ maka iweta data, dịka "chenweiliang_author = 'chenweiliang.com'".

Mana mgbe ụfọdụ, anyị kwesịrị ịnweta ndekọ niile nke ubi chenweiliang_author nwere mkpụrụedemede "COM", mgbe ahụ anyị kwesịrị iji nkebiokwu SQL DỊ KA dị na nkebiokwu WHERE.

Nkebi ahịrịokwu SQL LIKE na-eji mkpụrụedemede pasentị akara % iji nọchite anya mkpụrụedemede ọ bụla, nke yiri akara mmuke * na UNIX ma ọ bụ okwu nkịtị.

Ọ bụrụ na ejirighị pasentị akara % mee ihe , nkebi ahịrịokwu LIKE nwere otu mmetụta ahụ dịka nhata akara = .

ụtọ asụsụ

Ihe na-esonụ bụ nchịkọta izugbe nke nkwupụta SQL SELECT iji gụọ data sitere na tebụl data site na iji nkebiokwu dị ka:

SELECT field1, field2,...fieldN 
FROM table_name
WHERE field1 LIKE condition1 [AND [OR]] filed2 = 'somevalue'

• Ị nwere ike ịkọwa ọnọdụ ọ bụla na nkebi ahịrịokwu WHERE.
• Ị nwere ike iji nkebiokwu dị ka na nkebiokwu WHERE.
• Ị nwere ike iji nkebiokwu dị ka akara akara nhata =.
• A na-ejikọta LIKE na ya % Ejikọta ọnụ, yiri ọchụchọ meta agwa.
• Ị nwere ike ezipụta otu ọnọdụ ma ọ bụ karịa site na iji AND ma ọ bụ OR.
• Ị nwere ike iji WHERE...Dịka nkebi ahịrịokwu dị na ehichapụ ma ọ bụ kwalite iwu iji kọwapụta ọnọdụ.

Iji okwu dị ka nke dị na iwu ozugbo

N'okpuru ebe a, anyị ga-eji WHERE...Dịka nkebi ahịrịokwu dị na SQL SELECT iji gụọ data sitere na MySQL data table chenweiliang_tbl.

ihe atụ

Ndepụta ihe ndekọ niile sitere na tebụl chenweiliang_tbl nke na-ejedebe na "COM" na ngalaba chenweiliang_author :

mysql> use chenweiliang;
Database changed
mysql> SELECT * from chenweiliang_tbl WHERE chenweiliang_author LIKE '%COM';
+-----------+---------------+---------------+-----------------+
| chenweiliang_id | chenweiliang_title | chenweiliang_author | submission_date |
+-----------+---------------+---------------+-----------------+
| 3 | 学习 Java | chenweiliang.com | 2015-05-01 |
| 4 | 学习 Python | chenweiliang.com | 2016-03-06 |
+-----------+---------------+---------------+-----------------+
2 rows in set (0.01 sec)

Iji ahịrịokwu LIKE na script PHP

Ị nwere ike iji PHP ọrụ mysqli_query() na otu iwu SQL SELECT na a WHERE...Dị ka nkebiokwu iji nweta data.

A na-eji ọrụ a iji mezuo iwu SQL wee wepụta data maka ajụjụ niile site na ọrụ PHP mysqli_fetch_assoc().

Mana ọ bụrụ na ọ bụ nkwupụta SQL na-eji WHERE...Dị ka nkebiokwu dị na DELETE ma ọ bụ UPDATE, ọ dịghị mkpa iji mysqli_fetch_array() ọrụ.

ihe atụ

Nke a bụ otu anyị si eji script PHP gụọ ndekọ niile na-agwụ na COM na mpaghara chenweiliang_author dị na tebụl chenweiliang_tbl:

<?
php
$dbhost = 'localhost:3306'; // mysql服务器主机地址
$dbuser = 'root'; // mysql用户名
$dbpass = '123456'; // mysql用户名密码
$conn = mysqli_connect($dbhost, $dbuser, $dbpass);
if(! $conn )
{
 die('连接失败: ' . mysqli_error($conn));
}
// 设置编码，防止中文乱码
mysqli_query($conn , "set names utf8");
 
$sql = 'SELECT chenweiliang_id, chenweiliang_title, 
 chenweiliang_author, submission_date
 FROM chenweiliang_tbl
 WHERE chenweiliang_author LIKE "%COM"';
 
mysqli_select_db( $conn, 'chenweiliang' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
 die('无法读取数据: ' . mysqli_error($conn));
}
echo '<h2>陈沩亮博客 mysqli_fetch_array 测试<h2>';
echo '<table border="1"><tr><td>教程 ID</td><td>标题</td><td>作者</td><td>提交日期</td></tr>';
while($row = mysqli_fetch_array($retval, MYSQL_ASSOC))
{
 echo "<tr><td> {$row['chenweiliang_id']}</td> ".
 "<td>{$row['chenweiliang_title']} </td> ".
 "<td>{$row['chenweiliang_author']} </td> ".
 "<td>{$row['submission_date']} </td> ".
 "</tr>";
}
echo '</table>';
mysqli_close($conn);
?>