Me pehea te patai ki a MySQL?

mysql Me pehea te patai penei?mysql pātengi raraungaHainamana te whakamahi korero

MySQL LIKE rara

E mohio ana matou ki te whakamahi i te whakahau SQL SELECT ki te panui raraunga i MySQL, a ka taea e matou te whakamahi i te WHERE rara i roto i te korero SELECT ki te tiki i nga rekoata kua tohua.

Ka taea te whakamahi i te tohu rite ki te rara WHERE = Hei whakarite i nga tikanga mo te whiwhi raraunga, penei "chenweiliang_author = 'chenweiliang.com'".

Engari i etahi wa ka hiahia tatou ki te tiki i nga rekoata katoa kei roto i te mara chenweiliang_author nga tohu "COM", katahi me whakamahi te SQL LIKE rara i roto i te waahanga WHERE.

Te whakamahi i nga tohu ōrau i roto i nga rara SQL LIKE %te ahua hei tohu i tetahi ahuatanga, he rite ki te whetūriki i roto i te UNIX, i nga whakaaturanga auau ranei *.

Mena karekau he tohu e whakamahia ana %, rara PAI me te tohu rite = He rite tonu te paanga.

wetereo

E whai ake nei te wetereo whānui o te tauākī SQL SELECT ki te panui raraunga mai i te ripanga raraunga ma te whakamahi i te rara PAI:

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

• Ka taea e koe te tohu i tetahi ahuatanga i roto i te rara WHERE.
• Ka taea e koe te whakamahi i te rara PAI i roto i te rara WHERE.
• Ka taea e koe te whakamahi i te rara PAI hei whakakapi i te tohu orite =.
• Ko te rite te nuinga o te wa e hono ana ki % Ka whakamahia tahi, he rite ki te rapunga kupu meta.
• Ka taea e koe te whakamahi ME, OR ranei hei tohu i tetahi, neke atu ranei nga tikanga.
• Ka taea e koe te whakamahi i te WHERE...LIKE rara i roto i nga whakahau MUKU, WHAKAUPAPA ranei hei tohu tikanga.

Ma te whakamahi i te rara PAI i te whakahau whakahau

Kei raro nei ka whakamahia te WHERE...LIKE rara i roto i te whakahau SQL SELECT ki te panui raraunga mai i te ripanga raraunga MySQL chenweiliang_tbl.

Akoranga

E whai ake nei me pehea e whiwhi ai tatou i te mara chenweiliang_author i te ripanga chenweiliang_tbl me COM mo nga rekoata katoa ka mutu ki:

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)

Te whakamahi i te rara PAI ki te tuhinga PHP

Ka taea e koe te whakamahi i te mahi PHP mysqli_query() me te tono SQL SELECT kotahi me te WHERE...LIKE rara hei tiki raraunga.

Ka whakamahia tenei mahi ki te whakahaere i nga whakahau SQL katahi ka whakaputa raraunga mo nga patai katoa ma te mahi PHP mysqli_fetch_assoc().

Engari mena he korero SQL te whakamahi i te WHERE...LIKE rara i roto i te DELETE or UPDATE, kaore he take ki te whakamahi i te mahi mysqli_fetch_array().

Akoranga

Anei me pehea te whakamahi i te tuhinga PHP hei panui i nga rekoata katoa ka mutu ki te COM i te mara chenweiliang_author i te ripanga 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);
?>