Tuhinga Tuhinga
MySQLKōmaka herenga āpure maha?MySQL raupapa ma te heke me te pikinga korero patai/mahi
momo MySQL
E mohio ana matou ki te whakamahi i te korero SQL SELECT ki te panui raraunga mai i te ripanga MySQL.
Mena ka hiahia taatau ki te whakariterite i nga raraunga panui, ka taea e taatau te whakamahi i a MySQL Tuhinga o mua rara hei tautuhi ko tehea mara e hiahia ana koe ki te whakariterite ma tehea huarahi, ka whakahoki i nga hua rapu.
wetereo
E whai ake nei he tauākī SQL SELECT e whakamahi ana i te ORDER BY clause ki te kōmaka i te raraunga uiui i mua i te whakahoki i te raraunga:
SELECT field1, field2,...fieldN table_name1, table_name2... ORDER BY field1, [field2...] [ASC [DESC]]
- Ka taea e koe te whakamahi i tetahi mara hei ahua ahua hei whakahoki i nga hua uiui kua tohua.
- Ka taea e koe te whakarite i nga mara maha hei komaka.
- Ka taea e koe te whakamahi i nga kupumatua ASC, DESC ranei ki te whakarite i nga hua uiui kia tohua kia piki ake, heke iho ranei.Ma te taunoa, kei te raupapa aupiki.
- Ka taea e koe te taapiri WHERE...LIKE rara hei whakatakoto tikanga.
Ma te whakamahi i te ORDER BY rara i te whakahau whakahau
Ko nga mea e whai ake nei ka whakamahi i te ORDER BY clause i roto i te korero SQL SELECT ki te panui i nga raraunga i roto i te ripanga raraunga MySQL chenweiliang_tbl:
Akoranga
Whakamātauria ngā tauira i raro nei, ka kōmakaia ngā hua i roto i te raupapa piki me te heke.
momo SQL
mysql> use chenweiliang; Database changed mysql> SELECT * from chenweiliang_tbl ORDER BY submission_date ASC; +-----------+---------------+---------------+-----------------+ | 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 | | 1 | 学习 PHP | 陈沩亮博客 | 2017-04-12 | | 2 | 学习 MySQL | 陈沩亮博客 | 2017-04-12 | +-----------+---------------+---------------+-----------------+ 4 rows in set (0.01 sec) mysql> SELECT * from chenweiliang_tbl ORDER BY submission_date DESC; +-----------+---------------+---------------+-----------------+ | chenweiliang_id | chenweiliang_title | chenweiliang_author | submission_date | +-----------+---------------+---------------+-----------------+ | 1 | 学习 PHP | 陈沩亮博客 | 2017-04-12 | | 2 | 学习 MySQL | 陈沩亮博客 | 2017-04-12 | | 4 | 学习 Python | chenweiliang.com | 2016-03-06 | | 3 | 学习 Java | chenweiliang.com | 2015-05-01 | +-----------+---------------+---------------+-----------------+ 4 rows in set (0.01 sec)
Panuitia nga raraunga katoa i roto i te ripanga chenweiliang_tbl me te whakariterite i runga i te raupapa aupiki ma te mara tuku_ra.
Te whakamahi i te ORDER BY rara i roto i te tuhinga PHP
Ka taea e koe te whakamahi i te mahi PHP mysqli_query() me te tono SQL SELECT kotahi me te ORDER BY rara hei tiki raraunga.
Ka whakamahia tenei mahi ki te whakahaere i nga whakahau SQL ka whakaputa i nga raraunga patai katoa ma te mahi PHP mysqli_fetch_array().
Akoranga
Whakamātauria te tauira e whai ake nei, ka whakahokia te raraunga i uiuia i raro i te raupapa o te mara tuku_ra.
MySQL ORDER MA te whakamatautau:
<?
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
ORDER BY submission_date ASC';
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 MySQL ORDER BY 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);
?>Hope Chen Weiliang Blog ( https://www.chenweiliang.com/ ) i tohatohahia "MySQL multi-field conditional sorting? MySQL order by descending and ascending query statement/function", he pai ki a koe.
Nau mai ki te tohatoha i te hono o tenei tuhinga:https://www.chenweiliang.com/cwl-476.html