Database ea MySQL e botsa data joang tafoleng?Potso/Taelo/Syntax

MySQL databaseMokhoa oa ho botsisisa lintlha tse tafoleng?Polelo ea Potso/Taelo/Sintax

MySQL Lintlha tsa potso

Li-database tsa MySQL li sebelisa lipolelo tsa SQL SELECT ho botsa lintlha.

U ka botsa data ho database ka mysql> fensetere ea taelo ea taelo, kapa ka sengoloa sa PHP.

sebōpeho-puo

Se latelang ke kakaretso ea KHETHA syntax bakeng sa ho botsa data ho database ea MySQL:

SELECT column_name,column_name
FROM table_name
[WHERE Clause]
[OFFSET M ][LIMIT N]

• Polelong ea potso, u ka sebelisa tafole e le 'ngoe kapa ho feta, ua arola litafole ka lifehelo (,), 'me u sebelise polelo ea WHERE ho beha maemo a potso.
• Taelo ea SELECT e ka bala rekoto e le 'ngoe kapa ho feta.
• U ka sebelisa asterisk (*) ho nkela masimo a mang sebaka, polelo ea KHETHA e tla khutlisa data eohle ea tafole.
• U ka sebelisa polelo ea WHERE ho kenyelletsa boemo bofe kapa bofe.
• O ka hlakisa ts'ebetso ea data moo polelo ea KHETHA e qalang potso ka OFFSET.Ka mokhoa o ikhethileng, offset ke 0.
• U ka sebelisa thepa ea LIMIT ho beha palo ea lirekoto tse khutlisitsoeng.

Fumana data ka taelo ea taelo

Mohlaleng o latelang, re tla sebelisa taelo ea SQL SELECT ho fumana lintlha tsa tafole ea data ea MySQL chenweiliang_tbl:

Mohlala

Mohlala o latelang o tla khutlisa lirekoto tsohle tsa tafole ea data chenweiliang_tbl:

select * from chenweiliang_tbl;

Sebelisa mongolo oa PHP ho fumana data

ho sebelisa mesebetsi ea PHP mysqli_query() le SQL KHETHA laela ho fumana data.

Mosebetsi ona o sebelisetsoa ho phethahatsa litaelo tsa SQL ebe o fetisa mesebetsi ea PHP mysqli_fetch_array() ho sebelisa kapa ho hlahisa data bakeng sa lipotso tsohle.

mysqli_fetch_array() Ts'ebetso e nka mola ho tsoa sephethong e le sehlopha sa asociative, kapa palo e ngata ea linomoro, kapa ka bobeli. E khutlisa sehlopha se hlahisoang ho tsoa meleng e nkuoeng ho tsoa sephethong, kapa leshano haeba ho se na mela.

Mohlala o latelang o bala lirekoto tsohle ho tsoa tafoleng ea data chenweiliang_tbl.

Mohlala

Leka mohlala o latelang ho hlahisa lirekoto tsohle tsa tafole ea data 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';
 
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);
?>

Mohlaleng o ka holimo, mola o mong le o mong oa lirekoto tse baloang o abeloa ho feto-fetoha ha $ row, ebe boleng bo bong le bo bong bo hatisoa.

Tlhokomeliso:Hopola hore haeba o hloka ho sebelisa mofuta o fapaneng khoeleng, kenya mofuta ona ka har'a li-braces tse harelaneng.

Mohlala o ka holimo, parameter ea bobeli ea PHP mysqli_fetch_array() mosebetsi ke MYSQL_ASSOC, seta paramethara ena ho botsa sephetho ho khutlisetsa sehlopha sa associative, u ka sebelisa lebitso la tšimo joalo ka index ea sehlopha.

PHP e fana ka ts'ebetso e 'ngoe mysqli_fetch_assoc(), tshebetso e nka mola ho tswa ho sephetho se behiloeng e le sehlopha sa associative.E khutlisa sehlopha sa asociative se hlahisitsoeng meleng e nkiloeng ho sephetho, kapa leshano haeba ho se na mela.

Mohlala

Leka mohlala o latelang, o sebelisang mysqli_fetch_assoc() sebetsa ho hlahisa lirekoto tsohle tsa tafole ea data 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';
 
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_assoc 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($row = mysqli_fetch_assoc($retval))
{
 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);
?>

U ka boela ua sebelisa MYSQL_NUM e sa khaotseng e le parameter ea bobeli ea PHP mysqli_fetch_array() function, e khutlisetsang palo ea linomoro.

Mohlala

Mehlala e latelang e sebelisoa MYSQL_NUM Paramethara e bonts'a lirekoto tsohle tsa tafole ea data 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';
 
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_NUM))
{
 echo "<tr><td> {$row[0]}</td> ".
 "<td>{$row[1]} </td> ".
 "<td>{$row[2]} </td> ".
 "<td>{$row[3]} </td> ".
 "</tr>";
}
echo '</table>';
mysqli_close($conn);
?>

tokollo ya mohopolo

Ke mokhoa o motle oa ho lokolla mohopolo oa cursor ka mor'a hore re phethe polelo ea KHETHA.

Memori e ka lokolloa ka mosebetsi oa PHP mysqli_free_result().

Mohlala o latelang o bontša tšebeliso ea mosebetsi ona.

Mohlala

Leka mehlala e latelang:

Memori ea mahala e nang le mysqli_free_result:

<?
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';
 
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_NUM))
{
 echo "<tr><td> {$row[0]}</td> ".
 "<td>{$row[1]} </td> ".
 "<td>{$row[2]} </td> ".
 "<td>{$row[3]} </td> ".
 "</tr>";
}
echo '</table>';
// 释放内存
mysqli_free_result($retval);
mysqli_close($conn);
?>