Ko MySQL database inobvunza sei data mutafura?Chirevo chemubvunzo/Murairo/Syntax

Maitiro ekutsvaga data kubva patafura iri mudhatabhesi reMySQL ? Query statement/command/syntax

MySQL Query data

MySQL dhatabhesi inoshandisa SQL SELECT zvirevo kubvunza data.

Unogona kubvunza data mudhatabhesi kuburikidza ne mysql> yekuraira hwindo, kana kuburikidza neiyo PHP script.

girama

Inotevera ndiyo yakajairika SELECT syntax yekubvunza data muMySQL dhatabhesi:

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

• Muchirevo chemubvunzo, unogona kushandisa tafura imwe kana anopfuura, patsanura matafura nemakoma (,), uye shandisa chirevo cheWHERE kuseta mamiriro emubvunzo.
• Iwo SELECT command inogona kuverenga imwe kana akawanda marekodhi.
• Unogona kushandisa asterisk (*) kutsiva mamwe minda, iyo SELECT statement inodzosa ese emunda data retafura.
• Unogona kushandisa WHERE chirevo kuisa chero mamiriro.
• Iwe unogona kutsanangura iyo data offset apo iyo SELECT statement inotanga mubvunzo ne OFFSET.Nekusarudzika iyo offset ndeye 0.
• Unogona kushandisa LIMIT pfuma kuseta nhamba yemarekodhi akadzorerwa.

Wana data kuburikidza nekuraira kukurumidza

Mumuenzaniso unotevera, isu tichashandisa iyo SQL SELECT command kuti tiwane data reMySQL data tafura chenweiliang_tbl:

muenzaniso

Muenzaniso unotevera uchadzosa marekodhi ese etafura yedata chenweiliang_tbl:

select * from chenweiliang_tbl;

Shandisa PHP script kuti uwane data

Shandisa basa rePHP rekuti mysqli_query() uye murairo weSQL SELECT kuti uwanezve data.

Basa iri rinoshandiswa kuita mirairo yeSQL, uye basa rePHP rekuti mysqli_fetch_array() rinoshandiswa kuwana kana kuburitsa data rese rakabvunzwa.

Basa re mysqli_fetch_array() rinotora mutsara kubva mumhedzisiro se associative array, nhamba yenhamba, kana zvese, uye rinodzosera mutsara wakagadzirwa kubva mumutsara wakawanikwa kubva mumhedzisiro. Kana pasina mimwe mitsara, inodzoka yenhema.

Muenzaniso unotevera unoverenga zvinyorwa zvese kubva patafura yedata chenweiliang_tbl.

muenzaniso

Edza unotevera muenzaniso kuratidza marekodhi ese etafura yedata 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);
?>

Mumuenzaniso uri pamusoro apa, mutsara wega wega wezvinyorwa zvinoverengwa unogoverwa kune yakasiyana $ row, uye ipapo kukosha kwega kwega kunodhindwa kunze.

Cherechedza: Yeuka kuisa chinoshanduka muzvisungo zvakamonana kana uchida kuchishandisa mumutsara.

Mumuenzaniso uri pamusoro apa, parameter yechipiri yebasa rePHP mysqli_fetch_array() ndiMYSQL_ASSOC . Kuisa parameter iyi kunodzosa associative array, uye unogona kushandisa zita remunda se indekisi ye array.

PHP inopa rimwe basa, `mysqli_fetch_assoc()` , iro rinotora mutsara mumwe kubva mumhedzisiro se associative array. Rinodzosera associative array zvichibva pamitsara yakatorwa kubva mumhedzisiro; kana pasina mimwe mitsara iripo, rinodzoka renhema.

muenzaniso

Edza muenzaniso unotevera, unoshandisa basa re mysqli_fetch_assoc() kuburitsa zvinyorwa zvese zvetafura ye 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);
?>

Iwe unogona zvakare kushandisa iyo inogara iripo MYSQL_NUM seyechipiri parameter yePHP mysqli_fetch_array() basa, iyo inodzosa nhevedzano yenhamba.

muenzaniso

Muenzaniso unotevera unoshandisa MYSQL_NUM parameter kuratidza zvinyorwa zvese zviri mutafura 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);
?>

ndangariro kusunungurwa

Itsika yakanaka kusunungura ndangariro dzekasa mushure mekunge taita SARUDZO chirevo.

Iyo ndangariro inogona kuburitswa kuburikidza neiyo PHP basa mysqli_free_result ().

Muenzaniso unotevera unoratidza kushandiswa kwebasa iri.

muenzaniso

Edza mienzaniso inotevera:

Yemahara ndangariro ine 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);
?>