Uyibuza njani iMySQL njenge?

mysql Ungabuza njani njengo?mysql databaseAmaTshayina athanda ukusetyenziswa kwengxelo

MySQL NJENGOmhlathi

Siyazi ukusebenzisa umyalelo we-SQL KHETHA ukufunda idatha kwi-MySQL, kwaye sinokusebenzisa i-WHERE igatya kwi-SELECT statement ukufumana iirekhodi ezichaziweyo.

Uphawu olulinganayo lunokusetyenziswa kwigatya APHO = Ukuseta iimeko zokufumana idatha, njenge "chenweiliang_author = 'chenweiliang.com'".

Kodwa ngamanye amaxesha kufuneka sifumane zonke iirekhodi ezinendawo ye-chenweiliang_author eneempawu ze-"COM", ngoko ke kufuneka sisebenzise igatya le-SQL LIKE kwigatya elithi WHERE.

Ukusebenzisa iimpawu zepesenti kwi-SQL LIKE amagatya %uphawu lokumela nawuphi na umsebenzi, ngokufanayo neenkwenkwezi kwi UNIX okanye amabinzana aqhelekileyo *,

Ukuba akukho phawu lwepesenti lusetyenziswayo %, NJENGOKU igatya elinophawu olulinganayo = Isiphumo siyafana.

Igrama

Oku kulandelayo yisintaksi ngokubanzi yenkcazo ye-SQL KHETHA ukufunda idatha kwitafile yedatha usebenzisa igatya LIKE:

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

• Ungakhankanya nayiphi na imeko kwigatya apho.
• Ungasebenzisa igatya elithi LIKE kwigatya elithi APHO.
• Ungasebenzisa igatya elithi LIKE endaweni yophawu olulinganayo =,
• LIKE idla ngokunxulunyaniswa ne % Isetyenziswe kunye, ifana nokukhangela i-metacharacter.
• Ungakhankanya imiqathango enye okanye ngaphezulu usebenzisa KUNYE okanye OKANYE.
• Ungasebenzisa APHO...NJENGENZA igatya kwi-CIMA okanye UKUHLAZIYA imiyalelo ukuchaza iimeko.

Ukusebenzisa igatya elithi LIKE kwi-prompt yomyalelo

Ngezantsi siza kusebenzisa APHO...NJENGAMAGAtya kwiSQL KHETHA umyalelo wokufunda idatha kwitafile yedatha yeMySQL chenweiliang_tbl.

Umzekelo

Oku kulandelayo yindlela esizakufumana ngayo i chenweiliang_author field kwi chenweiliang_tbl table nge COM kuzo zonke iirekhodi eziphela ngo:

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)

Usebenzisa igatya LIKE kwiscript sePHP

Ungasebenzisa umsebenzi we-PHP mysqli_query () kunye nomyalelo ofanayo SQL KHETHA nge-APHO...NJENGAMAGAtya okufumana idatha.

Lo msebenzi usetyenziselwa ukuphumeza imiyalelo yeSQL kwaye emva koko imveliso yedata yayo yonke imibuzo ngomsebenzi we PHP mysqli_fetch_assoc().

Kodwa ukuba yingxelo yeSQL usebenzisa APHO...NJENGAMAGAtya kwi CIMA okanye UPDATE, akukho mfuneko yokusebenzisa mysqli_fetch_array() umsebenzi.

Umzekelo

Nantsi indlela esisebenzisa ngayo iskripthi se-PHP ukufunda zonke iirekhodi eziphela ngo-COM kwindawo ye-chenweiliang_author kwitheyibhile 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
 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);
?>