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PHP操作数据库

angryTom

发布： 2019-10-12 15:34:08

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连接数据库

error_reporting(0);
$dbhost = &#39;localhost&#39;;  // <a style='color:#f60; text-decoration:underline;' href="https://www.php.cn/zt/15713.html" target="_blank">mysql</a>服务器主机地址
$dbuser = &#39;root&#39;;            // mysql用户名
$dbpass = &#39;123456&#39;;          // mysql用户名密码
$conn = mysqli_connect($dbhost, $dbuser, $dbpass);
if(! $conn )
{
    die(&#39;数据库连接失败&#39;);
}
echo &#39;数据库连接成功&#39;;

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创建数据库（推荐学习：《mysql视频教程》）

$sql = &#39;CREATE DATABASE RUNOOB&#39;;
$retval = mysqli_query($conn,$sql );
if(! $retval )
{
    die(&#39;数据库创建失败&#39;);
}
echo "数据库创建成功";

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删除数据库

$sql = &#39;DROP DATABASE RUNOOB&#39;;
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die(&#39;数据库删除失败&#39;);
}
echo "数据库删除成功";

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选择数据库

mysqli_select_db($conn, &#39;RUNOOB&#39; );

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数据类型

数值、日期/时间、字符串

数值类型
tinyint
smallint
medium
int/integer
bigint
float
double
decimal
日期/时间
date
time
datetime
timestamp
字符串
char
varchar
tinyblob
tinytext
blob
text
mediumblob
mediumtext
longblob
longtext

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创建数据表

$sql = "CREATE TABLE runoob_tbl( ".
        "runoob_id INT NOT NULL AUTO_INCREMENT, ".
        "runoob_title VARCHAR(100) NOT NULL, ".
        "runoob_author VARCHAR(40) NOT NULL, ".
        "submission_date DATE, ".
        "PRIMARY KEY ( runoob_id ))ENGINE=InnoDB DEFAULT CHARSET=utf8; ";
mysqli_select_db( $conn, &#39;RUNOOB&#39; );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die(&#39;创建数据表失败&#39;);
}
echo "创建数据表成功";

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删除数据表

$sql = "DROP TABLE runoob_tbl";
mysqli_select_db( $conn, &#39;RUNOOB&#39; );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
  die(&#39;删除数据表失败&#39;);
}
echo "删除数据表成功";

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插入数据

// 设置编码，防止中文乱码
mysqli_query($conn , "set names utf8");
 
$runoob_title = &#39;学习 Python&#39;;
$runoob_author = &#39;RUNOOB.COM&#39;;
$submission_date = &#39;2016-03-06&#39;;
 
$sql = "INSERT INTO runoob_tbl ".
        "(runoob_title,runoob_author, submission_date) ".
        "VALUES ".
        "(&#39;$runoob_title&#39;,&#39;$runoob_author&#39;,&#39;$submission_date&#39;)";
 
 
 
mysqli_select_db( $conn, &#39;RUNOOB&#39; );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
  die(&#39;插入数据失败&#39;);
}
echo "数据插入成功";

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查询数据

// 设置编码，防止中文乱码
mysqli_query($conn , "set names utf8");
 
$sql = &#39;SELECT runoob_id, runoob_title, 
        runoob_author, submission_date
        FROM runoob_tbl&#39;;
 
mysqli_select_db( $conn, &#39;RUNOOB&#39; );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die(&#39;无法读取数据&#39;);
}
echo &#39;<h2>菜鸟教程 mysqli_fetch_array 测试<h2>&#39;;
echo &#39;<table border="1"><tr><td>教程 ID</td><td>标题</td><td>作者</td><td>提交日期</td></tr>&#39;;
while($row = mysqli_fetch_array($retval, MYSQLI_ASSOC))
{
    echo "<tr><td> {$row[&#39;runoob_id&#39;]}</td> ".
         "<td>{$row[&#39;runoob_title&#39;]} </td> ".
         "<td>{$row[&#39;runoob_author&#39;]} </td> ".
         "<td>{$row[&#39;submission_date&#39;]} </td> ".
         "</tr>";
}
echo &#39;</table>&#39;;

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WHERE

// 设置编码，防止中文乱码
mysqli_query($conn , "set names utf8");
 
// 读取 runoob_author 为 RUNOOB.COM 的数据
$sql = &#39;SELECT runoob_id, runoob_title, 
        runoob_author, submission_date
        FROM runoob_tbl
        WHERE runoob_author="RUNOOB.COM"&#39;;
 
mysqli_select_db( $conn, &#39;RUNOOB&#39; );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die(&#39;无法读取数据: &#39; . mysqli_error($conn));
}
echo &#39;<h2>菜鸟教程 MySQL WHERE 子句测试<h2>&#39;;
echo &#39;<table border="1"><tr><td>教程 ID</td><td>标题</td><td>作者</td><td>提交日期</td></tr>&#39;;
while($row = mysqli_fetch_array($retval, MYSQL_ASSOC))
{
    echo "<tr><td> {$row[&#39;runoob_id&#39;]}</td> ".
         "<td>{$row[&#39;runoob_title&#39;]} </td> ".
         "<td>{$row[&#39;runoob_author&#39;]} </td> ".
         "<td>{$row[&#39;submission_date&#39;]} </td> ".
         "</tr>";
}
echo &#39;</table>&#39;;
// 释放内存
mysqli_free_result($retval);

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UPDATE

// 设置编码，防止中文乱码
mysqli_query($conn , "set names utf8");
 
$sql = &#39;UPDATE runoob_tbl
        SET runoob_title="学习 Python"
        WHERE runoob_id=3&#39;;
 
mysqli_select_db( $conn, &#39;RUNOOB&#39; );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die(&#39;无法更新数据: &#39; . mysqli_error($conn));
}
echo &#39;数据更新成功！&#39;;

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DELETE

// 设置编码，防止中文乱码
mysqli_query($conn , "set names utf8");
 
$sql = &#39;DELETE FROM runoob_tbl
        WHERE runoob_id=3&#39;;
 
mysqli_select_db( $conn, &#39;RUNOOB&#39; );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die(&#39;无法删除数据: &#39; . mysqli_error($conn));
}
echo &#39;数据删除成功！&#39;;

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LINK

// 设置编码，防止中文乱码
mysqli_query($conn , "set names utf8");
 
$sql = &#39;SELECT runoob_id, runoob_title, 
        runoob_author, submission_date
        FROM runoob_tbl
        WHERE runoob_author LIKE "%COM"&#39;;
 
mysqli_select_db( $conn, &#39;RUNOOB&#39; );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die(&#39;无法读取数据: &#39; . mysqli_error($conn));
}
echo &#39;<h2>菜鸟教程 mysqli_fetch_array 测试<h2>&#39;;
echo &#39;<table border="1"><tr><td>教程 ID</td><td>标题</td><td>作者</td><td>提交日期</td></tr>&#39;;
while($row = mysqli_fetch_array($retval, MYSQLI_ASSOC))
{
    echo "<tr><td> {$row[&#39;runoob_id&#39;]}</td> ".
         "<td>{$row[&#39;runoob_title&#39;]} </td> ".
         "<td>{$row[&#39;runoob_author&#39;]} </td> ".
         "<td>{$row[&#39;submission_date&#39;]} </td> ".
         "</tr>";
}
echo &#39;</table>&#39;;

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排序

$sql = &#39;SELECT runoob_id, runoob_title, 
        runoob_author, submission_date
        FROM runoob_tbl
        ORDER BY  submission_date ASC(DESC)&#39;;
升序(降序)
默认升序

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