PHP如何操作數據庫

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                                                           連接數據庫

error_reporting(0);
$dbhost = 'localhost';  // mysql服務器主機地址
$dbuser = 'root';            // mysql用戶名
$dbpass = '123456';          // mysql用戶名密碼
$conn = mysqli_connect($dbhost, $dbuser, $dbpass);
if(! $conn )
{
    die('數據庫連接失敗');
}
echo '數據庫連接成功';

創建數據庫（推薦學習：《mysql視頻教程》）

$sql = 'CREATE DATABASE RUNOOB';
$retval = mysqli_query($conn,$sql );
if(! $retval )
{
    die('數據庫創建失敗');
}
echo "數據庫創建成功";

刪除數據庫

$sql = 'DROP DATABASE RUNOOB';
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die('數據庫刪除失敗');
}
echo "數據庫刪除成功";

選擇數據庫

mysqli_select_db($conn, 'RUNOOB' );

數據類型

數值、日期/時間、字符串

數值類型
tinyint
smallint
medium
int/integer
bigint
float
double
decimal
日期/時間
date
time
datetime
timestamp
字符串
char
varchar
tinyblob
tinytext
blob
text
mediumblob
mediumtext
longblob
longtext

創建數據表

$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, 'RUNOOB' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die('創建數據表失敗');
}
echo "創建數據表成功";

刪除數據表

$sql = "DROP TABLE runoob_tbl";
mysqli_select_db( $conn, 'RUNOOB' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
  die('刪除數據表失敗');
}
echo "刪除數據表成功";

插入數據

// 設置編碼，防止中文亂碼
mysqli_query($conn , "set names utf8");
 
$runoob_title = '學習 Python';
$runoob_author = 'RUNOOB.COM';
$submission_date = '2016-03-06';
 
$sql = "INSERT INTO runoob_tbl ".
        "(runoob_title,runoob_author, submission_date) ".
        "VALUES ".
        "('$runoob_title','$runoob_author','$submission_date')";
 
 
 
mysqli_select_db( $conn, 'RUNOOB' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
  die('插入數據失敗');
}
echo "數據插入成功";

查詢數據

// 設置編碼，防止中文亂碼
mysqli_query($conn , "set names utf8");
 
$sql = 'SELECT runoob_id, runoob_title, 
        runoob_author, submission_date
        FROM runoob_tbl';
 
mysqli_select_db( $conn, 'RUNOOB' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die('無法讀取數據');
}
echo '<h3>菜鳥教程 mysqli_fetch_array 測試<h3>';
echo '<table border="1"><tr><td>教程 ID</td><td>標題</td><td>作者</td><td>提交日期</td></tr>';
while($row = mysqli_fetch_array($retval, MYSQLI_ASSOC))
{
    echo "<tr><td> {$row['runoob_id']}</td> ".
         "<td>{$row['runoob_title']} </td> ".
         "<td>{$row['runoob_author']} </td> ".
         "<td>{$row['submission_date']} </td> ".
         "</tr>";
}
echo '</table>';

WHERE

// 設置編碼，防止中文亂碼
mysqli_query($conn , "set names utf8");
 
// 讀取 runoob_author 為 RUNOOB.COM 的數據
$sql = 'SELECT runoob_id, runoob_title, 
        runoob_author, submission_date
        FROM runoob_tbl
        WHERE runoob_author="RUNOOB.COM"';
 
mysqli_select_db( $conn, 'RUNOOB' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die('無法讀取數據: ' . mysqli_error($conn));
}
echo '<h3>菜鳥教程 MySQL WHERE 子句測試<h3>';
echo '<table border="1"><tr><td>教程 ID</td><td>標題</td><td>作者</td><td>提交日期</td></tr>';
while($row = mysqli_fetch_array($retval, MYSQL_ASSOC))
{
    echo "<tr><td> {$row['runoob_id']}</td> ".
         "<td>{$row['runoob_title']} </td> ".
         "<td>{$row['runoob_author']} </td> ".
         "<td>{$row['submission_date']} </td> ".
         "</tr>";
}
echo '</table>';
// 釋放內存
mysqli_free_result($retval);

UPDATE

// 設置編碼，防止中文亂碼
mysqli_query($conn , "set names utf8");
 
$sql = 'UPDATE runoob_tbl
        SET runoob_title="學習 Python"
        WHERE runoob_id=3';
 
mysqli_select_db( $conn, 'RUNOOB' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die('無法更新數據: ' . mysqli_error($conn));
}
echo '數據更新成功！';

DELETE

// 設置編碼，防止中文亂碼
mysqli_query($conn , "set names utf8");
 
$sql = 'DELETE FROM runoob_tbl
        WHERE runoob_id=3';
 
mysqli_select_db( $conn, 'RUNOOB' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die('無法刪除數據: ' . mysqli_error($conn));
}
echo '數據刪除成功！';

LINK

// 設置編碼，防止中文亂碼
mysqli_query($conn , "set names utf8");
 
$sql = 'SELECT runoob_id, runoob_title, 
        runoob_author, submission_date
        FROM runoob_tbl
        WHERE runoob_author LIKE "%COM"';
 
mysqli_select_db( $conn, 'RUNOOB' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
    die('無法讀取數據: ' . mysqli_error($conn));
}
echo '<h3>菜鳥教程 mysqli_fetch_array 測試<h3>';
echo '<table border="1"><tr><td>教程 ID</td><td>標題</td><td>作者</td><td>提交日期</td></tr>';
while($row = mysqli_fetch_array($retval, MYSQLI_ASSOC))
{
    echo "<tr><td> {$row['runoob_id']}</td> ".
         "<td>{$row['runoob_title']} </td> ".
         "<td>{$row['runoob_author']} </td> ".
         "<td>{$row['submission_date']} </td> ".
         "</tr>";
}
echo '</table>';

排序

$sql = 'SELECT runoob_id, runoob_title, 
        runoob_author, submission_date
        FROM runoob_tbl
        ORDER BY  submission_date ASC(DESC)';
升序(降序)
默認升序

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