PHP_MYSQL基础操作

最新推荐文章于 2025-02-17 20:26:23 发布

furway

最新推荐文章于 2025-02-17 20:26:23 发布

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分类专栏： php mysql 文章标签： php mysql 数据库

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PHP MySQL Insert Into

SQL 语句对大小写不敏感。INSERT INTO跟insert into相同。
INSERT INTO 语句用于向数据库表中插入新记录。

语法:
INSERT INTO table_name VALUES (value1, value2,.....)

可以规定在其中插入数据的列：

INSERT INTO table_name(column1,column2,...)VALUES(value1,value2,...)

<?php

$con = mysql_connect("localhost","HongLing","123456");
if(!$con){
die('Could not connect: ' . mysql_error());
}

mysql_select_db("my_db", $con);

mysql_query("INSERT INTO HongLing(FirstName, LastName, Age)
VALUES('Chen', 'XiaoWei', '35')");

mysql_query("INSERT INTO HongLing(FirstName, LastName, Age)
VALUES('Tian','HongLing','33')");

mysql_close($con);
?>

把来自表单的数据插入数据库

<html>
<body>
<form action="insert.php" method="post">
FirstName:<input type="text" name="firstname" />
LastName:<input type="text" name="lastname" />
Age:<input type="text" name="age" />
<inpput type="submit" />
</form>
</body>
</html>

当用户点击HTML表单中的提交按钮时，表单数据被发送到"insert.php"。
"insert.php"文件连接数据库，并通过$_POST变量从表单取回值。
然后，mysql_query()函数执行INSERT INTO 语句。

<?php
$con = mysql_connect("localhost", "HongLing", "abc123");
if(!$con){
die('Could not connect: ' . mysql_error());
}

mysql_select_db("my_db", $con);

$sql="INSERT INTO Persons(Firstname,LastName,Age)
VALUES('$_POST[firstname]','$_POST[lastname]','$_POST[age]')";

if(!mysql_query($sql,$con)){
die('Error: ' . mysql_error());
}
echo "1 record added";

mysql_close($con)
?>

SELECT语句用于从数据库中选取数据

语法：
SELECT column_name(s) FROM table_name

<?php

$con = mysql_connect("localhost","HongLing","123456");
if(!$con){
die('Could not connect: ' . mysql_error());

}

mysql_select_db("my_db", $con);
$result = mysql_query("SELECT * FROM Persons");

while($row = mysql_fetch_array($result)){
echo $row['FirstName' . " " . $row['LastName']];
echo "<br />";
}

mysql_close($con);
?>

在HTML表格中显示结果

<?php
$con = mysql_connect("localhost", "HongLing","123456");
if(!$con){
die('Could not connect: ' . mysql_error());
}

mysql_select_db("my_db", $con);
$result = mysql_query("SELECT * FROM Persons");
echo "<table border='1'>
<tr>
<th>FirstName</th>
<th>LastName</th>
</tr>";

while($row = mysql_fetch_array($result)){
echo "<tr>";
echo "<td>" . $row['FirstName'] . "</td>";
echo "<td>" . $row['LastName'] . "</td>"
echo "</tr>";
}
echo "</table>";

mysql_close($con);

?>

在HTML表格中显示结果

<?php
$con = mysql_connect("localhost" ,"HongLing","123456");
if(!$con){
die('Could not connect: ' . mysql_error());
}

mysql_select_db("my_db",$con);
$result = mysql_query("select * from Persons");

echo "<table border='1'>
<tr>
<th>FirstName</th>
<th>LastName</th>
</tr>";

while($row = mysql_fetch_array($result)){
echo "<tr>";
echo "<td>" . $row['FirstName'] . "</td>";
echo "<td>" . $row['LastName'] . "</td>";
}
echo "</table>"

mysql_close($con);
?>

PHP MySQL Where 子句

SELECT column FROM table WHERE column operator value

PHP MySQL Order By 关键词

语法:

SELECT Column_name(s)
FROM table_name
ORDER BY column_name

<?php

$con = mysql_connect("localhost","HongLing","123456");
if(!$con){
die('Could not connect: ' . mysql_error());
}

mysql_select_db("my_db", $con);

$result = mysql_query("SELECT * FROM Persons ORDER BY age");

while($row = mysql_fetch_array($result)){
echo $row['FirstName'];
echo " " . $row['LastName'];
echo " " . $row['Age'];
echo "<br />";
}

mysql_close($con);

?>

升序或降序

如果您使用ORDER BY 关键词，记录集的排序顺序默认是升序,请使用DESC关键词来设定降序排序:

SELECT column_name(s)
FROM table_name
ORDER BY column_name DESC

根据两列进行排序

SELECT Column_name(s)
FROM table_name
ORDER BY column_name1,column2

PHP MySQL Update

UPDATE语句用于在数据库表中修改数据

语法:

UPDATE table_name
SET column_name = new_value
WHERE column_name = some_value

<?php

$con = mysql_connect("localhost","HongLing","123456");
if(!$con){

die('Could not connect: ' . mysql_error());
}
mysql_select_db("my_db",$con);

mysql_query("UPDATE Persons SET Age= '36'
WHERE FirstName = 'Peter' AND LastName = 'Griffin'");

mysql_close($con);
?>

PHP MySQL Delete From

DELETE FROM 语句用于从数据库中删除记录。

DELETE FROM table_name
WHERE column_name = some_value

<?php

$con = mysql_connect("localhost", "HongLing", "123456");
if(!$con){
die('Could not connect: ' . mysql_error());
}

mysql_select_db("my_db",$con);

mysql_query("DELETE FROM Persons WHERE LastName='Griffin'");
mysql_close($con);
?>