php mysqli简单的增删查改
时间: 2023-09-15 19:20:08 浏览: 47
1. 增加数据:
```php
//连接数据库
$conn = new mysqli("localhost", "username", "password", "database");
//插入数据
$sql = "INSERT INTO `table` (`column1`, `column2`) VALUES ('value1', 'value2')";
if ($conn->query($sql) === TRUE) {
echo "插入成功";
} else {
echo "插入失败: " . $conn->error;
}
//关闭数据库连接
$conn->close();
```
2. 删除数据:
```php
//连接数据库
$conn = new mysqli("localhost", "username", "password", "database");
//删除数据
$sql = "DELETE FROM `table` WHERE `column1`='value1'";
if ($conn->query($sql) === TRUE) {
echo "删除成功";
} else {
echo "删除失败: " . $conn->error;
}
//关闭数据库连接
$conn->close();
```
3. 查询数据:
```php
//连接数据库
$conn = new mysqli("localhost", "username", "password", "database");
//查询数据
$sql = "SELECT * FROM `table`";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
//输出数据
while($row = $result->fetch_assoc()) {
echo "column1: " . $row["column1"]. " - column2: " . $row["column2"]. "<br>";
}
} else {
echo "没有数据";
}
//关闭数据库连接
$conn->close();
```
4. 修改数据:
```php
//连接数据库
$conn = new mysqli("localhost", "username", "password", "database");
//修改数据
$sql = "UPDATE `table` SET `column1`='newvalue1' WHERE `column2`='value2'";
if ($conn->query($sql) === TRUE) {
echo "修改成功";
} else {
echo "修改失败: " . $conn->error;
}
//关闭数据库连接
$conn->close();
```