php7 数据库操作的 方法

连接数据库的方法PHP7.0以上的:

方法一：

<?php

/* Connect to a MySQL server 连接数据库服务器 */

$link = mysqli_connect(

'localhost', /* The host to connect to 连接MySQL地址 */

'root', /* The user to connect as 连接MySQL用户名 */

'root', /* The password to use 连接MySQL密码 */

'lucax_database'); /* The default database to query 连接数据库名称*/

if (!$link) {

printf("Can't connect to MySQL Server. Errorcode: %s ", mysqli_connect_error());

exit;

}else

echo '数据库连接上了！';

/* Close the connection 关闭连接*/

mysqli_close($link);

?>

https://www.cnblogs.com/jianqingwang/p/5890111.html

方法二：

<?php

$servername = "localhost";

$username = "root";

$password = "root";

$dbname = "myDB";

// 创建连接

# Tip: 如果你使用其他端口（默认为3306），为数据库参数添加空字符串，如: new mysqli("localhost", "username", "password", "", port)

$conn = new mysqli($servername, $username, $password,$dbname);

$conn->close();

?>

http://www.runoob.com/php/php-mysql-connect.html

创建数据库：

方法一:

$sql = "CREATE DATABASE myDB3";

if (mysqli_query($conn, $sql)) {

echo "数据库创建成功";

} else {

echo "Error creating database: " . mysqli_error($conn);

}

方法二:

// 检测连接

if ($conn->connect_error) {

　　die("连接失败: " . $conn->connect_error);

}

echo "连接成功";

$sql = "CREATE DATABASE myDB2";

if ($conn->query($sql) === TRUE) {

　　echo "数据库创建成功";

} else {

　　echo "Error creating database: " . $conn->error;

}

http://www.runoob.com/php/php-mysql-create.html

创建表的方法：

方法一:

// 使用 sql 创建数据表

$sql = "CREATE TABLE MyGuests (

id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,

firstname VARCHAR(30) NOT NULL,

lastname VARCHAR(30) NOT NULL,

email VARCHAR(50),

reg_date TIMESTAMP

)";

if (mysqli_query($conn, $sql)) {

echo "数据表 MyGuests 创建成功";

} else {

echo "创建数据表错误: " . mysqli_error($conn);

}

方法二:

// 使用 sql 创建数据表

$sql = "CREATE TABLE MyGuests2 (

id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,

firstname VARCHAR(30) NOT NULL,

lastname VARCHAR(30) NOT NULL,

email VARCHAR(50),

reg_date TIMESTAMP

)";

if ($conn->query($sql) === TRUE) {

echo "Table MyGuests created successfully";

} else {

echo "创建数据表错误: " . $conn->error;

}

http://www.runoob.com/php/php-mysql-create-table.html

插入数据的方法:

方法一:

$sql = "INSERT INTO MyGuests (firstname, lastname, email)

VALUES ('John', 'Doe', 'john@example.com')";

if (mysqli_query($conn, $sql)) {

echo "新记录插入成功";

} else {

echo "Error: " . $sql . "<br>" . mysqli_error($conn);

}

方法二:

$sql = "INSERT INTO MyGuests (firstname, lastname, email)

VALUES ('John', 'Doe', 'john@example.com')";

if ($conn->query($sql) === TRUE) {

echo "新记录插入成功";

} else {

echo "Error: " . $sql . "<br>" . $conn->error;

}

http://www.runoob.com/php/php-mysql-insert.html

插入多条数据的方法:

方法一:

$sql = "INSERT INTO MyGuests (firstname, lastname, email)

VALUES ('John', 'Doe', 'john@example.com');";

$sql .= "INSERT INTO MyGuests (firstname, lastname, email)

VALUES ('Mary', 'Moe', 'mary@example.com');";

$sql .= "INSERT INTO MyGuests (firstname, lastname, email)

VALUES ('Julie', 'Dooley', 'julie@example.com')";

if (mysqli_multi_query($conn, $sql)) {

echo "新记录插入成功";

} else {

echo "Error: " . $sql . "<br>" . mysqli_error($conn);

}

方法二：

$sql = "INSERT INTO MyGuests (firstname, lastname, email)

VALUES ('22', 'Doe', 'john@example.com');";

$sql .= "INSERT INTO MyGuests (firstname, lastname, email)

VALUES ('22', 'Moe', 'mary@example.com');";

$sql .= "INSERT INTO MyGuests (firstname, lastname, email)

VALUES ('22', 'Dooley', 'julie@example.com')";

if ($conn->multi_query($sql) === TRUE) {

echo "新记录插入成功";

} else {

echo "Error: " . $sql . "<br>" . $conn->error;

}

查询数据库的方法：

方法一:

$sql = "SELECT id, firstname, lastname FROM MyGuests";

$result = mysqli_query($conn, $sql);

if (mysqli_num_rows($result) > 0) {

// 输出数据

while($row = mysqli_fetch_assoc($result)) {

echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";

}

} else {

echo "0 结果";

}

方法二：

$sql = "SELECT id, firstname, lastname FROM MyGuests";

$result = $conn->query($sql);

if ($result->num_rows > 0) {

// 输出数据

while($row = $result->fetch_assoc()) {

echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";

}

} else {

echo "0 结果";

}

http://www.runoob.com/php/php-mysql-select.html

增、删、改、查 都是使用 mysqli_query() 函数

增：http://www.runoob.com/php/php-mysql-insert.html

删：http://www.runoob.com/php/php-mysql-delete.html

改: http://www.runoob.com/php/php-mysql-update.html

查: http://www.runoob.com/php/php-mysql-select.html