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MySQL以'YYYY-MM-DD HH:MM:SS'格式检索并显示DATETIME值。日期只能存储此类型,但它可以与许多时间格式函数一起使用来更改并显示它。

当使用PHP在MySQL中编写查询时,它的适用性将基于MySQL本身进行检查。所以使用MySQL提供的默认日期和时间格式,即'YYYY-MM-DD'

ATE: YYYY-MM-DD

Example: 2019-01-28

DATETIME: YYYY-MM-DD HH:MI:SS

Example: 2019-01-28 23:50:30

TIMESTAMP: YYYY-MM-DD HH:MI:SS

Example: 2019-01-28 23:50:30

YEAR: YYYY or YY

CREATE DATABASE Date_time_example;

示例1:用于创建数据库和表的PHP程序

$servername = "localhost";

$username = "root";

$password = "";

$dbname = "test";

// 创建连接

$conn = mysqli_connect( $servername, $username, $password, $dbname );

// 检查连接

if ( !$conn ) {

die("Connection failed: " . mysqli_connect_error());

// 创建表的SQL查询

$sql = "CREATE TABLE date_test (

id INT AUTO_INCREMENT PRIMARY KEY,

created_at DATETIME

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

echo "Table date_test created successfully";

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

// 关闭连接

mysqli_close($conn);

Table date_test created successfully

示例2:将日期插入表中的PHP程序。

$servername = "localhost";

$username = "root";

$password = "";

$dbname = "test";

// 创建连接

$conn = mysqli_connect( $servername, $username, $password, $dbname );

// 检查连接

if ( !$conn ) {

die("Connection failed: " . mysqli_connect_error());

// 用于向表中插入数据的SQL查询

$sql = "INSERT INTO date_test( created_at )

VALUES( '2019-01-28 12:39:16' );";

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

echo "New record created successfully";

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

// 关闭连接

mysqli_close($conn);

New record created successfully

示例3:此示例用于显示在2019-01-28上创建的行。使用以下查询显示结果。created_at列不仅包含日期,还包含时间。所以它会显示错误信息。

SELECT * FROM date_test WHERE DATE( created_at ) = '2019-01-28';

$servername = "localhost";

$username = "root";

$password = "";

$dbname = "test";

//创建连接

$conn = mysqli_connect( $servername, $username, $password, $dbname );

// 检查连接

if ( !$conn ) {

die("Connection failed: " . mysqli_connect_error());

//SQL查询

$sql = "SELECT * FROM date_test

WHERE DATE(created_at) = '2019-01-28'";

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

if ($result) {

echo $result; //打印查询结果

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

// 关闭连接

mysqli_close($conn);

id  created_at

1   2019-01-28 12:39:16

要从DATETIME值获取年,季度,月,周,日,小时,分钟和秒,请使用以下语句中显示的函数:

HOUR(@dt),MINUTE(@dt),SECOND(@dt) ),DAY(@dt),WEEK(@dt),MONTH(@dt),QUARTER(@dt),YEAR(@dt);

推荐参考学习:

《PHP教程》

《mysql教程》

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