Composition and summary of common code segments for PHP operation MySQL

<?php

$con = mysql_connect("【Database Address】","【Database Username】","【Database Password】");//Create MySQL connection
mysql_select_db("【Database Name】", $con);//Select MySQL database
$sql = "CREATE TABLE abc

(

id int NOT NULL AUTO_INCREMENT,

PRIMARY KEY(id),

openid varchar(32),

nickname varchar(32),

sex varchar(8)

)";//Create a data table with the name abc. The id cannot be empty and automatically incremented and set as the primary key
mysql_query($sql,$con);//Execute a MySQL statement
mysql_close($con);//Close mysql connection
?>

<?php

$datatime = date("Y-m-d H:i:s",time());//Get time
$con = mysql_connect("【Database Address】","【Database Username】","【Database Password】");//Create MySQL connection
mysql_select_db("【Database Name】", $con);//Select MySQL database
mysql_query("SET NAMES 'UTF8'");//Set encoding (solve the problem of inserting Chinese garbled code)
mysql_query("INSERT INTO 【Data table name】 (openid, add_time, nickname)

VALUES ('123', '$datatime', 'abc')");//Insert a new record
mysql_close($con);//Close mysql connection
?>

<?php

$con = mysql_connect("【Database Address】","Database username]","【Database Password】");//Create MySQL connection
mysql_select_db("【Database Name】", $con);//Select MySQL database
$result = mysql_query("SELECT * FROM 【Data table name】");//Get all data in the data table
while($row = mysql_fetch_array($result)){//Get a row from the result set as an associative array. If there are no more rows, return false
    echo $row['openid']."
";//The values ​​of all openid fields in the output table
}

mysql_close($con);//Close mysql connection
?>

<?php

$con = mysql_connect("【Database Address】","【Database Username】","【Database Password】");//Create MySQL connection
mysql_select_db("【Database Name】", $con);//Select MySQL database
$result = mysql_query("SELECT * FROM 【Data table name】 WHERE openid='123'");//Get the data row with openid=123 in the data table
while($row = mysql_fetch_array($result)){//Get a row from the result set as an associative array. If there are no more rows, return false
    echo $row['nickname']."
";//The values ​​of all openid fields in the output table
}

mysql_close($con);//Close mysql connection
?>

<?php

$con = mysql_connect("【Database Address】","【Database Username】","【Database Password】");//Create MySQL connection
mysql_select_db("【Database Name】", $con);//Select MySQL database
mysql_query("UPDATE 【Data table name】 SET nickname='new' WHERE openid='123'");//Update nickname field of id=123 record line
mysql_close($con);//Close mysql connection
?>

<?php

$con = mysql_connect("【Database Address】","【Database Username】","【Database Password】");//Create MySQL connection
mysql_select_db("Database Name", $con);//Select MySQL database
mysql_query("DELETE FROM Data table name WHERE openid='123'");//Delete a line of record with openid=123
mysql_close($con);//Close mysql connection
?>

<?php

$con = mysql_connect("【Database Address】","【Database Username】","【Database Password】");//Create MySQL connection
mysql_select_db("Database Name", $con);//Select MySQL database
$sql = "DROP TABLE abc";//Delete the data table named abc
mysql_query($sql,$con);//Execute a MySQL statement
mysql_close($con);//Close mysql connection
?>

<?php

$host = "【Database Address】";

$username = "【Database Username】";

$password = "【Database Password】";

$dbname = "【Database Name】";

//Put the code to be executed into the try block. If an exception occurs in a statement during the execution of these codes, the program will jump directly to the catch block, and $e collects error information and displays.
try {

    $conn = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);//Create a connection
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); //Set PDO error mode, used to throw exceptions
    $sql = "CREATE TABLE abc (

    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,

    openid varchar(32) NOT NULL,

    nickname varchar(32) NOT NULL,

    sex varchar(8) NOT NULL

    )";//Create a data table with the name abc. The id cannot be empty and automatically incremented and set as the primary key
    $conn->exec($sql);//Use exec() without result returns
}

catch(PDOException $e){

    echo $sql . "
" . $e->getMessage();//Show exception information
}

$conn = null;//Close the connection
?>