PHP MySQL - Error: No Database selected

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傲寒
傲寒 2020-12-22 14:23

I am trying to read and write to a database. Here is the code I have so far:

$mysql = mysqli_connect(\"example.com\", \"johndoe\", \"abc123\"); // replace wi         


        
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  • 2020-12-22 14:29

    Please check syntax of mysqli, it takes 4 parameters.You also have to provide database name.

    $link = mysqli_connect("myhost","myuser","mypassw","my_db");
    
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  • 2020-12-22 14:30

    First check mysqli_select_db if it returns false then create database.

    try like this:

     $mysql = mysqli_connect("example.com", "johndoe", "abc123") or die(mysqli_connect_error()); // replace with actual credidentials
    
    if (!mysqli_select_db($mysql,'hardestgame_accounts')) {
     $sql = "CREATE DATABASE IF NOT EXISTS hardestgame_accounts";
     if (!mysqli_query($mysql, $sql)) {
        echo "Error creating database: " . mysqli_error($mysql);
     }
    }
    if (mysqli_connect_errno()) {
        echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
    $sql = "CREATE TABLE IF NOT EXISTS Users(ID INT NOT NULL AUTO_INCREMENT, PRIMARY KEY(ID), username CHAR(15), password CHAR(15), email CHAR(50))";
    if (!mysqli_query($mysql, $sql)) {
        echo "Error creating table: " . mysqli_error($mysql);
    }
    mysqli_close($mysql);
    

    here is a good answer: Php mysql create database if not exists

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  • 2020-12-22 14:31

    Use ` backticks for MYSQL reserved words... your table name is reserved word for MYSQL... Change your table name.

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  • 2020-12-22 14:42

    Obviously the answer is in your error. You didn't select any database. When using this function mysqli_connect specify the database you want to connect to.

    Here is the syntax of the function: http://www.w3schools.com/Php/func_mysqli_connect.asp .

    1) Create your database outside of your application

    2) Specify mysqli_connect with the database you want to select.

    You can also use another function called mysqli_select_db . You can find the sytanx here : http://www.w3schools.com/php/func_mysqli_select_db.asp .

    As already stated in the comment, you will also have to replace : "example.com" with your ip address, if you are running locally replace it with 127.0.0.1:3306 , if you didn't change the port when you installed your mysql database / "johndoe" with your database account, you can change that to "root" / "abc123" with your root account password DEFAULT : "" .

    Good luck !

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  • 2020-12-22 14:49

    You're missing database in mysqli_connect() call

    $link = mysqli_connect("hostname","username","password","database") or die("Error " . mysqli_error($link));
    
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  • 2020-12-22 14:49

    Try using mysql_select_db in between the database connection and the table creation.

    Also, mysql_ is deprecated, please use mysqli_ instead

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