PHP MySQL Create and Drop Tables

Use the query function to get PHP to execute the SQL statements: query is used to send a query or command to a MySQL connection. A database must be selected before a table can be dropped or created. The database is selected with the mysqli function with one more parameter. The following example drops and creates a table using the following SQL commands: 

DROP TABLE CDs;

CREATE TABLE CDs (
  ASIN  CHAR(10) PRIMARY KEY,
  Title VARCHAR(32) NOT NULL,
  price REAL CHECK( price > 0.0 ) );

            
 <html><body>
 <?php
  $servername = "undcsmysql.mysql.database.azure.com";
  $username   = "user.id@undcsmysql";
  $password   = "password";
  $dbname     = "user_id";         # your database or schema
  // Connect to the database.
  $conn       = new mysqli( $servername, $username, $password, $dbname );

  $action =  Drop    Create 

  if ( $action == "Drop" ) {      
    // Drop table CDs.
    $conn->query( "DROP TABLE CDs" );
    echo "Table CDs dropped";
  }

  elseif ( $action == "Create" ) {
    // Create table CDs.
    $sql = "CREATE TABLE CDs (
  ASIN  CHAR(10) PRIMARY KEY,
  Title VARCHAR(32) NOT NULL,
  price REAL CHECK( price > 0.0 ) )";
    $conn->query( $sql );
    echo "Table CDs created";
  }
  $conn->close( );
 ?>
 </body></html>

When you create a database field of type VARCHAR, you must specify the maximum length of the field, e.g. VARCHAR(15). The CREATE TABLE statement is complicated. For further studies,