The Code Sample of Database Table Deletion

The following program is used to implement the button “Clear system” of the previous interface.

http://undcemcs01.und.edu/~wen.chen.hu/course/515/2/Clear.php
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01<?php
02 
03 # SQL> CREATE TABLE  keywords (
04 #   2    kwID     INT AUTO_INCREMENT PRIMARY KEY,
05 #   3    keyword  VARCHAR(64) );
06 #
07 # SQL> CREATE TABLE  url_title (
08 #   2    urlID  INT AUTO_INCREMENT PRIMARY KEY,
09 #   3    url    VARCHAR(128),
10 #   4    title  VARCHAR(128) );
11 #
12 # SQL> CREATE TABLE  www_index (
13 #   2    kwID   INT,
14 #   3    urlID  INT,
15 #   4    PRIMARY KEY ( kwID, urlID ),
16 #   5    FOREIGN KEY ( kwID  ) REFERENCES  keywords  ( kwID ),
17 #   6    FOREIGN KEY ( urlID ) REFERENCES  url_title ( urlID ) );
18 
19 $host     = "undcemmysql.mysql.database.azure.com";
20 $username = "your_id";
21 $database = "your_db";
22 $password = "your-pw";
23 $conn     = mysqli_init( );
24 mysqli_ssl_set( $conn, NULL, NULL, "DigiCertGlobalRootCA.crt.pem", NULL, NULL );
25 mysqli_real_connect( $conn, $host, $username, $password, $database, 3306 );
26 
27 if ( $conn->connect_errno )
28   die( 'Failed to connect to MySQL: ' . $conn->connect_error );
29 
30 $sql = "DELETE FROM www_index;";
31 echo( $sql . "\n" );
32 if ( $conn->query( $sql ) == TRUE )   
33   echo "Table www_index deleted successfully\n\n";
34 else
35   echo "Error deleting table: " . $conn->error;
36 
37 $sql = "DELETE FROM keywords;";
38 echo( $sql . "\n" );
39 if ( $conn->query( $sql ) == TRUE )
40   echo "Table keywords deleted successfully\n\n";
41 else
42   echo "Error deleting table: " . $conn->error;
43 
44 $sql = "DELETE FROM url_title;";
45 echo( $sql . "\n" );
46 if ( $conn->query( $sql ) == TRUE )
47   echo "Table url_title deleted successfully";
48 else
49   echo "Error deleting table: " . $conn->error;
50 
51 # Close the database connection.
52 $conn->close( );
53 
54?>




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      — Mark Twain