17.2.1 Problem
You want to display a query result as free text.
17.2.2 Solution
Display it with no surrounding HTML structure other than paragraph tags.
17.2.3 Discussion
Paragraphs are useful for displaying free text with no particular structure. In this case all you need to do is retrieve the text to be displayed, encode it to convert special characters to the corresponding HTML entities, and wrap each paragraph within
and
tags. The following examples show how to produce a paragraph for a status display that includes the current date and time, the server version, the client username, and the current database name (if any). These values are available from the following query:
mysql> SELECT NOW( ), VERSION( ), USER( ), DATABASE( ); +---------------------+-----------------+----------------+------------+ | NOW( ) | VERSION( ) | USER( ) | DATABASE( ) | +---------------------+-----------------+----------------+------------+ | 2002-05-18 11:33:12 | 4.0.2-alpha-log | paul@localhost | cookbook | +---------------------+-----------------+----------------+------------+
In Perl, the CGI.pm module provides a p( ) function that adds paragraph tags around the string you pass to it. p( ) does not HTML-encode its argument, so you should take care of that by calling escapeHTML( ):
($now, $version, $user, $db) = $dbh->selectrow_array ("SELECT NOW( ), VERSION( ), USER( ), DATABASE( )"); $db = "NONE" unless defined ($db); $para = <
In PHP, you can print the
and
tags around the encoded paragraph text:
$query = "SELECT NOW( ), VERSION( ), USER( ), DATABASE( )"; $result_id = mysql_query ($query, $conn_id); if ($result_id) { list ($now, $version, $user, $db) = mysql_fetch_row ($result_id); mysql_free_result ($result_id); if (!isset ($db)) $db = "NONE"; $para = "Local time on the MySQL server is $now." . " The server version is $version." . " The current user is $user." . " The current database is $db."; print ("
" . htmlspecialchars ($para) . "
"); }
Or, after fetching the query result, you can print the paragraph by beginning in HTML mode and switching between modes:
Local time on the MySQL server is . The server version is . The current user is . The current database is .
To display a paragraph in Python, do something like this::
cursor = conn.cursor ( ) cursor.execute ("SELECT NOW( ), VERSION( ), USER( ), DATABASE( )") row = cursor.fetchone ( ) if row is not None: if row[3] is None: # check database name row[3] = "NONE" para = ("Local time on the MySQL server is %s." + " The server version is %s." + " The current user is %s." + " The current database is %s.") % (row) print "
" + cgi.escape (para, 1) + "
" cursor.close ( )
In JSP, the display might be produced as follows:
SELECT NOW( ), VERSION( ), USER( ), DATABASE( )
Local time on the server is . The server version is . The current user is . The current database is .
The JSP script uses rowsByIndex so that the result set row's columns can be accessed by numeric index.
Using the mysql Client Program
Writing MySQL-Based Programs
Record Selection Techniques
Working with Strings
Working with Dates and Times
Sorting Query Results
Generating Summaries
Modifying Tables with ALTER TABLE
Obtaining and Using Metadata
Importing and Exporting Data
Generating and Using Sequences
Using Multiple Tables
Statistical Techniques
Handling Duplicates
Performing Transactions
Introduction to MySQL on the Web
Incorporating Query Resultsinto Web Pages
Processing Web Input with MySQL
Using MySQL-Based Web Session Management
Appendix A. Obtaining MySQL Software
Appendix B. JSP and Tomcat Primer
Appendix C. References