10.33.1 Problem
The dates in your data are incomplete, that is, they have missing subparts.
10.33.2 Solution
MySQL can represent them as ISO dates using zero for the missing parts.
10.33.3 Discussion
Some applications use dates that are not complete. For example, you may need to work with input values such as Mar/2001 that contain only a month and year. As of MySQL 3.23, it's possible to represent such values as ISO-format dates that have zero in the "missing" parts. (The value Mar/2001 can be stored as 2001-03-00.) To convert month/year values to ISO format for import into MySQL, set up a hash to map month names to their numeric values:
my %map = # map 3-char month abbreviations to numeric month ( "jan" => 1, "feb" => 2, "mar" => 3, "apr" => 4, "may" => 5, "jun" => 6, "jul" => 7, "aug" => 8, "sep" => 9, "oct" => 10, "nov" => 11, "dec" => 12 );
Then convert each input value like this:
if ($val =~ /^([a-z]{3})/(d{4})$/i) { my ($m, $y) = (lc ($1), $2); # use lowercase month name $val = sprintf ("%04d-%02d-00", $y, $map{$m}) }
After storing the resulting values into MySQL, you can retrieve them for display in the original month/year format by issuing a SELECT statement that rewrites the dates using a DATE_FORMAT( ) expression:
DATE_FORMAT(date_val,'%b/%Y')
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