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MySQL Cookbook
book

MySQL Cookbook

by Paul DuBois
October 2002
Intermediate to advanced content levelIntermediate to advanced
1024 pages
27h 26m
English
O'Reilly Media, Inc.
Content preview from MySQL Cookbook

Performing Date Conversion Using SQL

Problem

You want to convert dates using SQL statements.

Solution

For export, use the DATE_FORMAT( ) function to rewrite the values. For import, read the values into a string column and convert them to true DATE values.

Discussion

Suppose you want to export data from MySQL into an application that doesn’t understand ISO-format dates. One way to do this is to export the data into a file, leaving the dates in ISO format. Then run the file through some kind of utility like cvt_date.pl that rewrites the dates into the required format.

Another approach is to export the dates directly in the required format by rewriting them with DATE_FORMAT( ). Suppose you need to export data from a table, but with the dates written in U.S. (MM-DD-CCYY) format. The following script can accomplish this. It takes the names of a database and table as its arguments, then dumps the table in tab-delimited format with the dates in any DATE, DATETIME, or TIMESTAMP columns reformatted. The script does this by examining the table metadata to get the column types, then constructing a SELECT statement that uses DATE_FORMAT( ) to rewrite the dates. Other columns in the table are written without change:

#! /usr/bin/perl -w # iso_to_us.pl - Export a table with dates rewritten from ISO format # (CCYY-MM-DD) to U.S. format (MM-DD-CCYY). This is done by generating a # SELECT statement that selects all the columns of the table, but uses # DATE_FORMAT( ) to rewrite the dates. # Writes each ...
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Publisher Resources

ISBN: 0596001452Catalog PageErrata