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Posts Tagged ‘MySQL’

MYSQL ALTER Statement for TIMESTAMP Column to Change on Update

January 7th, 2011 Comments off

If you need to alter a TIMESTAMP column to update the column automatically when the contents of the row are changed, run the following MySQL ALTER statement against the table: Read more…

Categories: MySQL Tags: , ,

Quickly duplicating MySQL table structures

May 1st, 2009 Comments off

I often find myself duplicating table structures to either do some testing or duplicating a database structure from one database to another. Most of the time,  I find that I do not need to copy the existing data to the new database table. The easiest way I have found to do this is using MySQL’s CREATE TABLE…LIKE… () syntax. Even the most basic form can fulfill most requirements. This form could be something like:

CREATE TABLE `bar` LIKE `foo`;

For the MySQL 5.1 reference page, go here:  http://dev.mysql.com/doc/refman/5.1/en/create-table.html

Categories: MySQL Tags: ,

Downloading and Converting EWS BulkDownload TSV Files

April 28th, 2009 Comments off

For the longest time, I avoided using the BulkDownload service of Yahoo’s Enterprise Web Services (EWS) for managing our daily pay per click (PPC) account. Now this wasn’t because I did not want to use it, I just thought it was was going to be a severe pain to get it implemented. The reasoning for my hesitation in implementing the BulkDownload feature was because I was pretty ignorant to different encodings. Now that my knowledge of encoding types has blossomed over time, I felt I was ready to tackle the project of using and implementing Yahoo’s BulkDownload service in a complete daily account synchronization for avery large PPC account structure.

When using Yahoo’s EWS BulkDownload service, you can request one of two file formats to be returned to you. These two file formats are:

  • EXCEL_XML – an Excel 2003 XML format
  • TSV (tab seperated value)

Here is the trickey part: the EXCEL_XML files are UTF-8 encoded and the TSV files are returned in UTF-16LE encoding.  Normally, I like to use comma seperated value (CSV) file formats and use the LOAD DATA [LOCAL] INFILE  syntax of MySQL. (One can just as easily use TSV file formats with the LOAD DATA [LOCAL] INFILE syntax. You just need to make sure you specify

FIELDS TERMINATED BY '\t'

instead of

FIELDS TERMINATED BY ','

in your SQL statement.) Bacause of the TSV file coming in as UTF-16LE encoded, simply grabbing the tab seperated value file and loading it right into MySQL would not work. My solution would just involved a couple extra steps; once I retrieved the account structure file from Yahoo, I would simply loop back through the file and convert the data of the file from ‘utf-16′ to ‘ascii’ using PHPs iconv() function. This can obviously be done in multiple ways, but here would be one way to accomplish the task:

while (!feof($handleIn))
 {
    $content = iconv('utf-16', 'ascii', fread($handleIn, 8192));
    fwrite($handleOut,$content);
 }

Once the file has been successfully converted over to ascii, I can then run a LOAD DATA [LOCAL] INFILE to get the TSV file into a MySQL table:

LOAD DATA local INFILE '[file_name]'
INTO TABLE [table_name]
FIELDS TERMINATED BY '\t' optionally ENCLOSED BY '\"' LINES TERMINATED BY '\n'
IGNORE 2 LINES;

The reason for the IGNORE 2 LINES is because the first two lines of TSV file are basically header rows and I consider them to be junk rows.

Selecting a result set into a Comma Seperated Value (.csv) file

April 14th, 2009 Comments off

Getting a result set from MySQL into a comma seperated value (.csv) file does not have to be a difficult adventure.  In the past, I might have written my query in SQLyog, select the query, hit F9 to run the query, and click on the button to Copy All Rows to Clipboard, paste the copied results into an Excel spreadsheet and save the Excel spreadsheet at a .csv file. Trust me though, there is a better way!

To save a result set into a .csv file from your query, check out MySQL’s SELECT…INTO OUTFILE syntax. In the following example, I want to create a comma seperated value file that contains a list of all cities in the state of Michigan from my cities table. The syntax to do so, on my Windows machine, would look like:

SELECT     city, state_abbrev, country_code
INTO OUTFILE 'C:\temp\cities.csv'
    FIELDS TERMINATED BY ','
    OPTIONALLY ENCLOSED BY '"'
    LINES TERMINATED BY '\n'
FROM     cities
WHERE     state_name = 'Michigan'
ORDER BY city ASC

To get more information on this nifty feature of MySQL, check out the SELECT…INTO OUTFILE manual page (http://dev.mysql.com/doc/refman/5.0/en/select.html) at mysql.org