While working on a web links directory i wanted to update categories table’s num_listings column with the count of listings under each category. The category id was stored something like this in listings table:
Tag: mysql joins
A few notes on joining a MySQL table to itself to get unique combination of field data
Just a few notes on joining a MySQL table to itself to get unique combination of data stored in its fields. Suppose we have a MySQL table named `keywords` having fields `word1`, `word2` and `word3`. Once we have got a…