SQL tips and tricks

Over a period of time we have accumulated a large number of SQL tips and tricks. This is a collection of those quirks. Generic SQL, MSSQL, MySQL & PostgreSQL are included.   To find all the rows in a table where a certain value is empty select productid,title_tag,weight,length,width,height,meta_description from xcart_products where LENGTH(meta_description) != 0″ queries…