This can happen ever so easily. You adapt a table by adding a new column: ALTER TABLE payments ADD code NUMBER(3); You go on, implementing your business logic - absolutely no problem. But then, later on (perhaps in production), some batch job fails because it makes some strong assumptions about data types. Namely, it assumes … Continue reading How to use SQL PIVOT to Compare Two Tables in Your Database
Tag: CASE expression
How to Implement Sort Indirection in SQL
I've recently stumbled upon this interesting Stack Overflow question, where the user essentially wanted to ensure that resulting records are delivered in a well-defined order. They wrote SELECT name FROM product WHERE name IN ('CE367FAACDHCANPH-151556', 'CE367FAACEX9ANPH-153877', 'NI564FAACJSFANPH-162605', 'GE526OTACCD3ANPH-149839') They got CE367FAACDHCANPH-151556 CE367FAACEX9ANPH-153877 GE526OTACCD3ANPH-149839 NI564FAACJSFANPH-162605 They wanted CE367FAACDHCANPH-151556 CE367FAACEX9ANPH-153877 NI564FAACJSFANPH-162605 GE526OTACCD3ANPH-149839 Very often, according to your … Continue reading How to Implement Sort Indirection in SQL