We have a table that we use to store answers to questions. We need to be able to find users that have certain answers to particular questions. So, if our table consists of the following data: user_id ...
I've been asked in my job to violate the first normal form (repeating groups across columns, using empty / null values) several times, "for the sake of computer processing power". In a nutshell, a ...
There are two instances of DB2 running on the same machine. One has a table aliased to the a table in the other one. Is there a way to do this in DB2 or does it have to be done via an external tool? ...
I have seen the following in a query that was supposed to be ported from Oracle outer join syntax to SQL standard outer join syntax: SELECT ... FROM A, B, C, D, E WHERE A.A_ID = B.A_ID AND B.B_ID = ...
Are there any database engines which will intuit the join condition based on the existing foreign keys?
It seems strange to me that, when I've defined a foreign key, the engine cannot use this information to automatically figure out the correct JOIN expressions, but instead requires me to re-type the ...
I am new to SQL and wanted to know what is the difference between those two JOIN types? SELECT * FROM user u INNER JOIN telephone t ON t.user_id = u.id SELECT * FROM user u LEFT OUTER JOIN ...
I've been wanting to use joins for a while, but I'm having trouble visualizing the output so I know how to put it to use. Let's say I have 2 tables: CREATE TABLE Cities ( id INT UNSIGNED PRIMARY ...