Tagged Questions
2
votes
1answer
33 views
How to read this output from MySQL?
Query that is being ran:
INSERT INTO `log_url` (`url_id`, `visitor_id`, `visit_time`) VALUES (?, ?, ?)
Error that is being thrown:
SQLSTATE[23000]: Integrity constraint violation: 1062 ...
0
votes
1answer
26 views
Check for records that break a foreign constraint (created with foreign_key_checks = 0)?
Is there an easy way to check for any records in a table that breaks any constraint?
The constraint was created on a populated table using "foreign_key_checks=0".
3
votes
2answers
107 views
Finding violations of the symmetry constraint
Suppose I have a table Friends with columns Friend1ID, Friend2ID. I chose to represent each friendship with two records, say (John, Jeff) and (Jeff, John). Thus, each pair of friends should show up ...
5
votes
2answers
189 views
How should an object that can reference an object of multiple types be modeled in a relational schema?
Apologies for the obscure question, it may make more sense with a concrete example:
In my application, I may create a portfolio that contains a set of projects. However, I may also add a ...
