Database Design for Tagging [closed]

Here’s a good article on tagging Database schemas: http://howto.philippkeller.com/2005/04/24/Tags-Database-schemas/ along with performance tests: http://howto.philippkeller.com/2005/06/19/Tagsystems-performance-tests/ Note that the conclusions there are very specific to MySQL, which (at least in 2005 at the time that was written) had very poor full text indexing characteristics.

How do I alter the position of a column in a PostgreSQL database table?

“Alter column position” in the PostgreSQL Wiki says: PostgreSQL currently defines column order based on the attnum column of the pg_attribute table. The only way to change column order is either by recreating the table, or by adding columns and rotating data until you reach the desired layout. That’s pretty weak, but in their defense, … Read more

PostgreSQL Foreign Key syntax

Assuming this table: CREATE TABLE students ( student_id SERIAL PRIMARY KEY, player_name TEXT ); There are four different ways to define a foreign key (when dealing with a single column PK) and they all lead to the same foreign key constraint: Inline without mentioning the target column: CREATE TABLE tests ( subject_id SERIAL, subject_name text, … Read more

DROP IF EXISTS VS DROP?

Standard SQL syntax is DROP TABLE table_name; IF EXISTS is not standard; different platforms might support it with different syntax, or not support it at all. In PostgreSQL, the syntax is DROP TABLE IF EXISTS table_name; The first one will throw an error if the table doesn’t exist, or if other database objects depend on … Read more

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)