Posts about "Programació"
Optimizing MySQL subqueries
Yesterday I was writing some SQL queries involving subqueries for a MySQL database when I saw it were being executed very poorly. This is an example of how it looked:
SELECT * FROM country WHERE id IN (
SELECT country_id FROM province WHERE id = 123
)
Nothing complicated over here... (more)
Guardar números a la base de dades
Un error freqüent quan definim les columnes d'una taula (o creem una variable) és no escollir el tipus correcte per les que contenen números. El primer comentari de l'entrada Why SSN should NOT be stored as an integer in a database dóna un parell de regles ben senzilles per no cagar-la:
... (more)
