Working with Data Sources 9

标签：query   clear   bsp   cer   with   cut   condition   join   source   

1. One to many relations:

　　one value in column in table one related to several values in the column in table two. In this case, we need to be very clear that who is "one" and who is "many":

　　cursor = conn.cursor()

　　query =‘‘‘SELECT ceremonies.year,nominations.movie # select target column we want to fit into the query

　　 FROM nominations　 # select table from the ‘one‘ table

　　 INNER JOIN ceremonies #select table from the ‘many‘ table

　　 ON ceremonies.id == nominations.ceremony_id　# select revelent column

　　WHERE nominations.nominee == "Natalie Portman"; # select conditions we would like to query
　　‘‘‘　　

　　cursor.execute(query)

　　portman_movies = cursor.fetchall()

2.

Working with Data Sources 9

标签：query   clear   bsp   cer   with   cut   condition   join   source   

原文地址：http://www.cnblogs.com/kingoscar/p/6087826.html