Description: twitter can be seen as a micro blog, its basic structure from the publisher and the composition of the follower. Design the form as follows:
user (uid, uname, rank), initially rank = 0 follow (idol, fan), said the fan following of the idol message (msg_id, uid, msg_content), store all the news published, uid is the message publisher identity.
Use the trigger to complete the following functions: When the message table to insert new messages, the search follow the table, to the message sent to it the formation of those fans, of course, as long as the display "******* received the message" can .
Also use triggers to maintain user in the table rank, rank = (number of users to publish news of the fans* The number of users)/100, of course, you can give a more precise definition.
File list (Check if you may need any files):
触发器.sql
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