The structure design of the station inner letter table

The structure design of the station inner letter table A person can point to dots point to mass but both sides can choose whether to delete and the administrator can see all the table structure design

Create TableMessage_sender (MidintUnsigned not NULL Primary KeyAuto_increment Comment'self-increment ID in station letter', From_uidintUnsigned not NULL default 0Comment'Sender ID', From_usernamevarchar( -) not NULL default "'Comment'Name of Sender', titlevarchar( $) not NULL default "'Comment'Information Title', Contenttext  not NULLComment'Information Content', from_deletedtinyintUnsigned not NULL default 0Comment'deleted by Sender', Date_timeintUnsigned not NULL default 0Comment'Sending Time') CharSet UTF8 comment'User station letter delivery form';Create Tablemessage_receiver (RIDintUnsigned not NULL Primary KeyAuto_increment Comment'self-increment ID', MidintUnsigned not NULL default 0Comment'associated Station Letter ID', To_uidintUnsigned not NULL default 0Comment'Recipient ID', To_usernamevarchar( -) not NULL default "'Comment'name of the person receiving the letter', is_readedtinyintUnsigned not NULL default 0Comment'whether the addressee is reading', is_deletedtinyintUnsigned not NULL default 0Comment'is deleted by the addressee',) CharSet UTF8 comment'User station internal letter receiving table';

The structure design of the station inner letter table