multiple clauses with mysql

left_join_with_mysql_view.sql

SELECT 
    T0.client_id, name, exts, vms, ivrs, queues, conf10, conf20, conf30
FROM 
    vw_clients T0
    left join  vw_exts T1 on T0.client_Id=T1.client_id
    Left join  vw_vms T2 on ...
    ...
Where ...

multiple_clause_with_count.sql

SELECT 
    SUM(category='x') as tot_x, 
    SUM(category='y') as tot_y, 
    SUM(category='z') as tot_z 
FROM table
WHERE cid='290463' and category in ('x', 'y', 'z')