MYSQL JOIN WHERE ISSUES - need some kind of if condition

Well this will be hard to explain but ill do my best

The thing is i have 4 tables all with a specific column to relate to eachother. 1 table with users(agent_users) , 1 with working hours(agent_pers), 1 with sold items(agent_stat),1 with project(agent_pro) the user and the project table is irrelevant in the issue at hand but to give you a better understanding why certain tables is included in my query i decided to still mention them =) The thing is that I use 2 pages to insert data to the working hour and the sold items during that time tables, then i have a third page to summarize everything for current month, the query for that is as following:

SELECT *, SUM(sv_p_kom),SUM(sv_p_gick),SUM(sv_p_lunch) FROM ((
agent_users 
LEFT JOIN agent_pers ON agent_users.sv_aid = agent_pers.sv_p_uid) 
LEFT JOIN 
agent_stat ON agent_pers.sv_p_uid = agent_stat.sv_s_uid) 
LEFT JOIN 
agent_pro ON agent_pers.sv_p_pid=agent_pro.p_id
WHERE MONTH(agent_pers.sv_p_datum) =7 GROUP BY sv_aname

so the problem is now that i dont want sold items from previous months to get included in the data received, i know i could solve that by simple adding in the WHERE part MONTH(agent_stat.sv_s_datum) =7 but then if no items been sold that month no data at all will show up not the time or anything. Any aid on how i could solve this is greatly appreciated. if there's something that's not so clear don开发者_如何转开发t hesitate to ask and ill try my best to answer. after all my english isn't the best out there :P regards breezer

Fair enough :) -- put the condition as a second condition in your JOIN clause. ON (agent_pers.sv_p_uid = agent_stat.sv_s_uid AND agent_stat.sv_s_datum = 7)

Is your data such that you could add (MONTH(agent_stat.sv_s_datum) =7 OR agent_stat.sv_s_datum IS NULL) to the WHERE clause?