union not working empty results - mysql

Question

I tried using inner join and union not working
sql="SELECT * FROM " +
"(SELECT order_id, order_date, order_status, order_value, order_sapId, order_from, order_clientAcct, order_error, order_visitId, order_cancelled, distributor_name " +
" FROM `orders` " +
" JOIN visits on visit_id = order_visitId " +
" JOIN Name ON user_id = visit_userId " +
" JOIN distributor ON distributor_id = visit_outlet_id " +
" WHERE order_from = 'CSFA' AND user_id = '"+ App.getUserData("user_id")+"' " +
")" +
" JOIN " +
"(SELECT order_id, order_date, order_status, order_value, order_sapId, order_from, order_clientAcct, order_error, order_visitId, order_cancelled, distributor_name " +
" FROM `orders` " +
" JOIN distributor ON order_clientAcct = distributor_accountName " +
" JOIN user ON salesEmpNo = user_sapId " +
" WHERE order_from = 'u' AND user_id = '"+ App.getUserData("user_id")+"' " +
") " +
"" +
"ORDER BY order_id DESC LIMIT 100" +
"";
I need a way to join the two results
1. tried inner join
2.tried union
E/SQLiteLog: (1) near "(": syntax error
11-24 19:53:01.017 13531-13531/E/AndroidRuntime: FATAL EXCEPTION: main
Process: , PID: 13531
android.database.sqlite.SQLiteException: near "(": syntax error (code 1): , while compiling: SELECT * FROM (SELECT order_id, order_date, order_status, order_value, order_sapId, order_from, order_clientAcct, order_error, order_visitId, order_cancelled, distributor_name FROM orders JOIN visits on visit_id = order_visitId JOIN Name ON user_id = visit_userId JOIN distributor ON distributor_id = visit_outlet_id WHERE order_from = 'CSFA' AND user_id = '75' ) UNION (SELECT order_id, order_date, order_status, order_value, order_sapId, order_from, order_clientAcct, order_error, order_visitId, order_cancelled, distributor_name FROM orders JOIN distributor ON order_clientAcct = distributor_accountName JOIN user ON salesEmpNo = user_sapId WHERE order_from = 'u' AND user_id = '75' ) ORDER BY order_id DESC LIMIT 100
That is the error log

Answer 1

after days of research finally got an answer .Used LEFT JOIN and OR to get data from table only where they match.
sql="" +
"SELECT DISTINCT order_id, order_date, order_status, order_value, order_sapId, order_from, order_clientAcct, order_error, order_visitId, order_cancelled, distributor_name " +
" FROM `orders` " +
" LEFT JOIN visits,user,distributor ON (visit_id = order_visitId AND user_id = visit_userId AND distributor_id = visit_outlet_id AND order_from = 'CSFA' AND user_id = '"+ App.getUserData("user_id")+"') OR " +
" " +
" ( order_clientAcct = distributor_accountName AND salesEmpNo = user_sapId AND order_from = 'SAP' AND user_id = '"+ App.getUserData("user_id")+"' )" +
" " +
"ORDER BY order_id DESC LIMIT 100" +
"";