Multiple mysql joins, how to combine these 2 select statments - mysql

Question

I have 2 select statements I would like to combine into one, though I really only need the info from one field in the second select statement(The field data from user_info_data). The fields I need are Firstname, lastname, email, course fullname, role, and the field data where fieldid = '15'. The first select statement will give me everything but the data field. And the second gives me everything but the course. I tried doing the second select statement similar to Role field but it complains about it returning more than one row. If I try and just use the course name without the fieldid='15' part, it brings up over 100k records(Each user shows up in each course and all their data).
Fields for tables:
user(id,auth,confirmed,policyagreed,username,password,idnumber,firstname,lastname,email,phone etc..)
user_info_data(id,userid,fieldid,data)
role(id,name,shortname,description,sortorder)
role_assignments(id,roleid,contextid,userid...)
context(id,contextlevel,instanceid,path,depth)
First statement:
SELECT user.firstname AS Firstname, user.lastname AS Lastname, user.email AS Email, course.fullname AS Course, role.name AS Role
FROM user AS user, course AS course,role,role_assignments AS asg
INNER JOIN context AS context ON asg.contextid=context.id
WHERE context.contextlevel = 50
AND role.id=asg.roleid
AND user.id=asg.userid
AND context.instanceid=course.id
Output of first stament:
Firstname Lastname Email Course Role
John Doe john.doe#email.com Course-Name Student
Second statement:
SELECT user.firstname AS 'First Name', user.lastname AS 'Last Name', user.email AS 'Email', user_info_data.data AS 'IBCLC Certified'
FROM user, user_info_data
WHERE user.id = user_info_data.userid
AND fieldid = '15'
Output of second stament:
Firstname Lastname Email IBCLC Certified
John Doe john.doe#email.com Yes
Desired Output:
FirstName,LastName,Email,IBCLC Certified,Course,Role
Other select statement I tried: Brings up 9,494 records, but right now the field data where fieldid is 15 is a list of possible choices, could that be why?
SELECT user.firstname AS Firstname, user.lastname AS Lastname, user.email AS Email, userdata.data, course.fullname AS Course, role.name AS Role
FROM user AS user, course AS course, user_info_data AS userdata, role,role_assignments AS asg
INNER JOIN context AS context ON asg.contextid=context.id
WHERE context.contextlevel = 50
AND userdata.fieldid = 15
AND role.id=asg.roleid
AND user.id=asg.userid
AND context.instanceid=course.id

Answer 1

I added user_info_data to your first request like this:
SELECT user.firstname AS Firstname,
user.lastname AS Lastname,
user.email AS Email,
course.fullname AS Course,
role.name AS Role,
ibclcCert.data AS 'IBCLC Certified'
FROM user,
course,
role,
role_assignments AS asg,
context,
user_info_data AS ibclcCert
WHERE context.contextlevel = 50
AND role.id=asg.roleid
AND user.id=asg.userid
AND context.instanceid=course.id
AND asg.contextid=context.id
AND ibclcCert.userid = user.id
AND ibclcCert.fieldid = '15'
I renamed the user_info_data table reference to something denoting the actual field, ibclcCert in this case. This renaming is a provision in case that you one day want to access more than one data field. When you do, you'd include the table multiple times, one for every field you need. See also this answer about how to deal with such data formats.