Conditionally limit MySQL SELECT query My goal is to select rows from a mysql table, but according to certain column. Normal SELECT would be:

        SELECT
        ti.id, ti.userid, ti.date, ti.duedate, ti.datepaid, ti.subtotal, ti.taxrate, ti.paymentmethod, ti.notes AS invoicenotes,
        tii.invoiceid, tii.type, tii.description, tii.amount,
        tc.id, tc.firstname, tc.lastname, tc.companyname, tc.email, tc.address1, tc.address2, tc.city, tc.state,
        tc.postcode, tc.country, tc.phonenumber, tc.currency, tc.defaultgateway, tc.credit, tc.taxexempt,
        tc.latefeeoveride, tc.overideduenotices, tc.separateinvoices, tc.disableautocc, tc.datecreated,
        tc.notes AS tcnotes,
          (SELECT GROUP_CONCAT(value) FROM tblcustomfieldsvalues WHERE relid=tc.id) AS vatid
        FROM tblinvoices ti
        LEFT JOIN tblinvoiceitems tii
        ON tii.invoiceid=ti.id
        LEFT JOIN tblclients tc
        ON tc.id=tii.userid
        WHERE ti.status='Paid'
        AND ti.infakt_no IS NULL
        AND ti.paymentmethod='transferuj'
        ORDER BY ti.userid AND tii.id


But that kind of SELECT would split rows with same userid value. How to SELECT certain amount of rows and keep from separating userid?
What i understand from your question is you need to group your result on the basis of user_id for that you can try this one

SELECT user_id,GROUP_CONCAT(id),GROUP_CONCAT(content) FROM tbl WHERE sth='sth' GROUP BY user_id LIMIT 10;


If you need anything else please comment and update in your question.