sql - Alternative to nested select statements -

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i have following tables structure:

enter image description here

currently filtering users implemented pretty complex nested sql query (moreover automatically generated linq). looks approximately like:

select (select (select ( infinity here...))))

is there way simplify filtering process?

please, take account there different characteristic types. here sub-queries conditions samples:

... cv.text '%aaa%' , c.id = 5 ... cv.imageid not null , c.id = 10 ... cv.number > 5 , c.id = 33

etc...

will appreciate , ideas(change db structure, change technology, etc...), thanks!

as describing it, query should this

select u.id users u     exists (         select *         characteristicvalues cv         cv.text '%aaa%' , cv.characteristicid = 5 , u.id = cv.userid     ) ,      exists (         select *         characteristicvalues cv         cv.imageid not null , cv.characteristicid = 10 , u.id = cv.userid     ) ,      exists (         select *         characteristicvalues cv         cv.number > 5 , cv.characteristicid = 33 , u.id = cv.userid     )

or even

    select distinct cv.userid     characteristicvalues cv     cv.text '%aaa%' , cv.characteristicid = 5      union      select distinct cv.userid     characteristicvalues cv     cv.imageid not null , cv.characteristicid = 10      union      select distinct cv.userid     characteristicvalues cv     cv.number > 5 , cv.characteristicid = 33

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