MySQL Inner Join Query: incorrect output -

i have mysql query , using inner join in query. due unknown reason not working expected. not sure wrong query. can advise me doing wrong.

here query.

select f.uid, a.uid, b.uid, c.uid,        d.uid, e.uid,        f.date, a.email, a.fname, a.lname,        a.mobile, a.pic, a.address   users  inner join friends b  inner join exp c  inner join skill d  inner join personaldetails e  inner join jobs f      on a.uid = b.uid =c.uid = d.uid=e.uid=f.uid  f.job_id= 22      , f.ignored=0      , a.fname '%rah%'  order f.date desc 

if run query suppose a.uid =1, b.uid =1, c.uid =1, d.uid=1, f.uid =1

but getting a.uid =1, b.uid=10, c.uid=10, d.uid=1,e.uid=1,f.uid =1

it seems weird issue, i've tried below.

select 1=10=10=1=1=1 dual; 

result 0,

select 10=10=1=1=1=1 dual; 

result 1, maybe on a.uid = b.uid =c.uid = d.uid=e.uid=f.uid query condition take second 1 compute result. i'm not sure if mysql kind of optimized step cause issue when excuting.

i think when mysql compute a.uid = b.uid if a.uid , b.uid both 1, comes out value 1 means true, if c.uid 1 computing go on d.uid, e.uid, f.uid.

anyway, try this, may you;)

select f.uid, a.uid, b.uid, c.uid,    d.uid, e.uid,    f.date, a.email, a.fname, a.lname,    a.mobile, a.pic, a.address users a, friends b ,exp c, skill d, personaldetails e, jobs f   f.job_id= 22  , f.ignored=0  , a.fname '%rah%' , a.uid = b.uid , b.uid = c.uid , c.uid = e.uid , e.uid = f.uid  order f.date desc 

if you've found other explanation, share me plz;)