        ____________553

. ,       -
 :

Select P.* from Pers P, Dep D WHERE (P.Dep=D.Dep)AND(D.Proisv=true)

    Pers   P,   Dep  D. ,
           -
    ,    .

  .       
. , ,       .
   

Select pi.fam, 2.fam, pl.year b FROM Pers pi, Pers p2

WHERE (pl.year_b = p2.year_b) AND (pi.fam != p2.fam)

     Pers    : 1  p2.  -
 WHERE           -
 .   pl.fam != p2.fam ,    -
      . ,   -
         , , ,
  ,     .   
       pl.Fam < p2.Fam:

Select pl.fam, p2.fam, pl.year_b FROM Pers pi, Pers p2
WHERE (pl.year_b = p2.year_b) AND

(pl.fam != p2.fam)and(pi.Fam < p2.Fam)

      1  p2  -
  .

     ,    -
   ,       
     .     -
,      ,     
 .    (outer join).   : ,  
.   (   LEFT OUTER JOIN
... ON)       ,  ,   
   .   ( 
 RIGHT OUTER JOIN ... ON)       -
,        .   (-
   FULL OUTER JOIN ... ON)   
   ,    .

, ,        Pers  
 Chef,          -
.        ,   .
  ,    Pers    
  ,     ,    . 
 Chef        ,  -
    .  

Select * FROM Pers LEFT OUTER JOIN Chef ON Pers.Fam = Chef.Fam

  :

[   Pers		  Chef
		,1
		 1...............