506  9

    .      Min-
Value   Value,       -
. ,         
  ,     Year_b  
Min Value = 1970  MaxValue = 1980.      -
 .         
      .   
  ,   . 5.29.    
    .    -
    (.  4.9.3.2  4)   
  -.

. 5.29

     
   
 MinValue  MaxValue

      CustomConstraint
 ConstraintErrorMessage.  CustomConstraint   -
       SQL (.  10.1). ,  
  Year_b      CustomConstraint:

 < I960 and X > 1970

  (      X)   -
.

    CustomConstraint,     
ConstraintErrorMessage.    ,    
  ,    ,   
. ,       (.
. 5.30,       ).  ,  -
     MinValue  MaxValue,   
 .          
.

. 5.30

      
   
CustomConstraint  ConstraintErrorMessage

          -
   On Validate.      
     .     -
,        , -
,   EAbort  Abort.   ,
   OnValidate    OnChange,   -
      .

        .
       , 
  .     Constraints  Table. -
    ,     ,  
. 9.31.      Add New ( )    
 Constraints  .      -