Table constraints

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A table constraint is a restriction that applies to

all data values stored in a given column in a given table (this is like a domain constraint, except that the restriction does not apply to other columns based on the same domain), for example, "A person's salary may not increase by more than 5 % at a time"; or

a combination of data values in different columns of the same record, for example: "End date must be later than start date"; or

a combination of data values from multiple records within the same table or across tables, for example: "A passenger cannot participate in two tours that overlap in time".



collapseRestrictive table constraints
collapseCorrective table constraints
collapseDefining a restrictive table constraint
collapseDefining a corrective table constraint
collapseINVOKE constraints



See also

Domain constraints

Transitional constraints

Constraint messages

Constraint comments