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Referential Integrity
eferential integrity is applied in databse to maintain accuracy and consistency of data in a relationship
between tables. When data is linked between two or more tables with the help of primary key and foreign
key constraints this rule helps:
Adding more records to a related child table if there is no associated record available in the table where
primary key is defined in the parent table.
hanging values in a primary key table will also reflect in dependent records present in associated table s .
Deleting records from a primary key table if there are any matching related records available in associated
child table s .
Lab Assignment ‘n Activity S ub j e ct E nr ich me nt
Complete the following activities and tick on the circle.
reate a atabase namely Student having a able Stumast with the following fields:
Field Name Field Type
Stu I Number N M I
Stu Name ext
ender ext
lass ext
Sec ext
oll No Number N M I
a pply proper validation in all the fields. ike ntry e uired ength efault alue .
b reate another table namely arents to store parents details with fields Stu I
Number N M I Fname ext Mname ext .
c Set Stu I as primary key in both the ables.
d dd atleast records in both the ables.
e Set elationship between both the ables.
f Modify Stu I of the last record as in Stumast able and see if the Stu I of the last
record of arents table changed or not.
g elete one record from the Stumast able and see if the same Stu I is deleted from
the arents table or not.
QUERY
In database, query is a tool through which data is evaluated or manipulated and reports are generated. A
user can apply a filter criteria in uery so that only those records which meet the criteria are evaluated and
displayed. In ase there are three ways to generate a uery.
reate uery in esign iew...
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