$1.(15$ points $=5$ x $3$pts$)$ Referential Integrity Constraints: Firstly, specify the referential integrity constraints $($foreign key $$ primary key$).$ To do this, use the notation in the following example: ORDER.Custno $$ CUSTOMER $($Here$,$ Custno in the ORDER table is a foreign key and it refers IMPLICITLY to the primary key Custno in the CUSTOMER table$)$

$2.(40$ points$)$ Referential Triggered Actions: Secondly, choose and describe $($using the SQL syntax$),$ the appropriate action $($reject$,$ cascade, set to NULL, or set to default$)$ for each referential integrity constraint, both

i$.(20$ points $=5$ x $4$pts$)$ For deletion of a referenced tuple, and

ii$.(20$ points $=5$ x $4$pts$)$ For update of a primary key attribute value in a referenced tuple.

$3.(30$ points $=6$ x $5$ pts$)$ Write appropriate SQL DDL statements for declaring the ORDER$-$PROCESSING relational DB schema $($shown at the end of this handout$).$ Specify in SQL the attributes, their data type, the primary keys, the