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CHECK Constraints in SQL
A CHECK constraint is a table constraint defined using the key word CHECK, as already illustrated in several examples in this chapter. In particular, a CHECK constraint can be used to express a constraint such as the one shown in Example, referred to in the theory book as a tuple constraint (so one might call it a row constraint in SQL). This is clearly the way most SQL users would prefer to express such a constraint.
Use of Table Expressions - Expressing Constraint Conditions With the exception of key constraints, the examples in the theory book all explicitly reference at least one relvar
Using the BULK COLLECT Clause The keywords BULK COLLECT specify the SQL engine to bulk-bind output collections before returning them to the PL/SQL engine. You can use these ke
What are 3 good practices of modeling and/or implementing data warehouses?
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Effects of NULL Operator As a general rule-but not a universal one-if NULL is an argument to an invocation of a system-defined read-only operator, then NULL is the result of t
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