Constraint example sentences

A relational database schema is a set of relation schemas and a set of integrity constraints.However, in recent years the rise of coalition politics has imposed certain constraints on the power of the Prime Minister.But in any case, it is a constraint that does not allow any two-entity instances from having the same value for the key attribute at a point of time.The insert operation is capable of violating any of the four constraints discussed above.But remember that there is a basic constraint in raising farm production.A relational database state is a set of relation states such that every relational database state satisfies the integrity constraints specified on relational database schema.Retrieval operation on Relational Data Model does not cause violation any integrity constraints.This can be shown diagrammatically as shown in figureure 1 2 Therefore, minimal super-key (also called Key) is defined as that part of super-key from which any attribute cannot be removed without sacrificing the uniqueness constraint.While key and entity constraints are specified on individual relation, the referential integrity constraint is specified between two or more relations.Each of these models, which consist of a set of relations (or tables) and the integrity constraints, constitutes the database design for accounting.Whenever applied, these operations must enforce integrity constraints specified on relational database schema.DBMS software is used to implement the data model by creating several tables, setting their interrelationships and imposing constraints as may be set out in database design.The Integrity constraints, specified on database schema, must hold in every database state of that schema.Besides this, it has the capability to define useroriented views of database, specify security and authorisation, define integrity constraints and various other operations.The referential integrity constraint stands violated in above example, if there is a debit or credit code in voucher relation, the tuple for which does not exist in Accounts relation.