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SQL Set Operators

SQL Set Operators   Traditional Set Operators: Union Compatibility:     Requirement for the traditional set operators.    Strong requirement.                         - Same number of columns.                         - Each corresponding column is compatible.                         - Positional correspondence.     Apply to similar tables by removing columns first. SQL UNION Example:           Example 1: Retrieve basic data about all university people.                     SELECT FacNo AS PerNo, FacFirstName                                      ...
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You will draw an ERD diagram on ERAssistant to demonstrate certain requirements for problem (a). Then, you will extend the initial ERD for further requirements in problems (b) and (c). In problem (d), you will identify consistency errors in a given ERD diagram and redraw the ERD without the errors.

 a. Create an ERD containing the TestOrder and Specimen entity types and a 1-M relationship from Specimen to TestOrder. For each specimen collected, the database should record a unique SpecNo, SpecArea (ectocervix, cervical, or endocervical), and SpecCollMethod (thin prep or sure path). A test order contains a TONo (primary key), TOTestName, TOTestType (HPV, CT/GC, CT, or GC), and TOTestResult (positive, negative, equivocal, or failure). A specimen does not have a test order until a delay, from hours to days. If a test order produces a failure, the specimen is given a new test order and tested again until a non-failure result is obtained. A test order is created for exactly one specimen.

Answer:
Snapshot of ERD:

b. Augment your ERD from problem (a) with the Supply entity type and an M-N relationship between TestOrder and Supply. Choose a name for the relationship based on your common knowledge of test orders and supplies. A test order can use a collection of supplies (0 or more) and a supply can be used on a collection of test orders (0 or more). The Supply entity type contains SuppNo (primary key), SuppName, SuppLotNo, and SuppQOH.

Answer


c. Use the M-N equivalence rule to transform the M-N relationship in Problem (b). You should choose appropriate names for the new relationships and entity type.

Answer










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SQL Set Operators

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