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Question
SQL views are always updatable when ________.A) the view is based on a single table with no computed columns, and all non-null columns are present in the view
B) the view is based on any number of tables, with or without computed columns, and the INSTEAD OF trigger is defined for the view
C) the view is based on multiple tables, the update is being done on the most subordinate table, and the rows of that table can be uniquely identified
D) Both A and B are correct
Answer
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Related questions
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Suppose you have created a data model for an airline based on a variety of forms, reports, user interviews, data sources, etc. Your client comes forward with a new desired report that includes passenger weights and a relationship between passengers and employees, neither of which is in your E-R diagram. You should ________.
A) create a new, separate E-R diagram with just the new information
B) add the relationship and the weight attribute to the existing data model
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ID-dependent entities are a common type of weak entity.
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Q:
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Q:
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B) limits the number of rows retrieved from a table
C) limits the number of tables retrieved from a database
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Q:
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A) relationships
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Q:
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Q:
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