COMPUTER SCIENCE AND ENGINEERING
SQL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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How many records will the following SQL statement produce?SELECT Dept ____ ID, Title ____ IDFROM Department, JobTitle;
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5
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13
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18
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65
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Explanation:
Detailed explanation-1: -COUNT(*) with GROUP BY returns the number of rows in each group. This includes NULL values and duplicates. COUNT(ALL <expression>) evaluates expression for each row in a group, and returns the number of nonnull values.
Detailed explanation-2: -In SQL, you can make a database query and use the COUNT function to get the number of rows for a particular group in the table. Here is the basic syntax: SELECT COUNT(column name) FROM table name; COUNT(column name) will not include NULL values as part of the count.
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