Tag: databases

Questions Related to databases

Identify the correct output --- select LAST_DAY(TO_DATE('01-SEP-1995', 'DD-MON-YYYY')) from dual;
technology databases

  1. 31-AUG-1995

  2. 30-SEP-1995

  3. 31-OCT-1995

  4. 31-DEC-1995

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Correct Option: B

Which functions mentioned below are GROUP functions? Choose all that apply
technology databases

  1. ADD_MONTHS

  2. COUNT

  3. ROUND

  4. DISTINCT

  5. AVG

  6. SUM

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Correct Option: B,E,F

WHERE clause is used to restrict groups

technology databases

  1. True

  2. False

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Correct Option: B

One can NOT delete a row from the VIEW if view definition contains ... Choose all that apply
technology databases

  1. WHERE clause

  2. GROUP BY clause

  3. GROUP functions

  4. DISTINCT keyword

  5. FROM clause

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Correct Option: B,C,D

An application developer wants to query row count of a table, ORDERS which has millions of records. ORDERS table has composite PRIMARY KEY on (ORDER_ID, CUSTOMER_ID) columns and those two columns appear at position 1 and 2 respectively in the ORDERS table. Which query will be more efficient?

technology databases

  1. select count(*) from orders;

  2. select count(1) from orders;

  3. select count(3) from orders;

  4. select count(5) from orders;

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Correct Option: B

Identify the MANDATORY sections of a PL/SQL block
technology databases

  1. DECLARE

  2. BEGIN

  3. EXCEPTION

  4. END

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Correct Option: B,D

%ROWTYPE attribute is used to declare a variable and associate it's data type with the TABLE/CURSOR object.
technology databases

  1. True

  2. False

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Correct Option: A

Within a PL/SQL block, which commands are allowed? Choose all that apply
technology databases

  1. SELECT

  2. CREATE

  3. DELETE

  4. DROP

  5. UPDATE

  6. INSERT

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Correct Option: A,C,E,F

INSERT, UPDATE, DELETE commands when used in a PL/SQL block, should contain INTO clause to hold the data returned by SQL statement
technology databases

  1. True

  2. False

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Correct Option: B

IF-THEN-ELSE-ENDIF construct is used for conditional control in a PL/SQL block. What happens if the condition in IF-THEN-ELSE-ENDIF block evaluates to NULL?
technology databases

  1. The SQL statements in the IF condition are processed.

  2. The SQL statements in the ELSE condition are processed.

  3. IF-THEN-ELSE-ENDIF construct is skipped.

  4. The SQL statements in the IF condition as well as ELSE condition are processed.

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Correct Option: C