SQL Check Constraint
6.Which clause removes a CHECK constraint?
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A. ALTER TABLE DROP CHECK
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B. ALTER TABLE DROP CONSTRAINT
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C. DELETE CHECK
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D. UPDATE CHECK = NULL
ALTER TABLE DROP CONSTRAINT
ALTER TABLE DROP CONSTRAINT
7.What happens?
CREATE TABLE grade (
id INT,
result CHAR(1) CHECK (result IN ('P', 'F'))
);
INSERT INTO grade VALUES (2, 'X');
-
A. Row inserted
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B. Error due to CHECK
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C. result becomes NULL
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D. result becomes 'P'
Error due to CHECK
Error due to CHECK
8.What would be the result of the below code?
CREATE TABLE salary_check (
emp_id INT,
salary INT CHECK (salary BETWEEN 10000 AND 50000)
);
INSERT INTO salary_check VALUES (1, 30000);
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A. Error
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B. Row inserted
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C. salary becomes 0
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D. NULL inserted
Row inserted
Row inserted
9.What does this mean:
CHECK (gender IN ('M', 'F'))
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A. Gender must be NULL
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B. Gender must be ‘M’ or ‘F’
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C. Gender must be numeric
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D. Gender is default
Gender must be ‘M’ or ‘F’
Gender must be ‘M’ or ‘F’
10.Can aliases be used in SELF JOIN?
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A. No
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B. Yes, required
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C. Optional
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D. Aliases not supported in SQL
Yes, required
Yes, required