Exception handling (BEGIN-EXCEPTION-END) in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start a block for exception handling in PostgreSQL.

PostgreSQL

BEGIN[1]

Drag options to blanks, or click blank then click option'

ADECLARE

BEND

CBEGIN

DEXCEPTION

Attempts:

3 left

💡 Hint

Common Mistakes

Using EXCEPTION to start the block instead of BEGIN.

Using END to start the block.

Using DECLARE to start the block.

The BEGIN keyword starts a block where you can write SQL statements and handle exceptions.

2fill in blank

medium

Complete the code to catch exceptions in a PostgreSQL block.

PostgreSQL

BEGIN
  -- some code
[1]
  WHEN others THEN
    RAISE NOTICE 'Error occurred';
END;

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AEXCEPTION

BIF

CDECLARE

DTRY

Attempts:

3 left

💡 Hint

Common Mistakes

Using TRY instead of EXCEPTION.

Using IF instead of EXCEPTION.

Using DECLARE instead of EXCEPTION.

The EXCEPTION keyword starts the exception handling section inside a block.

3fill in blank

hard

Fix the error in the exception block keyword.

PostgreSQL

BEGIN
  -- some code
[1]
  WHEN division_by_zero THEN
    RAISE NOTICE 'Cannot divide by zero';
END;

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AEXCEPTION

BEXCEPT

CCATCH

DHANDLE

Attempts:

3 left

💡 Hint

Common Mistakes

Using EXCEPT instead of EXCEPTION.

Using CATCH or HANDLE which are not valid in PostgreSQL.

The correct keyword to start exception handling in PostgreSQL is EXCEPTION. Other keywords like EXCEPT, CATCH, or HANDLE are not valid here.

4fill in blank

hard

Fill both blanks to complete the exception block that handles a unique violation error.

PostgreSQL

BEGIN
  INSERT INTO users(username) VALUES('admin');
[1]
  WHEN unique_violation THEN
    RAISE NOTICE 'Username already exists';
[2]
END;

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AEXCEPTION

BWHEN

CEND

DDECLARE

Attempts:

3 left

💡 Hint

Common Mistakes

Using WHEN to start the exception block instead of EXCEPTION.

Using DECLARE instead of EXCEPTION.

Forgetting to close the block with END.

The EXCEPTION keyword starts the exception handling section, and END closes the block.

5fill in blank

hard

Fill all three blanks to complete the exception block that handles division by zero and others.

PostgreSQL

BEGIN
  PERFORM 10 / [1];
[2]
  WHEN division_by_zero THEN
    RAISE NOTICE 'Division by zero error';
  WHEN others THEN
    RAISE NOTICE 'Some other error';
[3]
END;

Drag options to blanks, or click blank then click option'

A0

BEXCEPTION

CEND

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 instead of 0 as divisor to cause division by zero error.

Using TRY or CATCH instead of EXCEPTION.

Forgetting to close the block with END.

The first blank is the divisor which causes the error (0). The second blank starts the exception block, and the third blank ends the block.