Cursor declaration and usage in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a cursor named mycursor for selecting all rows from the employees table.

PostgreSQL

DECLARE mycursor CURSOR FOR SELECT * FROM [1];

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Aemployees

Bdepartments

Csalaries

Dprojects

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a table unrelated to employees.

Misspelling the table name.

The cursor is declared to select all rows from the employees table.

2fill in blank

medium

Complete the code to open the cursor named mycursor.

PostgreSQL

OPEN [1];

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

Acur_emp

Bcursor1

Cmycursor

Demp_cursor

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different cursor name than declared.

Forgetting to open the cursor before fetching.

The cursor named mycursor is opened to start fetching rows.

3fill in blank

hard

Fix the error in the FETCH statement to retrieve the next row from the cursor.

PostgreSQL

FETCH [1] FROM mycursor;

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Anext

Bfirst

Cprevious

Dlast

Attempts:

3 left

💡 Hint

Common Mistakes

Using FETCH FIRST or FETCH LAST which do not fetch the next row.

Using FETCH PREVIOUS which moves backward.

The FETCH NEXT statement retrieves the next row from the cursor.

4fill in blank

hard

Fill both blanks to declare and open a cursor named emp_cursor selecting employee_id and name from employees.

PostgreSQL

DECLARE [1] CURSOR FOR SELECT employee_id, name FROM employees;
OPEN [2];

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

Aemp_cursor

Bmycursor

Ccursor_emp

Demployee_cur

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for declaration and opening.

Misspelling the cursor name.

The cursor is declared and opened using the same name emp_cursor.

5fill in blank

hard

Fill all three blanks to fetch the first row from cursor emp_cursor into variables emp_id and emp_name.

PostgreSQL

FETCH [1] FROM emp_cursor INTO [2], [3];

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

Anext

Bemp_id

Cemp_name

Dfirst

Attempts:

3 left

💡 Hint

Common Mistakes

Using FETCH NEXT instead of FETCH FIRST.

Swapping variable names or using undeclared variables.

The FETCH FIRST statement retrieves the first row, storing values into variables emp_id and emp_name.