CBSE Class 12 Sample Paper for 2023 Boards

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Computer Science - Class 12
Solutions to CBSE Sample Paper - Computer Science Class 12

Question 25 (Choice 1) - CBSE Class 12 Sample Paper for 2023 Boards - Solutions to CBSE Sample Paper - Computer Science Class 12

Last updated at April 16, 2024 by

Differentiate between count() and count(*) functions in SQL with appropriate example.

 

Answer:

COUNT( )

COUNT(*)

Always used with a column name passed as argument and returns the count of the number of rows with non-null values in the column given as argument.

Returns the count of all rows in the table.

 

Example:

Question 25 Example 1 -Teachoo.png

COUNT DEPT NAME return 4 -Teachoo.png

COUNT DEPT NAME return 5 -Teachoo.png

  • COUNT(*) returns 5 since there are 5 records in the table DEPARTMENT.
  • COUNT(DEPT_NAME) return 4 since there is 1 null value in the column DEPT_NAME.
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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo