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Answer: Aggregate Records Using COUNT

Answer: Aggregate Records Using COUNT

Find a detailed explanation of using the COUNT function to aggregate records in a table using SQL query.

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Solution

The solution is given below:

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/* The query to find the count of exams missed */
SELECT COUNT(*) AS AbsentStudents
FROM   StudentGrades
WHERE  Marks IS NULL;

Explanation

The explanation of the solution code is given below:

  • Line 2: The SELECT query uses the COUNT(*) function to count the number of rows in the table. We use AS to set an alias for the column.

  • Line 3: The FROM clause specifies the table, StudentGrades.

  • Line 4: In the WHERE clause, we specified the condition to filter the data. The IS NULL keyword is used specifically to check if the value is NULL.

Recall of relevant concepts

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