SQL Exercise: Count the number available rooms

SQL hospital Database: Exercise-6 with Solution

6. From the following table, write a SQL query to count the number available rooms. Return count as "Number of available rooms".

Sample table: room

Sample Solution:

-- This SQL query counts the number of available rooms from the room table where the 'unavailable' column is set to 'false'.

SELECT count(*) "Number of available rooms" -- Counts the number of rows and aliases the result column as "Number of available rooms"
FROM room -- Specifies the table from which to retrieve data, in this case, the room table
WHERE unavailable='false'; -- Filters the rows to include only those where the 'unavailable' column is set to 'false'

Sample Output:

 Number of available rooms
---------------------------
                        29
(1 row)

Explanation:

The said query here in SQL that counts the number of available rooms in the room table.

The query selects all columns (*) from the room table where the unavailable column is set to 'false'.

The resulting output is a single row with a single column, showing the number of available rooms in the room table. The column will be labeled "Number of available rooms".

Pictorial presentation:

Practice Online

E R Diagram of Hospital Database:

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