This SQL query performs the following operations: 1. **FROM Clause**: ...

This SQL query performs the following operations:

1. FROM Clause:

   • It is selecting data from the table Battery_Traffic.

2. WHERE Clause:

   • It filters the data such that only rows where the column "TimeStamp" falls within the range of 4 hours ago to 1 hour ago (relative to the current time) are considered.
   • It further filters the data to exclude rows where the value of "NDBC" is either 1 or 99999.

   So, only rows meeting both criteria are used for the calculation.

3. SELECT Clause:

   • The query calculates a specific percentage value derived from the "NDBC" column:
     • (COUNT("NDBC")::float):
       • Counts the total number of rows that satisfy the conditions from the WHERE clause and casts the count to a float for division.
     • (COUNT(DISTINCT "NDBC") * 18):
       • Counts the distinct number of values in the "NDBC" column and multiplies it by 18.
     • The two values above are divided by one another and multiplied by 100 to compute a percentage.

4. Purpose:

   • The result of the query gives a percentage that represents the ratio of the count of "NDBC" rows to the product of the distinct count of "NDBC" values (multiplied by 18), restricted to the filtered data within the specified time frame.

In summary, this query calculates a percentage metric based on the number of occurrences of "NDBC" and the number of distinct "NDBC" values in the filtered data from the last 3 hours (excluding 1 hour ago to the current time).