Write a query to display the meter_id and total_units of electricity_reading whose '13th' hour reading is lesser than the '14th' hour reading, Display the records in descending order based on their total_units.

Assuming you are using SQL, here is a step-by-step guide on how to write the query:

1. Identify the table: From the question, it seems like the table you are working with is electricity_reading.

2. Identify the columns: The columns you are interested in are meter_id, total_units, 13th_hour_reading, and 14th_hour_reading.

3. Write the SELECT statement: Start your query with SELECT meter_id, total_units FROM electricity_reading.

4. Write the WHERE clause: You want to display records where the '13th' hour reading is lesser than the '14th' hour reading. So, add WHERE 13th_hour_reading < 14th_hour_reading.

5. Write the ORDER BY clause: You want to display the records in descending order based on their total_units. So, add ORDER BY total_units DESC.

Putting it all together, your query should look like this:

SELECT meter_id, total_units 
FROM electricity_reading 
WHERE 13th_hour_reading < 14th_hour_reading 
ORDER BY total_units DESC;

Please replace 13th_hour_reading and 14th_hour_reading with the actual column names in your table.

Assuming you are using SQL and your table name is 'electricity_reading', the query would look something like this:

SELECT meter_id, total_units
FROM electricity_reading
WHERE hour_13 < hour_14
ORDER BY total_units DESC;

This query works as follows:

1. SELECT meter_id, total_units: This line is selecting the columns 'meter_id' and 'total_units' to be displayed in the output.

2. FROM electricity_reading: This line is specifying the table from which to select these columns.

3. WHERE hour_13 < hour_14: This line is the condition for the rows to be selected. It's only selecting the rows where the reading of the 13th hour is less than the reading of the 14th hour.

4. ORDER BY total_units DESC: This line is ordering the selected rows based on the 'total_units' column in descending order.