Choosing Between Redis and a Traditional Relational Database.Measuring Query Execution Time in Relational Databases.In any event, either function could be employed to group results by month. Notice how applying the MONTHNAME function on the rental_month output field displays the full month name rather than the month number as the MONTH() function does. Click OK to close the Query Builder and return to the Query Editor.The Query Builder should now look like this: Click on the label and use the editor to enter "MONTH(rental_date)".Click on the label and enter an Alias of "rental_count".Click the label and choose COUNT from the list.This time, select rental_id from the field list. Click on the label and enter a value of "rental_month".In the editor, enter "MONTHNAME(rental_date)". Join the two tables on the film.film_id and rental.inventory_id fields by dragging the former over to the latter.Drag the film and rental tables into the editor.Let's design a query to show a count of rented films by month. It is also possible to group records by one or more columns using the GROUP BY clause. The above results pertain to the entire table. Here is a query that uses aggregate functions to display the number of films, average film length, total film length, as well as the minimum and maximum rental rates: Selecting the desired function from the list will insert it into the query: MAX(): Returns the maximum of the non-NULL values in the specified field.Īs touched upon in Part 2, clicking the modifier the the left of an output field in the Navicat Query Builder opens a list of SUM, MAX, MIX, AVG, and COUNT aggregate functions.MIN(): Returns the minimum of the non-NULL values in the specified field. AVG(): Returns the average of the non-NULL values in the specified field.SUM(): Returns the sum of the non-NULL values in the specified field.COUNT(): Returns the number of rows containing non-NULL values in the specified field.Aggregate functions include COUNT, MAX, MIN, SUM, and AVG: In SQL, output fields may be passed to aggregate functions to produce statistics for the column data. Please refer to the Generating Reports on MySQL Data tutorial for instructions on downloading and installing the Sakila database. It contains a number of tables themed around the film industry that cover everything from actors and film studios to video rental stores. About the Sakila Sample DatabaseĪs with previous installments, the queries that we'll be building here today will run against the Sakila sample database. This installment on the Navicat Query Builder describes how to include native SQL aggregate functions in your queries to display column statistics. In addition to fetching individual values, the SELECT statement is also able to aggregate data elements based on one or more columns.
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