When using the count() function in SQLite, you might find yourself in the situation where you only want to count distinct values. That is, you don’t want duplicate values to be counted multiple times.
Category: Relational
List all Temporary Tables in SQLite
As with most things in SQLite, there’s more than one way to get a list of temporary tables in a database.
Here I present two ways to return temporary tables in SQLite.
Continue reading2 Ways to List the Tables in an SQLite Database
Here are two ways to return a list of tables in all attached databases in SQLite.
The first method returns all tables and views for all attached databases.
The second method gives you the option of returning both tables and views, or just tables, but only for the primary database.
Update Dec 2021: Since writing this article, SQLite has introduced another option, which I’ve listed as a bonus third option at the end of this article.
Continue readingSQLite Sum() vs Total(): What’s the Difference?
SQLite has a function called sum() and another function called total(). Both functions do pretty much the same thing – they return the sum of all non-NULL values in a group.
But there is a subtle difference between these two functions.
The difference is in the way they handle NULL inputs.
Continue readingHow SQLite Total() Works
In SQLite, the total() function returns the sum of all non-NULL values in a group.
If there are no non-NULL values, then it returns 0.0.
This function is similar to the sum() function, except in the way it handles NULL inputs. When there are no non-NULL values, then sum() returns NULL (instead of 0.0 like the total() function returns).
How SQLite Sum() Works
The SQLite sum() function returns the sum of all non-NULL values in a group.
If there are no non-NULL values, then it returns NULL.
This function basically enables you to add up all the values in a result set or a table.
Continue readingHow SQLite Min() Works
The SQLite min() function returns the minimum non-NULL value from all values in a group.
The minimum value is the value that would appear first in a query that uses an ORDER BY clause on the same column.
How SQLite Max() Works
The SQLite max() function returns the maximum value from all values in a group.
The maximum value is the value that would appear last in a query that uses an ORDER BY clause on the same column.
How SQLite Avg() Works
The SQLite avg() function returns the average value of all non-NULL values within a group.
It accepts one argument, which is the value or group of values.
Continue readingCombine SQLite Count() with GROUP BY to Add a “Count” Column to your Result Set
If you need to add a “count” column to the result set of a database query when using SQLite, you can use the count() function to provide the count, and the GROUP BY clause to specify the column for which to group the results.