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.
Tag: functions
SQLite 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.
How SQLite Count() Works
The SQLite count() function can be used to return the number of rows in a result set.
It can also be used to return the number of times a given column is not NULL in the result set.
It can be used in two ways. If you pass in the asterisk (*) wildcard character, it will return the total number of rows in the group. If you provide the name of a column, it will return the number of times that column is not NULL.
Valid Format String Substitutions for the SQLite Strftime() Function
The table below contains the valid format string substitutions that you can use with the strftime() function in SQLite.