T sql sum null

Suppose that we insert some more records in the numbers table using the following query statement. The output will be different from that of the first query without a distinct function because internally, the calculation of total value by SUM function will only consider the repeated column values, such as and , only once.

We can use the expressions in the SUM function to consider the value evaluated by calculating each of the formula or expression values containing column value to calculate the total value. Let us consider one example; we will calculate the total of all the columns after they are multiplied by 10 and added by 1.

When we have complex tables and relations between multiple tables, we have to query those tables using joins to retrieve data, usually for reporting purposes that consist of summarized data. Even in some scenarios, the data from a single table need to be manipulated to get summarized data. Suppose that we have one table named workers consisting of the following records in it that are retrieved by executing a simple select query on that table.

Now, the situation is such that we have to calculate the total salary of the workers per team. The output should consist of the team id and the total salary of that team. For this, we will have to use the group by statement and group the records based on team id and calculate the total salary by using the SUM function.

The execution of the above query statement will give the following output along with team ids and their respective total salaries. I have updated my answer to better explain what I really mean here. Maybe the answer is correct for ayilmaz, but if we don't check for NULL, it maybe a point of concern in many cases.

However, your answer is correct in this situation. This is a bad habit to form. Community Bot 1 1 1 silver badge. SandeepKumar - Please refer this post: stackoverflow. Or you receive null — vohrahul. This answer should get more up-votes! Thanks Chris. That's why i clearly mentioned in my comments as well. Not using null check might be a concern if you are using this value in some other expression or calculation. Anyway, thanks for the appreciation. Show 6 more comments.

Ragesh Ragesh 3 3 silver badges 8 8 bronze badges. Unless all values are null, in which case it returns null, as pointed out by vohrahul. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. If not specified, the function treats all rows of the query result set as a single group.

Returns the summation of all expression values in the most precise expression data type. For more information, see Deterministic and Nondeterministic Functions. The following examples show using the SUM function to return summary data in the AdventureWorks database. SalesPerson table in the AdventureWorks database. This means that the SUM function is computed for each territory based on the sales year. Notice that for TerritoryID 1, there are two rows for sales year representing the two sales people with sales that year.

The cumulative sales total for these two rows is computed and then the third row representing sales for the year is included in the computation.