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How do I get SUM function in MySQL to return '0' if no values are found?

Say I have a simple function in MySQL:

$query="SELECT SUM(Column 1) from Table WHERE Column 2='Test'";

If no entries in Column 2 contain the text 'Test' then this function returns NULL, when I would like it to return 0. I'm aware that a similar question has been asked a few times here, but I haven't been able to adapt the answers to my purposes, so I'd be grateful for some help to get this sorted.

Thanks,

Nick

Linq query with nullable sum

from i in Db.Items
select new VotedItem
{
    ItemId = i.ItemId,
    Points = (from v in Db.Votes
              where b.ItemId == v.ItemId
              select v.Points).Sum()
}

I got this query, however it fails if no votes are found with exception:

The null value cannot be assigned to a member with type System.Int32 which is a non-nullable value type.

I assume its because sum returns an int and not a nullable int, giving sum a int? as input only give the same error, probably cause sum only workes on ints.

Any good workaround for this?

Get sum of two columns in one LINQ query

let's say that I have a table called Items (ID int, Done int, Total int)

I can do it by two queries:

int total = m.Items.Sum(p=>p.Total)
int done = m.Items.Sum(p=>p.Done)

But I'd like to do it in one query, something like this:

var x = from p in m.Items select new { Sum(p.Total), Sum(p.Done)};

Surely there is a way to call aggregate functions from LINQ syntax...?

Add SUM of values of two LISTS into new LIST

I have the following two lists:

first = [1,2,3,4,5]
second = [6,7,8,9,10]

Now I want to add items of both lists into a new list.

output should be

three = [7,9,11,13,15]

How do you find the sum of all the numbers in an array in java?

I'm having a problem finding the sum of all of the integers in an array in java. Cannot find any useful method in the Math class for this.

How to sum all values of a column of in a data.frame?

I have a data frame with several columns; some numeric and some character. How to compute the sum of a specific column? I’ve googled for this and I see numerous functions (sum, cumsum, rowsum, rowSums, colSums, aggregate, apply) but I can’t make sense of it all.

For example suppose I have a data frame people with the following columns

Name Height Weight
Mary 65     110
John 70     200
Jane 64     115
…

How do I get the sum of all the weights?

Sum range of int's in List

I reckon this will be quite trivial but I can't work out how to do it. I have a List<int> and I want to sum a range of the numbers.

Say my list is:

var list = new List<int>()
{
    1, 2, 3, 4
};

How would I get the sum of the first 3 objects? The result being 6. I tried using Enumerable.Range but couldn't get it to work, not sure if that's the best way of going about it.

Without doing:

int sum = list[0] + list[1] + list[2];

Getting N random numbers that the sum is M

I want to get N random numbers that the sum of them is a value.

For example, let's suppose I want 5 random numbers that their sum is 1

Then, a valid possibility is:

0.2 0.2 0.2 0.2 0.2

Other possibility is:

0.8 0.1 0.03 0.03 0.04

And so on. I need this for the creation of the matrix of belongings of the Fuzzy C-means.

How to calculate sum of a DataTable's Column in LINQ (to Dataset)?

I'm just started to read up on LINQ and I want to start incorporating it into my code. I know how to compute the sum of a DataTable's column by either "Foreach"-ing through the rows or by doing a compute.sum on the specific column. How do I do the equivalent with LINQ to DataSet?

How to sum array of numbers in Ruby?

I have an array of integers.

For example:

array = [123,321,12389]

Is there any nice way to get the sum of them?

I know, that

sum = 0
array.each { |a| sum+=a }

would work.

C# List of objects, how do I get the sum of a property

I have a list of objects. One property of the individual object entry is amount. How do I get the sum of amount?

If my list was of type double I may be able to do something like this:

double total = myList.Sum();

However I want to something similar to this, yet this syntax is incorrect.

double total = myList.amount.Sum();

How should I go about accomplishing this? I would love to use the Sum function if possible instead of looping through and calculating the value.

Using GroupBy, Count and Sum in LINQ Lambda Expressions

I have a collection of boxes with the properties weight, volume and owner.

I want to use LINQ to get a summarized list (by owner) of the box information

e.g.

**Owner, Boxes, Total Weight, Total Volume**  
Jim,     5,     1430.00,      3.65  
George,  2,     37.50,        1.22

Can someone show me how to do this with Lambda expressions?

Sum of all values in a Python dict

I'm new to Python. Let's say I have a dictionary in which the keys map to integers like:

d = {'key1':1,'key2':14,'key3':47}

Is there a syntactically minimalistic way to return the sum of the values in d--i.e. 62 in this case.

Thanks

SQL Update to the SUM of its joined values

I'm trying to update a field in the database to the sum of its joined values:

UPDATE P
SET extrasPrice = SUM(E.price)
FROM dbo.BookingPitchExtras AS E
INNER JOIN dbo.BookingPitches AS P ON E.pitchID = P.ID
    AND P.bookingID = 1
WHERE E.[required] = 1

When I run this I get the following error:

"An aggregate may not appear in the set list of an UPDATE statement."

Any ideas?

How to sum properties of the objects within an array in Ruby

I understand that in order to sum array elements in Ruby one can use the inject method, i.e.

array = [1,2,3,4,5];
puts array.inject(0, &:+) 

But how do I sum the properties of objects within an object array e.g.?

There's an array of objects and each object has a property "cash" for example. So I want to sum their cash balances into one total. Something like...

array.cash.inject(0, &:+) # (but this doesn't work)

I realise I could probably make a new array composed only of the property cash and sum this, but I'm looking for a cleaner method if possible!