Sql – Average, Count, etc of entire column of table in SQL Query or as Function in VBA to Display result in Form

ms-accesssqlvba

I need to calculate Count, Average and a couple other things of a column as a result of a Query and then put the result in a text box in a form.

I was thinking about either implementing it in the Query and putting the results in a column or something like that, OR use a VBA function to calculate it; however I don't know how to calculate this for an entire column in VBA.

Any suggestions/examples?

Best Solution

Actually I found that this is very easy in VBA. I didn't want to add another field to my Query so I did this:

Forms!MyForm!AvgTextBox = Avg([mytable.values2Baveraged])
Forms!MyForm!CountTextBox = Count([mytable.values2Bcounted])

This calculates the function on the entire column. This worked perfectly just in case anyone cared.

Syntax:

ALTER TABLE {TABLENAME} 
ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL} 
CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE}
WITH VALUES

Example:

ALTER TABLE SomeTable
        ADD SomeCol Bit NULL --Or NOT NULL.
 CONSTRAINT D_SomeTable_SomeCol --When Omitted a Default-Constraint Name is autogenerated.
    DEFAULT (0)--Optional Default-Constraint.
WITH VALUES --Add if Column is Nullable and you want the Default Value for Existing Records.

Notes:

Optional Constraint Name:
If you leave out CONSTRAINT D_SomeTable_SomeCol then SQL Server will autogenerate
a Default-Contraint with a funny Name like: DF__SomeTa__SomeC__4FB7FEF6

Optional With-Values Statement:
The WITH VALUES is only needed when your Column is Nullable
and you want the Default Value used for Existing Records.
If your Column is NOT NULL, then it will automatically use the Default Value
for all Existing Records, whether you specify WITH VALUES or not.

How Inserts work with a Default-Constraint:
If you insert a Record into SomeTable and do not Specify SomeCol's value, then it will Default to 0.
If you insert a Record and Specify SomeCol's value as NULL (and your column allows nulls),
then the Default-Constraint will not be used and NULL will be inserted as the Value.

Notes were based on everyone's great feedback below.
Special Thanks to:
@Yatrix, @WalterStabosz, @YahooSerious, and @StackMan for their Comments.

Sql – How to get column names from a table in SQL Server

You can obtain this information and much, much more by querying the Information Schema views.

This sample query:

SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = N'Customers'

Can be made over all these DB objects:

Best Solution

Related Solutions

Sql – Add a column with a default value to an existing table in SQL Server

Syntax:

Example:

Notes:

Sql – How to get column names from a table in SQL Server

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