Computed Column Should Result to String

Computed column should result to string

You're probably defining your computed column as col1+col2. Try CAST(col1 AS NVARCHAR(MAX))+'-'+CAST(col2 AS NVARCHAR(MAX)) instead.

Or if you prefer, you can replace NVARCHAR(MAX) with NVARCHAR(10) or a different length of your choice.

SQL computed column evaluating numbers should return string

You were close. Just a couple of syntax errors. Single quotes and END

ALTER TABLE dbo.test ADD classTest AS CASE 
    WHEN speed > 10 THEN 'fast'
    ELSE 'error' END

Select * from test

speed   classTest
11      fast
5       error

Build a string in a computed SQL column from specific characters from another column

This will produce YYMM, like 2102, 2103, etc.:

SELECT CONVERT(char(4), GETDATE(), 12);

So we can add that to the existing computed column formula. Since BillingDateTo is a computed column, you can't nest those; you have to repeat the computed column expression for BillingDateFrom or, instead of using multiple computed columns, just expose these additional calculations in a view.

ALTER TABLE dbo.whatever ADD BillingDealerPeriodID 
  AS (CONVERT(char(4), DATEADD(DAY, 7, BillingDateFrom), 12));

• Example db<>fiddle

If you really want MMYY instead of YYMM, you can do:

SELECT STUFF(CONVERT(char(10), GETDATE(), 110),3,6,'');

So as a computed column:

ALTER TABLE dbo.whatever ADD BillingDealerPeriodID 
  AS STUFF(CONVERT(char(10), DATEADD(DAY, 7, BillingDateFrom), 110),3,6,'');

• Example db<>fiddle

The documentation doesn't do a great job of explicitly stating that computed columns can't be nested, other than the following:

The expression can be a noncomputed column name

But the error message that results if you try is pretty explicit.

As an aside, I strongly recommend staying away from variations that use FORMAT() - while it's convenient, intuitive, and better matches capabilities in other more sophisticated languages, it is unacceptably slow (and also doesn't work in off-shoots like Azure SQL Edge).

Adding a calculated field to convert string value to date in T-SQL

The error on expiry_date seems quite clear -- that is not the name of a column in the table. But you can simplify the logic:

ALTER TABLE TEM.AssignmentRates ADD Date_Expired AS
    (TRY_CONVERT(date, Expiry_Date));

Actually, the nested SELECT may have caused an issue. That would not normally be used for a computed column.

Create computed column with string in formula

This actually sorted it out for me at the end.....

NavigateUrl='<%# String.Format("{0}.aspx?ID={1}", DataBinder.Eval(Container.DataItem, "Category"), DataBinder.Eval(Container.DataItem, "Post_ID")) %>'

SQL Server: STRING_SPLIT() result in a computed column

At this time your answer is not possible.

The output rows might be in any order. The order is not guaranteed to
match the order of the substrings in the input string.

STRING_SPLIT reference

There is no way to guarantee which item was the third item in the list using string_split and the order may change without warning.

If you're willing to build your own, I'd recommend reading up on the work done by

Brent Ozar and Jeff Moden.

Is Custom Text supported in Computed columns?

Yes, as long as you stick with correct T-SQl expresions:

(cast([Duration] as varchar(...)) + 'MyCustomText')

SQL computed column based on a special character on another column

You would use a case expression and like:

select t.*,
       (case when a like '%$%' then 'YES' else 'NO' end) as c
from t;

The following is just commentary.

This is very basic syntax for SQL. I would recommend that you spend some time to learn the basics. Learning-as-you-go is an okay approach -- assuming you have some fundamentals to build on. Otherwise, you are likely to spend a lot of time to learn a few things, and you may not learn the best way to do things.

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