Calculating length of ntext data type with T-SQL

Ferhat Karataş — Wed, 15 Dec 2021 20:27:47 +0000

We use the LEN() function when calculating the length of a String field. But when you use this function in fields with ntext datatype, you will get the following error.

Argument data type ntext is invalid for argument 1 of len function.

In this case, another function you can use as an alternative is DATALENGTH()

But DATALENGTH returns us the number of bytes instead of the number of characters. Each character in the String is 2 bytes.

For example, if the result is 28, it means it's 14 characters.

select top 1 datalength(NameSurname), NameSurname from Customer order by CreateDate

How to prevent duplicate count value for inner join

Ferhat Karataş — Thu, 28 Oct 2021 14:19:54 +0000

When you join two tables and you want to count only the first table, you can use the distinct command.

select a.OrderID, count(distinct a.Id) as Total from tblOrder a 
inner join tblOrderDetail b on a.OrderID = b.OrderID

DEV Community: Ferhat Karataş

Calculating length of ntext data type with T-SQL

How to prevent duplicate count value for inner join