If you want to *only update on rows that are not currently uppercase* (instead of all rows), you'd need to identify the difference using [`COLLATE`][2] like this:

 UPDATE MyTable
 SET MyColumn = UPPER(MyColumn)
 WHERE MyColumn != UPPER(MyColumn) COLLATE Latin1_General_CS_AS 

----

### A Bit About Collation

Cases sensitivity is based on your collation settings, and is typically case insensitive by default.

Collation can be set at the [Server, Database, Column, or Query][1] Level:

 -- Server
 SELECT SERVERPROPERTY('COLLATION')
 -- Database
 SELECT name, collation_name FROM sys.databases
 -- Column 
 SELECT COLUMN_NAME, COLLATION_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE CHARACTER_SET_NAME IS NOT NULL

[Collation Names][3] specify how a string should be encoded and read, for example:

* <code>Latin1_General_CI_AS</code> → Case Insensitive
* <code>Latin1_General_CS_AS</code> → Case Sensitive


[1]: https://www.webucator.com/how-to/how-check-case-sensitivity-sql-server.cfm
[2]: https://learn.microsoft.com/en-us/sql/t-sql/statements/collations
[3]: https://learn.microsoft.com/en-us/sql/t-sql/statements/sql-server-collation-name-transact-sql

I need a SQL query to make all data in a column UPPER CASE?

Any ideas?