SQL 查询使一列中的所有数据大写？

Permanent:

UPDATE
MyTable
SET
MyColumn = UPPER(MyColumn)

Temporary:

SELECT
UPPER(MyColumn) AS MyColumn
FROM
MyTable

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 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 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 specify how a string should be encoded and read, for example:

• Latin1_General_CI_AS → Case Insensitive
• Latin1_General_CS_AS → Case Sensitive