Question

I am using SQL Server database to store information for my application.

One of the columns in a table has to store the case sensitive data.

How should I set this one specific column in the table to be case sensitive?

EDIT:

1) I use linq to sql for the query
2) I store in the DB info that mast be Case sensative

Answer 1

You can override the collation at the column level and set it to a case sensitive collation.

Following script shows two different ways.

1. Setting a collation during table creation.
2. Setting a collation for an existing column using ALTER statement.

In the collation Latin1_General_CS_AS, CS stands for CASE SENSITIVE

Read here to know more about SQL Server Collation.

Set collation during create table

Create script with collation

CREATE TABLE textvalue
(
     caseinsensitive  VARCHAR(30)
  ,  casesensitive    VARCHAR(30)
        COLLATE Latin1_General_CS_AS
);

Set collation during alter table

Create script with no collation

CREATE TABLE textvalue
(
     caseinsensitive  VARCHAR(30)
  ,  casesensitive    VARCHAR(30)
);

Alter script to set the collation

ALTER TABLE textvalue
    ALTER COLUMN casesensitive VARCHAR(30)
    COLLATE Latin1_General_CS_AS;

Sample that demonstrates with test data

Populate table script

INSERT INTO textvalue (caseinsensitive, casesensitive) VALUES
  ('test', 'Test'),
  ('Test', 'test'),
  ('TeSt', 'TeSt');

Script searching on case sensitive column: SQL Fiddle demo

SELECT  caseinsensitive
    ,   casesensitive  
FROM    textvalue 
WHERE   casesensitive = 'test';

Output:

CASEINSENSITIVE  CASESENSITIVE
---------------  -------------
Test             test

Script searching on case insensitive column: SQL Fiddle demo

SELECT  caseinsensitive
    ,   casesensitive  
FROM    textvalue 
WHERE   caseinsensitive = 'test';

Output:

CASEINSENSITIVE  CASESENSITIVE
---------------  -------------
test             Test
Test             test
TeSt             TeSt