Comments - column name work as a case insenstive

You haven't given any details of your table or the failing query, but it sounds like you're using a case-insensitive collation. See Character Set and Collation Overview.

For example:

CREATE OR REPLACE TABLE t1 (
  c VARCHAR(1) COLLATE latin1_swedish_ci PRIMARY KEY 
);
INSERT INTO t1 VALUES ('A'),('a');
ERROR 1062 (23000): Duplicate entry 'a' for key 'PRIMARY'

Everything is fine if you use a case-sensitive collation:

CREATE OR REPLACE TABLE t2 (
  c VARCHAR(1) COLLATE latin1_bin PRIMARY KEY 
);
INSERT INTO t2 VALUES ('A'),('a');

I guess they are facing the issue while inserting the value 'a' after inserting 'A'. As MariaDB is not able to identify whether the 'a' or 'A' are different. I think there might be some configuration that needs to be set so that the MariaDB works in Case-Sensitive mode.

Have you looked at the collation?

Yup, so if we change the default collation from "latin1_swedish_ci " to "latin1_bin" then the comparison will be case-sensitive. Thanks to you Let me modify this.

how can be set as a globally?.it will work for one table.

I think you'd have to change collation on all tables. And you can set collation for the database itself too, which affects newly created tables?