Remove unwanted text from column values - sql

Question

I dont know how to do this. On my table I have descriptions mixed with description code. I need to remove the code description, just want the description. The description is just the first part without the acronym (capital letters at the end). I use SQL Server 2012
Example:
ColumnDescription
Chemistry Q
education E
psychology P
Sociology SOC
Documentation DOC
communication COM
Political Science CP
Pharmacy and Toxicology FT
Engineering Education (General) ING-G

Answer 1

If you are looking to simply strip the code that is at the end of each string, a way to do this is to identify the last space character in the string and then use SUBSTRING to extract everything before that character:
SELECT SUBSTRING(ColumnDescription, 0, LEN(ColumnDescription) - CHARINDEX(' ', REVERSE(ColumnDescription)) + 1) AS ColumnDescription
FROM Table
Note that I do not know what your table is called, so I called it Table.
This effectively reverses the column text (using REVERSE), finds the first occurrence of a space character (using CHARINDEX) and then subtracts this from the length of the text (using LEN).
Then a simple SUBSTRING is used to extract the left-most portion of the text, resulting in the output of:
ColumnDescription
-----------------
Chemistry
education
psychology
Sociology
Documentation
communication
Political Science
Pharmacy and Toxicology
Engineering Education (General)

Answer 2

Based on your sample data I would guess that your problem could be simplified to:
Split the string at the last space character in the string
In which case:
DECLARE #your_table table (
ColumnDescription varchar(100)
);
INSERT INTO #your_table (ColumnDescription)
VALUES ('Chemistry Q')
, ('education E')
, ('psychology P')
, ('Sociology SOC')
, ('Documentation DOC')
, ('communication COM')
, ('Political Science CP')
, ('Pharmacy and Toxicology FT')
, ('Engineering Education (General) ING-G');
SELECT *
, SubString(ColumnDescription, number_of_characters - last_space + 2, 100) As last_part
, SubString(ColumnDescription, 0, number_of_characters - last_space + 2) As first_part
FROM (
SELECT ColumnDescription
, Len(ColumnDescription) As number_of_characters
, Reverse(ColumnDescription) As reversed
, CharIndex(' ', Reverse(ColumnDescription)) As last_space
FROM #your_table
) As x;