SQL Query to look up one table against another - sql

Question

I have two Excel tables- the first one is the data table and the second one is a look up table. Here is how they are structured-
Data Table
+----------+-------------+----------+----------+
| Category | Subcategory | Division | Business |
+----------+-------------+----------+----------+
| A | Red | Home | Q |
| B | Blue | Office | R |
| C | Green | City | S |
| D | Yellow | State | T |
| D | Red | State | T |
| D | Green | Office | Q |
+----------+-------------+----------+----------+
Lookup Table Lookup Table
+----------+-------------+----------+----------+--------------+
| Category | Subcategory | Division | Business | LookUp Value |
+----------+-------------+----------+----------+--------------+
| 0 | 0 | 0 | Q | ABC |
| B | 0 | Office | 0 | DEF |
| C | Green | 0 | 0 | MNO |
| D | 0 | State | T | RST |
+----------+-------------+----------+----------+--------------+
So I want to add the lookup value column to the data table based on the criteria given in the lookup table. Eg, for the first row in the lookup table, I dont want to lookup on Category, Subcategory, or Division. but if the Business is Q, then I want to populate the lookup value as ABC. Similarly, for the second row I dont want to consider the Subcategory. and Business. but if the Category. is "B" and Division is "Office", I want it to populate DEF. So the result should look like this-
[Final Resulting Data Table]
+----------+-------------+----------+----------+--------------+
| Category | Subcategory | Division | Business | LookUp Value |
+----------+-------------+----------+----------+--------------+
| A | Red | Home | Q | ABC |
| B | Blue | Office | R | DEF |
| C | Green | City | S | MNO |
| D | Yellow | State | T | RST |
| D | Red | State | T | RST |
| D | Green | Office | Q | ABC |
+----------+-------------+----------+----------+--------------+
I am very new to SQL and the actual data set is very complex wih multiple lookup values based on different criteria. IF you think any other scripting language would work better, I am open to that too. My data is in Excel currently

Answer 1

If the data is so complex, you should first consider if you want to put it in a (relational) database (like MS Access, MySQL, etc.) instead of in a spreadsheet (like MS Excel).
Both kind of programs are used for structured data handling, but databases focus primarily on efficient data storage and data integrity (including guarding type safety, required fields, unique fields, required references between various datasets/tables, etc.) and spreadsheets focus primarily on data analysis and calculations.
Relational databases support Structured Query Language (SQL) to let clients query their data. Spreadsheets normally do not use or support SQL (as far as I know).
It is possible to let MS Excel import or reference data in an external data source (like a relational database) to perform analysis and calculations on it.
The other way around is (sometimes) possible too: to link to spreadsheet worksheets as external tables inside a relational database system to - within certain limits - allow that data to be queried using SQL. But using a database to store the data and a spreadsheet (as a database client) to perform analysis on the data in the database would be a more logical design in my opinion.
However, creating such an integrated solution using multiple MS Office applications and/or external databases can be a complex challenge, especially when you are just starting to learn about them.
To be honest, I am not experienced with designing MS Office based solutions, so I cannot guide you around any pitfalls. I do hope, that this answer helps you a little with finding the right way to go here...