naming a column in a table with the same name as another table in the same db

[Nick Lombardi]

Hello

In creating an online testing system, I need to name a column in a student table to hold the score for exams which are in separate tables, and I thought the most straightforward way was to give them the same names. As this was an afterthought, I renamed the column in the student table using ALTER TABLE command.
Now, when I try to select from the exam table, I get an error in query saying the old column name in the student table is an unknown field.

Error in query:SELECT correct_answer FROM sampletest WHERE id = '2"'.Unknown column 'exam1_grade' in 'field list'

I'm baffled as the test table has nothing to do with the student table.
In the student table I renamed the column 'exam1_grade', to 'sampletest', the same name as the table that holds the questions and answers.