MySQL for Test Website - php

Question

I am making a website similar to Moodle. It basically holds tests for students. The confusion comes in when allowing multiple types of questions on the tests and how to create the tables to store the data.
The test_info table will contain the test ID and description.
The test table will contain Test ID and Question ID pairs.
To get the questions for a test this will require a "SELECT * FROM test WHERE testID=$tID" which will take a substantial amount of time to execute when the database gets large.
Originally the questions table contained the question, 4 possibilities and the answer.
How should I store the data for multiple questions and multiple types of questions in a database?
For Example:
Test 51 - "Intro Mathmatics"
Question 1: What is 2+2?
A: 4 B: 12
C: 7 D: 8
Question 2: (0,103) is the range for the equation y=2x/(100x)?
True False
This results in data with 2 different sizes
Questions:
| Question | A | B | C | D | Correct |
| Question | Correct |
If I store these in 1 table it will waste 4 50Char Var-Chars per question and if I store these in 2 separate tables, how will the SELECT know which table to select from?
Questions:
| TestID | TableID | QuestionID |
Questions1:
| Ques | A | B | C | D | Correct |
Questions2:
| Ques | A | B | C | D | Correct |
What a nightmare.

Answer 1

Put the answer in their own table:
answers (answer_id, question_id, description, sequence)
and put the correct answer_id in the question table.

Answer 2

An empty VARCHAR(50) only needs six bits, which means that it will (most likely) take up one byte only on the disk. The VAR in VARCHAR means that the space usage will adapt to the actual data. This means that using one table will "waste" only four bytes per question.
Since you have two types of questions that you handle in two different ways in the code, your two-table approach is viable as well.
The recommended approach is:
Note that four-answer questions and yes-no questions are both special cases of a multiple-choice question. Store these in the database. One possible schema:
question: question_id (PK), test_id (FK), text
answer: answer_id (PK), question_id (FK), text, is_correct
PK = primary key, FK = foreign key

Answer 3

I think you data structure will be like this:
Table1 :Test
id:
TestName:
Table2: Questions:
id:
test_id:
Question:
Answer: //say a,b,c,d
Table3:Answers
id:
question_id:
Anwser Option: //say a,b,c,d
Answer:
Sql For tables with data:
The data will help you in understanding the structure.
CREATE TABLE IF NOT EXISTS `Tests` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`Test` varchar(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;
--
-- Dumping data for table `test2`
--
INSERT INTO `test2` (`id`, `Test`) VALUES
(1, 'Test1');
//////////////////////////////////////
CREATE TABLE IF NOT EXISTS `questions` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`test_id` int(11) NOT NULL,
`Question` varchar(255) NOT NULL,
`Answer` varchar(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;
--
-- Dumping data for table `questions`
--
INSERT INTO `questions` (`id`, `test_id`, `Question`, `Answer`) VALUES
(1, 1, 'question1', 'a'),
(2, 2, 'Question2', 'd');
////////////////////////////////////////////////////
CREATE TABLE IF NOT EXISTS `answers` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`question_id` int(11) NOT NULL,
`answer_option` varchar(10) NOT NULL,
`Answer` varchar(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=8 ;
--
-- Dumping data for table `answers`
--
INSERT INTO `answers` (`id`, `question_id`, `answer_option`, `Answer`) VALUES
(1, 1, 'a', 'True'),
(2, 1, 'b', 'False'),
(3, 2, 'a', 'Asnwer1'),
(4, 2, 'b', 'Answer2'),
(5, 2, 'c', 'Answer3'),
(6, 2, 'd', 'Answer4'),
(7, 2, 'e', 'Answer5');