Question

Using phpMyAdmin 5.1.44 to experiment with DML commands.

I’ve been following tutorials on-line.

SELECT book.b_isbn, publisher.p_name FROM 'book', 'publisher' WHERE book.b_title='DSA'

Table 1

book

b_id(PK)    b_isbn     b_title   p_id(FK)
-----------------------------------------
1           12345      DSA       1
2           23456      SD        1
3           34567      CSP       2

Table 2

publisher

p_id(PK)    p_name
--------------------
1           Fred
2           John

Expected Results

b_isbn      p_name
---------------------
12345       Fred

Actual Results

b_isbn      p_name
----------------------
12345       Fred
34567       John

Any ideas?

Answer 1

You need to tell MySQL how to join the tables together (without which it just matches every book to every publisher) – use any one of:

1. add AND publisher.p_id = book.p_id to your WHERE clause;

2. tell MySQL to join ON that condition / USING that column;

   ... FROM book JOIN publisher ON publisher.p_id = book.p_id WHERE ...
   

   or

   ... FROM book JOIN publisher USING (p_id) WHERE ...
   

3. use a NATURAL JOIN to have MySQL guess that’s what you want based on the column names.

   ... FROM book NATURAL JOIN publisher WHERE ...