SQL: Visual QuickStart Guide

Creating an Inner Join with INNER JOIN

An inner join:

• Uses a comparison operator (=, <>, <, <=, >, or >=) to match rows from two tables based on the values in common columns from each table. You can retrieve all rows in which the author identifier (the column au_id) is the same in both the tables authors and title_authors, for example.

• Returns a result that contains only joined rows that satisfy the join condition(s).

• Is the most common type of join; I’ll give many examples.

To create an inner join:

• Type:

  SELECT columns
    FROM table1
    INNER JOIN table2
      ON join_conditions
  							

  columns is one or more comma-separated expressions or column names from table1 or table2. table1 and table2 are the names of the joined tables. If the tables have some column ...