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mysqlsqlinner-join

How to understand the SQL SYNTAN which join a table to itself without using INNER JOIN?

There is a TABLE name is team, total 1 column 'name' with 4 records ('a', 'b', 'c', 'd') representing four football teams.

Requires: Using one SQL syntax to show all the possible combinations of tow team.

I just learned about self_join so i used this:

SELECT a.name, b.name
FROM team AS a
INNER JOIN team AS b
WHERE a.name < b.name;

The question is: I saw the SQL SYNTAX which works out pretty good, but i can't figure out how it works. Anyone could help? thx.

This SQL SYNTAX is below:

SELECT a.name, b.name
from team a, team b 
where a.name < b.name;
Solution

  • These queries are just different ways to write the same thing. The first is ANSI-89 join syntax, the second ANSI-92 join syntax. The newer syntax is preferred because it keeps join conditions closer to the joined table, especially for multiple joins.