内连接又称等值连接，使用 INNER JOIN 关键字 ~~~ SELECT A.value, B.value FROM tablea AS A INNER JOIN tableb AS B ON A.key = B.key; ~~~ 可以不明确使用 INNER JOIN，而使用普通查询并在 WHERE 中将两个表中要连接的列用等值方法连接起来。 ~~~ SELECT A.value, B.value FROM tablea AS A, tableb AS B WHERE A.key = B.key; ~~~