連接運算是 8種關係運算 中的一種。
五種JOIN方式
1.INNER JOIN or JOIN
2.OUTER JOIN
2.1LEFT OUTER JOIN or LEFT JOIN
2.2RIGHT OUTER JOIN or RIGHT JOIN
2.3FULL OUTER JOIN or FULL JOIN
3.NATURAL JOIN
4.CROSS JOIN
5.SELF JOIN
連接運算是 8種關係運算 中的一種。
1.INNER JOIN or JOIN
2.OUTER JOIN
2.1LEFT OUTER JOIN or LEFT JOIN
2.2RIGHT OUTER JOIN or RIGHT JOIN
2.3FULL OUTER JOIN or FULL JOIN
3.NATURAL JOIN
4.CROSS JOIN
5.SELF JOIN