PART III:Thinking in Sets
CHAPTER7 Thinking in Sets
The three mostcommon set operations are as follows.
Intersection
Difference
Union
?
在SQL中相应的关键词分别是
IntersectionExcept
Union
?
OUTER JOIN
UNION JOIN
?
不过其区别是前者集合操作涉及表中所有列的值,而JOINs则只涉及到表中指定的列值.
SQL查询初学者指南读书笔记(五)集合操作与多表查询介绍
PART III:Thinking in Sets
CHAPTER7 Thinking in Sets
The three mostcommon set operations are as follows.
Intersection
Difference
Union
Except
Union
OUTER JOIN
UNION JOIN