sql - TSQL 比较两个集合

Question

当给出两组时

s1 ={a,b,c,d} s2={b,c,d,a}

(即)

TableA

Item
a
b
c
d

TableB

Item
b
c
d
a

如何编写Sql查询来显示“tableA和tableB中的元素相等”。 [不使用SP或UDF]

输出

Elements in TableA and TableB contains identical sets

Answer 1

用途:

SELECT CASE 
         WHEN   COUNT(*) = (SELECT COUNT(*) FROM a) 
            AND COUNT(*) = (SELECT COUNT(*) FROM b) THEN 'Elements in TableA and TableB contains identical sets'
         ELSE 'TableA and TableB do NOT contain identical sets'
       END
  FROM (SELECT a.col
          FROM a
        INTERSECT
        SELECT b.col
          FROM b) x 

测试:

WITH a AS (
  SELECT 'a' AS col
  UNION ALL
  SELECT 'b'
  UNION ALL
  SELECT 'c'
  UNION ALL
  SELECT 'd'),
     b AS (
  SELECT 'b' AS col
  UNION ALL
  SELECT 'c'
  UNION ALL
  SELECT 'd'
  UNION ALL
  SELECT 'a')
SELECT CASE 
         WHEN   COUNT(*) = (SELECT COUNT(*) FROM a) 
            AND COUNT(*) = (SELECT COUNT(*) FROM b) THEN 'yes'
         ELSE 'no'
       END
  FROM (SELECT a.col
          FROM a
        INTERSECT
        SELECT b.col
          FROM b) x