Question

嘿所有我想要找出一种从以下SQL查询发送 2个结果表的方法：

SELECT
  CASE WHEN EXISTS 
  (
      SELECT name FROM usersTbl WHERE name = 'Bob Barker' 
  ) 
  THEN 'TRUE'
  ELSE 'FALSE'
END AS result1

|result1  |
|---------|
| TRUE    |

现在上面的查询工作得很好。但是，我需要执行另一个选择语句，如果它的＆＃39; TRUE＆＃39; 是这样的：

SELECT
  CASE WHEN EXISTS 
  (
      SELECT * FROM usersTbl WHERE name = 'Bob Barker' 
  ) 
  THEN 'TRUE'
      (SELECT name FROM usersTbl WHERE name = 'Bob Barker'
                              AND active = 1) AS result2
  ELSE 'FALSE'
END AS result1

|result1  |
|---------|
| TRUE    |

|result2       |
|--------------|
| Bob Barker   |

因此，不再只是 result1 返回，这将允许返回 result1和result2 。

我该如何格式化查询呢？

Answer 1

您查询看起来有点错误......应该是

{{1}}

Answer 2

有点奇怪，但如果你想要2个结果集，你可以使用IF EXISTS()：

IF EXISTS (SELECT * FROM usersTbl WHERE name = 'Bob Barker')
BEGIN
    SELECT 'TRUE' as Result1;
    SELECT CASE WHEN EXISTS (SELECT * 
                             FROM usersTbl 
                             WHERE name = 'Bob Barker'
                             AND active = 1)
                THEN (SELECT name
                      FROM usersTbl 
                      WHERE name = 'Bob Barker'
                      AND active = 1)
                ELSE 'FALSE'
                END as Result2;
END

如果您想在第一个结果不存在时返回FALSE，则必须添加另一个IF：

IF NOT EXISTS (SELECT * FROM usersTbl WHERE name = 'Bob Barker')
BEGIN
   SELECT 'FALSE';
END

修改：最终FALSE的完整查询：

IF EXISTS (SELECT * FROM usersTbl WHERE name = 'Bob Barker')
BEGIN
    SELECT 'TRUE' as Result1;
    SELECT CASE WHEN EXISTS (SELECT * 
                             FROM usersTbl 
                             WHERE name = 'Bob Barker'
                             AND active = 1)
                THEN (SELECT name
                      FROM usersTbl 
                      WHERE name = 'Bob Barker'
                      AND active = 1)
                ELSE 'FALSE'
                END as Result2;
END

IF NOT EXISTS (SELECT * FROM usersTbl WHERE name = 'Bob Barker')
BEGIN
   SELECT 'FALSE' as Result1;
END

Answer 3

这可能适合你。

SELECT 
    *
FROM subTable1
WHERE
    st.value = 'Value'
    AND st.restrictiveValue = 'restrictiveValue'
    AND (SELECT COUNT(*) AS resultCount FROM subTable1 st WHERE st.value = 'Value') != 0

SELECT COUNT(*) AS resultCount FROM subTable1 st WHERE st.value = 'Value'

如果您不希望它返回空表，您可能需要查看this question.中提到的动态SQL

MS SQL选择案例查询true或false然后执行另一个SELECT查询

3 个答案: