Question

是否有可能从select中进行选择-嵌套结果临时表而不是函数而不是过程中使用的原始表？

这很完美：

SELECT ID, PAR1, PAR2 INTO tempTABLE 
FROM originalTABLE
WHERE ..CONDITIONS..

SELECT TOP 1 (tbl1.PAR2 + tbl2.PAR2 + tbl3.PAR2) AS FinalResult
FROM tempTable tbl1
INNER JOIN tempTable tbl2 on tbl2.PAR1 > tbl1.PAR1
INNER JOIN tempTable tbl3 on tbl3.PAR1 > tbl2.PAR1
ORDER BY tbl1.PAR2 + tbl2.PAR2 + tbl3.PAR2

DROP TABLE tempTable

但是由于INSERT语句，我无法在函数中使用它，所以我尝试这样：

SELECT (tbl1.PAR2 + tbl2.PAR2 + tbl3.PAR2) AS FinalResult 
FROM ((SELECT ID, PAR1, PAR2 FROM originalTABLE
WHERE ..CONDITIONS.) AS tempTable) tbl1
    INNER JOIN tempTable tbl2 on tbl2.PAR1 > tbl1.PAR1
    INNER JOIN tempTable tbl3 on tbl3.PAR1 > tbl2.PAR1
    ORDER BY tbl1.PAR2 + tbl2.PAR2 + tbl3.PAR2

但是失败了。

Answer 1

这应该可以正常工作：

SELECT (tbl1.PAR2 + tbl2.PAR2 + tbl3.PAR2) AS FinalResult 
FROM (SELECT ID, PAR1, PAR2 FROM originalTABLE
WHERE ..CONDITIONS.
     ) AS tempTable tbl1 JOIN
     tempTable tbl2
     ON tbl2.PAR1 > tbl1.PAR1 JOIN
     tempTable tbl3 
     ON tbl3.PAR1 > tbl2.PAR1
ORDER BY tbl1.PAR2 + tbl2.PAR2 + tbl3.PAR2;

子查询仅使用一组括号。

请注意，您也可以使用：

ORDER BY FinalResult

在ORDER BY子句中可以识别列别名。

Answer 2

您可以直接用CTE替换时态表：

with tempTable as (
  SELECT ID, PAR1, PAR2 INTO tempTABLE 
  FROM originalTABLE
  WHERE ..CONDITIONS..
)
SELECT TOP 1 (tbl1.PAR2 + tbl2.PAR2 + tbl3.PAR2) AS FinalResult
FROM tempTable tbl1
INNER JOIN tempTable tbl2 on tbl2.PAR1 > tbl1.PAR1
INNER JOIN tempTable tbl3 on tbl3.PAR1 > tbl2.PAR1
ORDER BY tbl1.PAR2 + tbl2.PAR2 + tbl3.PAR2

SQL FUNCTION中的嵌套临时表，例如select from（select ..）

2 个答案: