在未输入日期的日期字段上过滤

Question

我需要将字段过滤为日期，但该字段未输入日期或日期时间。

SELECT champ_save_id, element_id, valeur 
FROM g_champ_save AS cs 
INNER JOIN g_champ AS c ON cs.champ_id = c.champ_id 
WHERE cs.valeur <> '' AND NOT cs.valeur IS NULL 
AND c.champ_code = 'qualif_valide_qualif_fin' 
AND CONVERT(datetime, cs.valeur, 103) <= @filterdate 

它抛出一个错误（Conversion failed when converting datetime from character string），除非我的评论的最后一行。
据我所知，SQL优化器首先在每个valeur字段上执行CONVERT函数，然后在其他条件下过滤，然后进行连接。所以它会尝试CONVERT字段中的“常规”文本，所以它当然不起作用。

我尝试过一个CTE，但它做的事情完全一样。

WITH valeurs AS (
    SELECT champ_save_id, element_id, valeur 
    FROM g_champ_save AS cs 
    INNER JOIN g_champ AS c ON cs.champ_id = c.champ_id 
    WHERE cs.valeur <> '' AND NOT cs.valeur IS NULL 
    AND c.champ_code = 'qualif_valide_qualif_fin' 
    AND ISDATE(convert(datetime, cs.valeur, 103)) = 1 
) 
SELECT * FROM valeurs 
WHERE CONVERT(datetime, valeur, 103) <= @filterdate 

你有什么想法，这将让我切切第一返回一个包含日期字段，然后过滤他们？

该表的设计类似（缩短清晰度）：

CREATE TABLE g_champ (
    champ_id int IDENTITY(1,1) NOT NULL, 
    type_id int NOT NULL, -- defines the type : text, checkbox, date, etc 
    champ_code nvarchar(50) NULL, 
    champ_label nvarchar(max) NULL 
) 

CREATE TABLE g_champ_save (
    champ_save_id int IDENTITY(1,1) NOT NULL, 
    champ_id int NOT NULL, 
    element_id int NULL, 
    valeur nvarchar(max) NULL 
) 

感谢

Answer 1

我认为你需要使用IsDate：

SELECT champ_save_id, element_id, valeur 
FROM g_champ_save AS cs 
INNER JOIN g_champ AS c ON cs.champ_id = c.champ_id 
WHERE cs.valeur <> '' AND NOT cs.valeur IS NULL 
AND c.champ_code = 'qualif_valide_qualif_fin' 
AND CONVERT(datetime, case IsDate(cs.valeur) when 1 then cs.valeur end, 103) 
    <= @filterdate 

Answer 2

试试这个：我知道这个工程的MSSQL和MySQL，但不知道什么DB乌尔使用

SELECT champ_save_id, element_id, valeur 
FROM g_champ_save AS cs 
INNER JOIN g_champ AS c ON cs.champ_id = c.champ_id 
WHERE cs.valeur <> '' AND NOT cs.valeur IS NULL 
AND c.champ_code = 'qualif_valide_qualif_fin' 
AND Date(cs.valeur) <= @filterdate 

Answer 3

尝试的HAVING子句中，并使用IS NOT NULL不NOT cs.valeur IS NULL

SET DATEFORMAT dmy; 
GO 
SELECT champ_save_id, element_id, valeur 
    FROM g_champ_save AS cs INNER JOIN g_champ AS c 
     ON cs.champ_id = c.champ_id 
WHERE cs.valeur <> '' AND 
     cs.valeur IS NOT NULL AND 
     c.champ_code = 'qualif_valide_qualif_fin' 
HAVING CONVERT(datetime, cs.valeur, 103) <= @filterdate; 

Answer 4

下面的查询应该做的工作，无需转换错误。注意：无效的时间戳将被忽略。

SELECT 
champ_save_id, element_id, valeur 
FROM 
(
SELECT champ_save_id, element_id, valeur 
FROM g_champ_save AS cs 
INNER JOIN (SELECT c.champ_id FROM g_champ c WHERE c.champ_code = 'qualif_valide_qualif_fin') AS c ON cs.champ_id = c.champ_id 
WHERE cs.valeur <> '' AND NOT cs.valeur IS NULL AND ISDATE(cs.valeur) 
) sub 
WHERE CONVERT(datetime, cs.valeur, 103) <= @filterdate 

更新

做了一些改变，这将返回预期的结果。

SET DATEFORMAT dmy;

SET DATEFORMAT dmy; 

SELECT 
champ_save_id, element_id, valeur, CONVERT(datetime, sub.valeur, 103) 
FROM 
(
SELECT champ_save_id, element_id, valeur 
FROM (SELECT 1 champ_id, 1 champ_save_id, 1 element_id, '30/1/2012' valeur) AS cs 
INNER JOIN (SELECT c.champ_id FROM (SELECT 1 champ_id, 'qualif_valide_qualif_fin' champ_code) c WHERE c.champ_code = 'qualif_valide_qualif_fin') AS c ON cs.champ_id = c.champ_id 
WHERE cs.valeur <> '' AND NOT cs.valeur IS NULL AND ISDATE(cs.valeur) = 1 
) sub 
WHERE CONVERT(datetime, sub.valeur, 103) <= '01/02/2012'