在未輸入日期的日期字段上過濾

Question

我需要將字段過濾爲日期，但該字段未輸入日期或日期時間。

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 

它拋出一個錯誤（Conversion failed when converting datetime from character string），除非我的評論的最後一行。
據我所知，SQL優化器首先在每個valeur字段上執行CONVERT函數，然後在其他條件下過濾，然後進行連接。所以它會嘗試CONVERT字段中的「常規」文本，所以它當然不起作用。

我嘗試過一個CTE，但它做的事情完全一樣。

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 

你有什麼想法，這將讓我切切第一返回一個包含日期字段，然後過濾他們？

該表的設計類似（縮短清晰度）：

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 
) 

感謝

Answer 1

我認爲你需要使用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

試試這個：我知道這個工程的MSSQL和MySQL，但不知道什麼DB烏爾使用

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

嘗試的HAVING子句中，並使用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

下面的查詢應該做的工作，無需轉換錯誤。注意：無效的時間戳將被忽略。

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

做了一些改變，這將返回預期的結果。

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'