哪裏條件不適用於IN子句

Question

我有一個查詢。在這個查詢中，我使用了一個子查詢來從具有不同條件的同一個表中獲取數據，並且在主要查詢中，我提到了用於在子查詢中獲取數據的ID，並將條件表示爲在主查詢中考慮與ID不應該是空的。如果我在主查詢中使用帶有IN子句的單個ID，我的查詢可以正常工作，但是如果我在主查詢中使用多個ID並添加值不應該爲空的子句，則查詢不會給我所需的結果。這是我的查詢

SELECT e.id AS `Personal Number`, 
e.date AS `Date`, 
CONCAT(ep.firstname,' ',ep.lastname) AS `Employee Name`, 
IF(ep.sex='M','Male','Female') AS sex, 
DATE_FORMAT(p.birthdate,'%m/%d/%Y')AS birthdate, 
(SELECT `value` FROM employee_data WHERE history=87 AND DATE=e.date) AS `A`, 
(SELECT `value` FROM employee_data WHERE history=603 AND DATE=e.date) AS `B`, 
(SELECT `value` FROM employee_data WHERE history=82 AND DATE=e.date) AS `C`, 
(SELECT `value` FROM employee_data WHERE history=86 AND DATE=e.date) AS `D` 
FROM tbl e 
INNER JOIN employee ep ON e.id = ep.id 
INNER JOIN tbl2 ap ON ap.date=e.date 
INNER JOIN employee_data AS phd ON e.date = phd.date 
WHERE (phd.history IN(82,87,603,86) AND phd.value!='') AND ap.date BETWEEN '2013-01-01' AND '2013-09-01'AND e.status!='cancelled'. 

我不知道如何處理這個查詢。任何人都可以幫忙在此先感謝

Answer 1

由於您在select子句中使用篩選器獲取值，請在select子句中執行group by並獲取max（）值。

max (SELECT `value` FROM employee_data WHERE history=87 AND DATE=e.date) AS `A`, 
max (SELECT `value` FROM employee_data WHERE history=603 AND encounter_nr=e.encounter_nr)  AS `B`, 
max (SELECT `value` FROM employee_data WHERE history=82 AND encounter_nr=e.encounter_nr) AS `C`, 
max (SELECT `value` FROM employee_data WHERE history=86 AND encounter_nr=e.encounter_nr) AS `D` 
FROM 

Answer 2

這是你的問題。當您有where子句時，您的查詢產生四行。但是，我懷疑你只是期待一行，或者至少每行只有一行。

我想這是你想要的查詢：

SELECT e.id AS `Personal Number`, e.date AS `Date`, 
     CONCAT(ep.firstname,' ',ep.lastname) AS `Employee Name`, 
     IF(ep.sex='M','Male','Female') AS sex, 
     DATE_FORMAT(p.birthdate,'%m/%d/%Y') AS birthdate, 
     max(case when history = 87 then value end) as A, 
     max(case when history = 603 then value end) as B, 
     max(case when history = 82 then value end) as C, 
     max(case when history = 86 then value end) as D 
FROM tbl e INNER JOIN 
    employee ep 
    ON e.id = ep.id INNER JOIN 
    tbl2 ap ON ap.date = e.date INNER JOIN 
    employee_data phd 
    ON e.date = phd.date 
WHERE phd.history IN (82, 87, 603, 86) AND phd.value <> '' AND 
     ap.date BETWEEN '2013-01-01' AND '2013-09-01' AND 
     e.status <> 'cancelled' 
group by e.id; 

這應返回一行爲每個員工。

編輯：

它發生在我身上，你可能不想要聚合。您可以通過刪除在外部查詢的加盟employee_data按照你原來的做法：

SELECT e.id AS `Personal Number`, e.date AS `Date`, 
     CONCAT(ep.firstname,' ',ep.lastname) AS `Employee Name`, 
     IF(ep.sex='M','Male','Female') AS sex, 
     DATE_FORMAT(p.birthdate,'%m/%d/%Y') AS birthdate, 
     (SELECT `value` FROM employee_data WHERE history=87 AND DATE=e.date) AS `A`, 
     (SELECT `value` FROM employee_data WHERE history=603 AND DATE=e.date) AS `B`, 
     (SELECT `value` FROM employee_data WHERE history=82 AND DATE=e.date) AS `C`, 
     (SELECT `value` FROM employee_data WHERE history=86 AND DATE=e.date) AS `D` 
FROM tbl e INNER JOIN 
    employee ep 
    ON e.id = ep.id INNER JOIN 
    tbl2 ap ON ap.date = e.date 
WHERE ap.date BETWEEN '2013-01-01' AND '2013-09-01'AND e.status <> 'cancelled' 
HAVING A <> '' and B <> '' and C <> '' and D <> ''; 

的having子句是一個MySQL的技巧，可以讓你參考列別名from子句。這並不意味着在這種情況下的聚合。

如果您有索引employee_data(history, date)，您會這樣做。