SQL中的案例陳述和ORP

Question

有人可以請告知下面嗎？我有一些我想要使用的字段，並將它們組合在一列中獲取數據。我正在使用下面的案例陳述，但沒有得到我期望的結果。

CASE 
WHEN m.u_hearing = 1 THEN 'Hearing' 
WHEN m.u_learning_reading_diff = 1 THEN 'Learning or reading Difficulty' 
WHEN m.u_long_term_ill = 1 THEN 'Long Term Illness' 
WHEN m.u_mental_illness = 1 THEN 'Mental Illness' 
WHEN m.u_mobility = 1 THEN 'Mobility' 
WHEN m.u_physical_coordination = 1 THEN 'Physical Co-ordination' 
WHEN m.u_physical_dis = 1 THEN 'Physical Disability' 
WHEN m.u_red_physical_cap = 1 THEN 'Reduced_physical_capacity' 
WHEN m.u_speech = 1 THEN 'Speech' 
WHEN m.u_vision = 1 THEN 'Vision' 
WHEN m.u_other_dis = 1 THEN 'Other_Disability' 
WHEN (m.u_hearing = 1 AND (m.u_learning_reading_diff = 1 OR (m.u_speech = 1))) THEN 'Multiple' 

這是不給結果作爲是否有與有多個領域的話，我想多回來，我想最後的語句，但現在看來，這是撿尚屬首例。

Answer 1

把「最困難」的條件首先

case WHEN m.u_hearing = 1 AND (m.u_learning_reading_diff = 1 OR m.u_speech = 1) THEN 'Multiple' 
    WHEN m.u_hearing = 1 THEN 'Hearing' ... 

因爲case停止在該是true

Answer 2

當使用CASE語句，他們將在您指定的順序運作的首要條件。

因此，如果m.u_Hearing = 1那麼它會停在第一行，並沒有達到底部。

這將適用於您所需的內容，但請按您喜歡的順序列出。

CASE 
WHEN (m.u_hearing = 1 AND (m.u_learning_reading_diff = 1 OR (m.u_speech = 1))) THEN 'Multiple' 
WHEN m.u_hearing = 1 THEN 'Hearing' 
WHEN m.u_learning_reading_diff = 1 THEN 'Learning or reading Difficulty' 
WHEN m.u_long_term_ill = 1 THEN 'Long Term Illness' 
WHEN m.u_mental_illness = 1 THEN 'Mental Illness' 
WHEN m.u_mobility = 1 THEN 'Mobility' 
WHEN m.u_physical_coordination = 1 THEN 'Physical Co-ordination' 
WHEN m.u_physical_dis = 1 THEN 'Physical Disability' 
WHEN m.u_red_physical_cap = 1 THEN 'Reduced_physical_capacity' 
WHEN m.u_speech = 1 THEN 'Speech' 
WHEN m.u_vision = 1 THEN 'Vision' 
WHEN m.u_other_dis = 1 THEN 'Other_Disability' 

Answer 3

據我所知，你不能在另一個「時，」像再次使用您的第一條語句的

WHEN m.u_hearing = 1 THEN 'Hearing' 

上述情況嘗試使用否則，如果它是在結束工作，可行的爲您服務。

Else 'Multiple'