如何從兩個條件的表中選擇數據

Question

我需要從帶有聯合的兩個條件的表中選擇數據，或者為表選擇數據

    name       special

    Deepak         s
    mukesh         v
    dinesh         s
    girgesh        v
    Deepak         s
    mukesh         v
    dinesh         s
    girgesh        v
    Deepak         s
    mukesh         v
    dinesh         s
    girgesh        v

查詢以獲取數據...

SELECT NAME FROM  student WHERE special = "s" LIMIT 2
UNION 
SELECT NAME FROM student WHERE special = "v"  LIMIT 2

但它只給出聯合之前的第一個條件...如何從單個表中獲取兩個不同的條件數據

Answer 1

根據MySQL在UNION上的文檔 ：

要將ORDER BY或LIMIT應用於單個SELECT，請將子句放在包圍SELECT的括號內

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因此，您想使用：

(SELECT NAME FROM  student WHERE special = "s" LIMIT 2)
UNION 
(SELECT NAME FROM student WHERE special = "v"  LIMIT 2)

Answer 2

正如@Burned Buffen在評論中提到的：

SELECT NAME FROM  student WHERE special = "s" or special = "v" LIMIT 2