如何獲得的行數與條件

Question

我有一個表像這樣

id student teacher 
10  a  b 
11  c  b 
12  d  c 
13  e  b 

學生的「e」是3TH學生，其導師爲「B」。 如何使用一個查詢來獲取此信息？

Answer 1

你可以那樣做：

SELECT * FROM (
    SELECT @row := @row + 1 as row, t.* FROM student_table t, (SELECT @row := 0) r where t.teacher ='b' 
) s where student = 'e' 

Answer 2

非常接近於Secator

SELECT * 
FROM (
    SELECT (@row := @row + 1) AS rank, student 
    FROM my_table, 
    (SELECT @row := 0) q 
    WHERE teacher = 'b' 
) s 
WHERE student = 'e'