獲取具有特定條件的行數

Question

我想獲取表中存在的一行的計數。

+---+----+
|id |name|
+---+----+
|100|a   |
+---+----+
|201|b   |
+---+----+
|302|c   |
+---+----+
|403|d   |
+---+----+
|504|e   |
+---+----+

在上表中，我希望輸出為4（即，該行的計數）。 我有'd'值，必須編寫查詢以將輸出獲取為4 ，其中name = d

我認為代碼將如下所示，

select count(*) ......

Answer 1

SELECT ROW_NUMBER() OVER(ORDER BY id) FROM yourtable WHERE name='d'

MySQL版本

SET @rank=0;
SELECT   @rank := @rank+1 AS rank
FROM     yourtable WHERE name='d'
ORDER BY id asc

Answer 2

獲取行號

SELECT ROW_NUMBER() OVER(ORDER BY id) from table WHERE name='d'

要獲取符合您條件的行數，請使用以下查詢

select count(*) as count from table where name = 'b'

Answer 3

如果我正確理解您的要求，那么此查詢就是您想要的：

set @row_number = 0; 
select @row_number := @row_number + 1 as row_number,name FROM table_name;

Answer 4

@vinoth我認為@Pragmatist答案將為您工作。 只需將此子句添加到他的查詢中：

set @row_number = 0; 
select @row_number := @row_number + 1 as row_number,name FROM table_name Where name='b';

Answer 5

請嘗試以下。 MS SQL是一個經過測試的查詢，我剛剛轉換為mysql。 希望您可以根據需要進行修改。

    SET @rank=0;
    SELECT * FROM Table1 T1
    INNER JOIN(
           SELECT   @rank := @rank+1 AS rank, ID
           FROM     Table1
           ORDER BY id asc) temp ON temp.ID = T1.ID
    WHERE T1.name = 'd' 

MS SQL查詢將

SELECT * FROM Table1 T1
INNER JOIN(SELECT id, ROW_NUMBER() OVER (Order by id) AS RowNumber from Table1) temp ON   temp.ID = T1.ID
WHERE T1.name = 'd'