我們可以用行數替換列的所有值嗎？

Question

我有一個查詢

select name,name_order from name_table where dept_id=XXX; 

和結果集中是

+------------+--------+ 
| name_order | name | 
+------------+--------+ 
| 0  | One | 
| 1  | Two | 
| 2  | Three | 
| 3  | four | 
| 6  | five | 
| 9  | six | 
+------------+--------+ 

我必須更新用於的dept_id的name_order，以這樣的方式使得它們從0和 遞增開始（針對的dept_id只）
注：name_order是不是索引
的出落得應該像

+------------+--------+ 
| name_order | name | 
+------------+--------+ 
| 0  | One | 
| 1  | Two | 
| 2  | Three | 
| 3  | four | 
| 4  | five | 
| 5  | six | 
+------------+--------+ 

我試圖分析功能ROWNUMBER（），它並沒有幫助提前

update name_table set name_order = (
ROW_NUMBER() OVER (PARTITION BY dept_id ORDER BY name_order)-1 
) 
where dept_id=XXX order by name_order 

感謝 -R

Answer 1

UPDATE NAME_TABLE A 
SET NAME_ORDER=(
    SELECT R 
    FROM (SELECT NAME,ROW_NUMBER() OVER(ORDER BY NAME_ORDER) R 
       FROM NAME_TABLE) B 
    WHERE A.NAME=B.NAME); 

http://www.sqlfiddle.com/#!4/6804a/1

UPDATE NAME_TABLE A 
SET NAME_ORDER=(
    SELECT R 
    FROM (SELECT NAME,DEPT_ID,ROW_NUMBER() OVER(PARTITION BY DEPT_ID ORDER BY NAME_ORDER)-1 R 
       FROM NAME_TABLE) B 
    WHERE A.NAME=B.NAME AND A.DEPT_ID=B.DEPT_ID /*AND A.DEPT_ID=XXX*/); 

添加有關條件dept_id爲。謝謝路人。

Answer 2

SET @rownum:=0; SELECT @rownum:=@rownum+1 AS name_order, names from name_table where dept_id=XXX; 

working fine on mysql. 

Answer 3

您可以用merge command

MERGE INTO name_table dst 
USING (SELECT t.*, row_number() over (partition BY dept_id ORDER BY name_order) -1 n 
     FROM name_table t) src 
ON (dst.dept_id = src.dept_id AND dst.name = src.name) 
WHEN MATCHED THEN UPDATE SET Dst.name_order = src.n; 

Here is a sqlfiddle demo

做，但爲什麼你想與值的列，你可以在查詢？