如何从表复制下表记录和使用存储过程的SQL Server

Question

插入到相同的表，我有：

我只想复制那些从0版本记录及其student_id数据是永远在版本1中重复，这意味着不变的记录。我想将所有复制的记录插入到版本为1的同一张表。什么是存储过程。

Answer 1

您可以通过执行选择记录：

select t.* 
from t 
where t.version = 0 and 
     not exists (select 1 
        from t t2 
        where t2.student_id = t.student_id and t2.version = 1 
       ); 

剩下的只是一个insert。

Answer 2

使用group by和having max(version) = 0：

insert into student_name (student_id, student_name, version) 
select student_id, max(student_name), 1 
from student_name 
group by student_id 
having max(version) = 0 

---

被存储的过程中，采取了version一个参数，即插入了学生没有该版本记录谁记录：输出行是插入：

create procedure dbo.insert_new_version (@version int) as 
begin; 
    set nocount, xact_abort on; 

    insert into student_name (student_id, student_name, version) 
    output inserted.* 
    select 
     student_id 
    , student_name = max(student_name) 
    , version = @version 
    from student_name 
    group by student_id 
    having max(version) < @version 
end; 

rextester演示：http://rextester.com/JSTNI40605

个

回报：

+-----------+------------+--------------+---------+ 
| record_id | student_id | student_name | version | 
+-----------+------------+--------------+---------+ 
|  11 |   3 | ccc   |  1 | 
+-----------+------------+--------------+---------+ 

Answer 3

您可以选择和插入这样

Insert INTO tableName select t1.student_Id, t1.student_name,1 from tablename t1 
where t1.version = 0 and not exists 
(select 1 from tablename t2 where t2.student_id = t.student_id and t2.version = 1); 

Answer 4

您可以通过LEFT试试这个加入：

INSERT INTO TBL SELECT T1.record_id，T1.student_Id ，T1.student_name，1 FROM tbl T1 LEFT JOIN tbl T2 ON T1.student_Id = T2.student_Id AND T2.version = 1 WHERE T1.version = 0 AND T2.record_id IS NULL

Answer 5

我建议使用while循环遍历表并确定需要复制的项目，然后对这些值进行 评估，如果它们符合重新插入的标准并且然后插入它们。

您的代码应该如下所示。添加CREATE PROC部分，编辑表名适用 （警告：我写了这对记事本，所以如果你得到了一些错误，只是尝试解决这些问题）

DECLARE @counter int = 0, @row_Count int = 0, @currentId int, 
@currentName nvarchar(100), @version int, @current_Student_id int 

SET @row_Count = (SELECT COUNT(record_Id) from yourTable) 

WHILE @counter <= @row_Count 
BEGIN 
SET @currentId = (SELECT record_Id FROM (SELECT row_number() over (order by id) 
      AS RowNum, record_Id FROM yourTable) sub WHERE RowNum=@counter) 

SET @currentName = (SELECT student_name FROM yourTable WHERE record_Id = @currentId) 
SET @current_Student_id = (SELECT student_id FROM yourTable WHERE record_Id = @currentId) 
SET @version = (SELECT version FROM yourTable WHERE record_Id = @currentId) 

--USE IF to check if the current version is 0 and the student ID has not been inserted already 

IF (SELECT COUNT(record_Id) FROM yourTable WHERE student_id = @current_Student_id AND version = 1) < 1 
      AND @version = 0 
BEGIN 
INSERT INTO yourTable (student_id, student_name, version) 
    VALUES 
(
@current_Student_id, 
@currentName, 
1 
) 
END 

SET @counter = @counter + 1; 
END