如何从表中读取每一行并与Asp.Net中的另一个表进行比较（Csharp） [英] How Do I Read Each Row From A Table And Compare With Another Table In Asp.Net(Csharp)

问题描述

使用company_table读取一行表emplyee_table



匹配（类似）

EmpID，Name，Amount_ID和年份



检查具有相同匹配的每行的金额EmpID，Name，Amount_ID和年份不超过company_table金额

Read one row of table emplyee_table with company_table

matching(similar)
EmpID, Name , Amount_ID and year

check the "amount" of each row having same matching EmpID, Name , Amount_ID and year doesn't exceed with company_table "amount"

if the amount of employee_table exceed company_table.. (if e.amt>c.amt)
{
    validatiion- that row will not update
}
else if the amount of employee_table is same  company_table (if e.amt=c.amt)
{
    update that particular row into (company_details_table)
}
else if the amount of employee_table is same  company_table (if e.amt<c.amt)
{
    update that particular row into (company_details_table)
}

推荐答案

如果SQL命令是您的问题你可以从这里开始： SQL教程 [ ^ ]

具体更新命令： SQL UPDATE语句 [ ^ ]



对于c＃部分，你应该查找MSDN SqlConnection [ ^ ]和 SqlCommand [ ^ ]



你会在那里找到一些例子。



还有很多其他来源： C＃SqlCommand [ ^ ]

If SQL commands is your problem you can start here: SQL Tutorial[^]
Update command specifically: SQL UPDATE Statement[^]

For the c# part you should look up MSDN for SqlConnection[^] and SqlCommand[^]

You will find some examples there.

There are plenty of other sources too: C# SqlCommand[^]

好的。

我在网络上工作..在局域网中它将是..

它将逐一读取每一行..会有很多数据..在table1 n table2中。一旦找到匹配字段并检查table1的数量是否超过表2的数量，那么它将仅更新那些未超过该数量的行。

并且它在另一个表3中更新，列名称已经过验证。该金额已正确更新为该员工。

好​​的，这将是缓慢的。非常慢。

每次获取行都涉及一个局域网会话，在SQL端处理，数据返回到C＃，在那里处理，另一次会话再次返回到SQL服务器。如果你做了很多行，那就太慢了。

用SQL做。

设置一个事务，并在其中做两个更新命令。



假设您有三张桌子：

Table1

id，amt，updates

Table2

id，t1Id，amt

表3

id，t1Id，已验证

然后这两个更新非常简单：

Alright.
I am working in a web based.. In a LAN it will be..
It will read each row one by one.. There will be many data.. In table1 n table2. Once it find the matching field and check the amount that amout of table1 is not exceeding amount of table 2 then it will update those rows only which has not exceeded the amount.
And it wi update in a another table 3 that column name as verified. That amount is correctly updated to those employee.
Ok, that will be slow. Horribly slow.
Each row fetch involves a lan conversation, processing on the SQL side, data back to C#, processing there, and another conversation back to the SQL server again. If you are doing many rows, that's pretty damn slow.
Do it in SQL.
Set up a transaction, and do two update commands inside it.

Assuming you have three tables:
Table1
id, amt, updates
Table2
id, t1Id, amt
Table3
id, t1Id, verified
Then the two updates are pretty trivial:

UPDATE t1
SET t1.updates = t1.updates + 1
FROM Table1 t1
JOIN Table2 t2 ON t1.id = t2.t1Id
JOIN Table3 t3 ON t1.id = t3.t1Id
WHERE t1.amt < t2.amt

和

And

UPDATE t3
SET t3.verified = 'Yes'
FROM Table1 t1
JOIN Table2 t2 ON t1.id = t2.t1Id
JOIN Table3 t3 ON t1.id = t3.t1Id
WHERE t1.amt < t2.amt

让SQL以最有效的方式解决这个问题 - 它非常擅长！



我设置了一个SP，在事务中包含那两个（所以如果它失败则没有任何改变）并且只是从C＃执行它。

什么都没有留下SQL，以及处理由最擅长的软件完成。

Will let SQL work out the most efficient way to do that - and it's pretty good at it!

I'd set up an SP, containing those two inside a transaction (so if it fails there is nothing changed) and just execute that from the C#.
Nothing leaves SQL, and the processing is done by the software that's best at it.

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