for循环后从DB中检索数据到数据集 [英] Retrieving Data to dataset from DB after for loop

问题描述

大家好，

我需要在循环中传递id的查询（即for（int i = 0; i< 45; i ++）
每次迭代后
我需要在dataSet中检索数据。这样我就可以在循环后查看所有数据。

ex：

Hi everyone,
I've a query to which i need to pass the id in loop,(i.e., for(int i=0;i<45;i++)
after every iteration i need that retrieved data in dataSet. so that i can view that all data after the loop.
ex:

for (int i = 0; i < 45; i++)
{
    string str = " SELECT * from Table1 where id='"+i+"'";


    SqlCommandcmd = new SqlCommand(str, conn);

    SqlDataAdapter adp = new SqlDataAdapter(cmd);

    DataTable dt = new DataTable();
    adp.Fill(dt);

    gridview1.DataSource = dt;
    gridview1.DataBind();
}

推荐答案

这样做一次只能获得一个ID。



如果您使用的是SQL Server，则可以使用表值参数。

使用获取循环用ID填充DataTable，然后将它们作为参数传递给查询。



SQL Server 2008用户定义的表类型和表值参数 [ ^ ]

Doing it that way will get you only one ID at a time.

If you are using SQL Server, you can use a Table-Valued Parameter.
Use your for loop to fill a DataTable with the IDs, then pass them as a parameter to the query.

SQL Server 2008 User Defined Table Types and Table-Valued Parameters[^]

您可以通过单次调用数据库来实现此目的。查看下面的代码块。我做了两个小改动，这样可以用更少的时间给出正确的结果。

You can achieve this with single call of database. Review below block of code. I make two small change and this will give proper result with less time.

string strIds = string.Empty;

for (int i = 0; i < 45; i++)
{
	strIds = strIds == string.Empty ? "'" + i.ToString() + "'" : (",'" + i.ToString() + "'");
}

string str = " SELECT * from Table1 where id IN (" + strIds + ")";

SqlCommandcmd = new SqlCommand(str, conn);

SqlDataAdapter adp = new SqlDataAdapter(cmd);

DataTable dt = new DataTable();
adp.Fill(dt);

gridview1.DataSource = dt;
gridview1.DataBind();

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