如何使用文本框传递表名称的参数 [英] How Do I Pass Parameter For Table Name Using Textbox

问题描述

嗨


在这里，我传递了一张Table Giving表的名字。



但是现在我想要通过表名文本框。我试过很多方法来传递表名的值。



请帮助代码。



我猜它会起作用

  string  tablename = txtSearch.Text; 
 字符串 query =  从数据库中选择*其中tablename = @ tablename; 

什么是确切查询。



如何修改它以便从文本框中读取。





< pre lang =c＃> private void btnSearch_Click（ object sender，EventArgs e）
{
connection.Open（）;
尝试
{

OleDbCommand command = new 的OleDbCommand（）;
command.Connection = connection;
string query = 从TestTable中选择* ;
command.CommandText = query;
OleDbDataAdapter da = new OleDbDataAdapter（command）;
DataTable dt = new DataTable（）;
da.Fill（dt）;
dataGridView1.DataSource = dt;

command.ExecuteNonQuery（）;


}
catch （Exception ex）
{
MessageBox.Show（ex的ToString（））;
}
connection.Close（）;
}

解决方案

如果你想要的只是更改表的名称并从表中获取所有列，您可以使用 String.Format [ ^ ]方法。



示例：

 字符串 query = 字符串 .Format（ 选择*从{0}，txtSearch.Text）; 

如果您想要更高级的查询，您应该关注解决方案1中的建议。

不确定你想要什么，但是......



MS Access提供了一种创建方法 pa rametrized query [ ^ ]。

 PARAMETERS [myParam]  CHAR ; 
  SELECT < FieldList> 
  FROM  TableName 
  WHERE  FieldName = [myParam]; 

现在，您需要创建 OleDbCommand with parameters（s） [ ^ ]。使用 AddWithValue [ ^ ]方法：）

谢谢Sir先生工作良好。

非常感谢你。





private void btnSearch_Click（object sender，EventArgs e）

{

connection.Open（ ）;

尝试

{



OleDbCommand command = new OleDbCommand（）;

command.Connection = connection;

string tablename = Txt_Search.Text;

String query = String.Format（Select * from {0}，Txt_Search.Text ）;

command.CommandText = query;



OleDbDataAdapter da = new OleDbDataAdapter（command）;

DataTable dt = new DataTable（）;

da.Fill（dt）;

dataGridView1.DataSource = dt;



// command.ExecuteNonQuery（）;





}

catch（exception ex）

{

MessageBox.Show（ex.ToString（））;

}

connection.Close（）;

}

Hi
Here I passed a Table Giving table's Name.

But Now i want to Pass Table's Name through textbox. I tried in many ways to pass values for table's name.

Please help with code.

I am guessing It would work as

string tablename = txtSearch.Text;
String query = "Select * from Database Where tablename=@tablename";

What is exact query.

How to modify it to read from textbox.

private void btnSearch_Click(object sender, EventArgs e)
{
connection.Open();
try
{

OleDbCommand command = new OleDbCommand();
command.Connection = connection;
string query = "Select * from TestTable";
command.CommandText = query;
OleDbDataAdapter da = new OleDbDataAdapter(command);
DataTable dt = new DataTable();
da.Fill(dt);
dataGridView1.DataSource = dt;

command.ExecuteNonQuery();


}
catch(Exception ex)
{
MessageBox.Show(ex.ToString());
}
connection.Close();
}

解决方案

If the only thing you want is to change the name of the table and get all columns from the table, you can use the String.Format[^] method.

Example:

String query = String.Format("Select * from {0}", txtSearch.Text);

If you want a more advanced query you should follow the advice in Solution 1.

Not sure what you want, but...

MS Access provides a way to create parametrized query[^].

PARAMETERS [myParam] CHAR;
SELECT <FieldList>
FROM TableName
WHERE FieldName = [myParam];

Now, you need to create OleDbCommand with parameter(s)[^]. It's quite simple with AddWithValue[^] method :)

Thank You Sir Its working Good.
Thank You So Much.


private void btnSearch_Click(object sender, EventArgs e)
{
connection.Open();
try
{

OleDbCommand command = new OleDbCommand();
command.Connection = connection;
string tablename = Txt_Search.Text;
String query = String.Format("Select * from {0}", Txt_Search.Text);
command.CommandText = query;

OleDbDataAdapter da = new OleDbDataAdapter(command);
DataTable dt = new DataTable();
da.Fill(dt);
dataGridView1.DataSource = dt;

// command.ExecuteNonQuery();


}
catch(Exception ex)
{
MessageBox.Show(ex.ToString());
}
connection.Close();
}

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