我有三列 [英] i have three columns

问题描述

column1 column2 column3

2 1133 assam

3 2244 delhi

现在假设从combobox我选择1133那么它将如何比较数据库已经在数据库中的值。

column1 column2 column3
2 1133 assam
3 2244 delhi
now suppose from combobox i have select 1133 then how it will compare database values that it is already in database.

推荐答案

尝试：

Try:

SELECT COUNT(*) FROM MyTable WHERE MyColumn2=1133

如果它返回零，则它不在DB中。

If it returns zero, it's not in the DB.

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
   //send DB Call and get the value from database
   
if (comboBox1.SelectedItem.ToString()== "DB value") // Compare here
   {
    
   }
  
}

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