当我使用以下代码时，循环会迭代两次，并且我收到错误消息，因为“变量名 '@projectName1' 已被声明。变量名在查询批处理或存储过程中必须是唯一的。” 并在 datagridview 和表中重置表的所有值。实际上，我想通过选择单元格来更新表单本身的 DataGridView，它也应该在数据库中反映相同的内容。
private void btnUpdate_Click(object sender, EventArgs e)
{
SqlConnection con = Helper.getconnection();
con.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = con;
string myCmd = string.Empty;
foreach (DataGridViewRow myDgrow in dataGridView2.Rows)
{
myCmd = "Update Details set ProjectName='" + myDgrow.Cells["ProjectName"].Value + "', Description = '" + myDgrow.Cells["Description"].Value + "', DateStarted='" + myDgrow.Cells["DateStarted"].Value + "',TeamSize='" + myDgrow.Cells["TeamSize"].Value + "',Manager='" + myDgrow.Cells["Manager"].Value + "'";
cmd.Parameters.AddWithValue("@projectName1", myDgrow.Cells["ProjectName"].Value);
cmd.Parameters.AddWithValue("@Description1", myDgrow.Cells["Description"].Value);
cmd.Parameters.AddWithValue("@DateStarted1", myDgrow.Cells["DateStarted"].Value);
cmd.Parameters.AddWithValue("@TeamSize1", myDgrow.Cells["TeamSize"].Value);
cmd.Parameters.AddWithValue("@Manager1", myDgrow.Cells["Manager"].Value);
cmd.CommandText = myCmd;
cmd.ExecuteNonQuery();
dataGridView2.Update();
myCmd = string.Empty;
}
DataTable details = new DataTable();
SqlDataAdapter da = new SqlDataAdapter();
try
{
da.Update(details);
}
catch (Exception exceptionObj)
{
MessageBox.Show(exceptionObj.Message.ToString());
}
}