使用 sql 查询时出现“无效的列名”

有一个添加新组的表格（截图附在下面）。当您单击保存按钮时，此记录将保存到 tGroup 表中（成功）。保存后，应该从tGroup中取出这个组的id（主键），并转移到另一个表中（这就是sql查询出错的地方）。

void LoadIdGroup(string name)
        {
            adapter = new SqlDataAdapter("SELECT ID_Group from tGroups where sName="+name, connection);
            dtGroup = new DataTable();
            adapter.Fill(dtGroup);
            bsGroup = new BindingSource();
            bsGroup.DataSource = dtGroup;
        }
private void saveBtn_Click(object sender, EventArgs e)
    {
        connection.Open();
        SqlCommand commandInsert = new SqlCommand("INSERT INTO [tGroups]" +
            " VALUES(@Name, @Count)", connection);
        commandInsert.Parameters.AddWithValue("@Name", tbName.Text);
        commandInsert.Parameters.AddWithValue("@Count", tbCount.Text);
        commandInsert.ExecuteNonQuery();
        connection.Close();
        connection.Open();

        SqlCommand commandInsertRoutes = new SqlCommand("INSERT INTO [tGroupsRoutes]" +
        " VALUES (@ID_Group, @ID_Route)", connection);
         commandInsertRoutes.Parameters.AddWithValue("@ID_Route", Convert.ToInt32(cbRoutes.SelectedValue));
        LoadIdGroup(tbName.Text);
        commandInsertRoutes.Parameters.AddWithValue("@ID_Group", Convert.ToInt32(((DataRowView)this.bsGroup.Current).Row["ID_Group"]));
        commandInsertRoutes.ExecuteNonQuery();
        connection.Close();
        this.Dispose();
    }