C# 将值从MySQL DB加载到datagrid视图中的特定列
我想从数据库中提取数据。我只需要显示前三列(0,1,2),而不是全部。我怎么能这么做C# 将值从MySQL DB加载到datagrid视图中的特定列,c#,mysql,database,winforms,datagrid,C#,Mysql,Database,Winforms,Datagrid,我想从数据库中提取数据。我只需要显示前三列(0,1,2),而不是全部。我怎么能这么做 > string selectQuery = "select command line goes here where.... offerMadeBy='"+cbox1.Text.ToString()+"';"; > MySqlConnection sqlCOnnect = new MySqlConnection(RootDBConnection.myConn
> string selectQuery = "select command line goes here where.... offerMadeBy='"+cbox1.Text.ToString()+"';";
> MySqlConnection sqlCOnnect = new MySqlConnection(RootDBConnection.myConnection);
> MySqlCommand sqlCmd = new MySqlCommand(selectQuery,sqlCOnnect);
> MySqlDataAdapter sqlAdapter;
> try {
> sqlAdapter = new MySqlDataAdapter();
> sqlAdapter.SelectCommand = sqlCmd;
>
> DataTable dbset = new DataTable();
> sqlAdapter.Fill(dbset);
> BindingSource bindSource = new BindingSource();
>
> _dataGridView.DataSource = null;
> bindSource.DataSource = dbset;
> _dataGridView.DataSource = bindSource;
> sqlAdapter.Update(dbset);
>
>
> if (sqlCOnnect.State == ConnectionState.Open) {
> sqlCOnnect.Close();
> }
> }catch(MySqlException ex){
> MessageBox.Show("Can't load data from DB.\nReason:"+ex.Message);
> }
您可以从数据库中选择所需的字段。此外,您必须打开与SQL的连接,最后使用参数,例如:
string selectQuery = "select field1,field2,field3 from mytable where offerMadeBy=@param";
MySqlConnection sqlCOnnect = new MySqlConnection(RootDBConnection.myConnection);
MySqlCommand sqlCmd = new MySqlCommand(selectQuery,sqlCOnnect);
sqlCmd.Parameters.AddWithValue("@param", cbox1.Text.ToString());
try {
sqlCOnnect.Open()
using (sqlCOnnect)
{
....
}
}
你不能只选择sql中需要的列(
selectQuery
)?好吧,作为提示。这很明显,就像从DB到Combobox获取值一样。好的,你能解释一下为什么我要这样写“@”和Parameters.AddWIthValue吗?这只是防止SQL注入?是的,最重要的好处是防止注入,但是使用参数优化了c#part的查询执行