OleDbDataAdapter .Fill() 方法给出了一个异常,说明没有为一个或多个必需参数给出值
OleDbDataAdapter .Fill() method gives an exception saying No value given for one or more required parameters
`OleDbConnection connect = new OleDbConnection(connectionString);
connect.Open();
string lastName = tBoxSurname.Text;
OleDbDataAdapter adapter = new OleDbDataAdapter(@"SELECT * FROM Players WHERE LastName=" + lastName, connect);
DataSet dataset = new DataSet();
adapter.Fill(dataset, "Players");
dataGridView1.DataSource = dataset;
dataGridView1.DataMember = "Players";
connect.Close();`
我不明白为什么它总是出现这个问题。我寻找不同的解决方案并尝试了很多,但我一直遇到同样的问题。如果有人可以请解释发生了什么,因为我最近开始学习数据库。
试试这个:
OleDbDataAdapter adapter = new OleDbDataAdapter();
OleDbCommand command = new OleDbCommand("SELECT * FROM Players WHERE LastName = ?", connect);
command.Parameters.Add("LastName", OleDbType.VarChar).Value = tBoxSurname.Text;
adapter.SelectCommand = command;
请 post 下次将您的代码作为片段而不是图片! :)
`OleDbConnection connect = new OleDbConnection(connectionString);
connect.Open();
string lastName = tBoxSurname.Text;
OleDbDataAdapter adapter = new OleDbDataAdapter(@"SELECT * FROM Players WHERE LastName=" + lastName, connect);
DataSet dataset = new DataSet();
adapter.Fill(dataset, "Players");
dataGridView1.DataSource = dataset;
dataGridView1.DataMember = "Players";
connect.Close();`
我不明白为什么它总是出现这个问题。我寻找不同的解决方案并尝试了很多,但我一直遇到同样的问题。如果有人可以请解释发生了什么,因为我最近开始学习数据库。
试试这个:
OleDbDataAdapter adapter = new OleDbDataAdapter();
OleDbCommand command = new OleDbCommand("SELECT * FROM Players WHERE LastName = ?", connect);
command.Parameters.Add("LastName", OleDbType.VarChar).Value = tBoxSurname.Text;
adapter.SelectCommand = command;
请 post 下次将您的代码作为片段而不是图片! :)