System.Data.OleDb.OleDbException 需要一个或多个参数

Question

我使用 Visual Studio Enterprise 2015 WPF 来做我的项目，我的数据库是一个 ms 访问文件我不确定为什么会出现此错误有人可以

An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in System.Data.dll Additional information: No value given for one or more required parameters.

这是我的代码

OleDbConnection con = new OleDbConnection();
con.ConnectionString = ConfigurationManager.ConnectionStrings["Connection"].ToString();
con.Open();
OleDbCommand cmd = new OleDbCommand();
cmd.CommandText = "select `Name1`,`ID` from `Employee` WHERE `Name1` = Jacob ";
cmd.Connection = con;
OleDbDataReader rd = cmd.ExecuteReader();
grid1.ItemsSource = rd;

我也试过了

OleDbConnection con = new OleDbConnection();
con.ConnectionString = ConfigurationManager.ConnectionStrings["Connection"].ToString();
con.Open();
OleDbCommand cmd = new OleDbCommand();
cmd.CommandText = "select Name1,ID from [Employee] WHERE Name1 = Jacob ";
cmd.Connection = con;
OleDbDataReader rd = cmd.ExecuteReader();
grid1.ItemsSource = rd;


OleDbConnection con = new OleDbConnection();
con.ConnectionString = ConfigurationManager.ConnectionStrings["Connection"].ToString();
con.Open();
OleDbCommand cmd = new OleDbCommand();
cmd.CommandText = "select * from [Employee] WHERE Name1 = Jacob ";
cmd.Connection = con;
OleDbDataReader rd = cmd.ExecuteReader();
grid1.ItemsSource = rd;

但还是一样的错误

我的连接字符串

<connectionStrings>
<add name="Connection" connectionString="Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\wpfdb.accdb;Persist Security Info=False;"/>

Answer 1

在您的命令文本行中，例如：

> cmd.CommandText = "select `Name1`,`ID` from `Employee` WHERE `Name1` =
> Jacob ";

Jacob 需要用引号引起来，而不是列和 table 名称：

cmd.CommandText = "select * Employee WHERE Name1 = 'Jacob' ";

System.Data.OleDb.OleDbException 需要一个或多个参数

System.Data.OleDb.OleDbException Require one or more parameters

c#

mysql

sql

database

oledb