System.Data.OleDb.OleDbException 1つまたは複数のパラメータが必要

Question

私はVisual Studio Enterprise 2015 WPFを使用してプロジェクトを行い、データベースはmsアクセスファイルです なぜこのエラーが発生しているのかわかりませんここで

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.

私も

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; 

を試してみましたが、私のコード

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; 

です

しかし、まだ同じエラー例えば

私の接続文字列コマンド・テキスト行で

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

Answer 1

、：

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

ヤコブは、引用符でラップする必要がありません列名と表名：

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