System.Data.OleDb.OleDbException需要一個或多個參數

Question

我'使用Visual Studio Enterprise 2015 WPF做我的項目，我的數據庫是一個ms訪問文件 我不知道爲什麼我有這個錯誤可以有人

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.

這裏是我的代碼

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; 

我也曾嘗試

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; 

但還是同樣的錯誤

我的連接字符串

<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，例如：

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

雅各需要被包裹在引號，而不是專欄和表名：

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