OleDbCommand，WHERE不关心

Question

使用Access表（CustomersTable）和两个字段（CustomerID，CustomerName）...字段＃2包含＆＃34; Zap＆＃34;：

command.CommandText = "SELECT  CustomerID, CompanyName   FROM CustomersTable   WHERE  CompanyName =  @p1";
command.Parameters.Add("@p1", OleDbType.VarChar).Value = "Zap";
reader = command.ExecuteReader();

工作正常。

将参数值更改为＆＃34; Za *＆＃34;一无所获。什么用于＆＃34;不关心＆＃34;？

Answer 1

因为＆＃34; Zap＆＃34;不等于＆＃34; Za＆＃34;

您需要使用Like运算符，如下所示： -

command.CommandText = "SELECT  CustomerID, CompanyName   FROM CustomersTable   WHERE  CompanyName LIKE @p1";
command.Parameters.Add("@p1", OleDbType.VarChar).Value = "%Za%";

Answer 2

我相信您想使用LIKE命令：

SELECT  CustomerID, CompanyName   FROM CustomersTable   WHERE  CompanyName LIKE  'Za%'