与添加查询参数的问题

Question

代码：

com.CommandText = "select username, pass from Employees where lastName like '@Last' and firstName like '@First'"; 
com.Parameters.AddWithValue("@Last", lastName); // lastName is a method argument 

SqlParameter param = new SqlParameter(); 
param.ParameterName = "@First"; 
param.Value = firstName; 
com.Parameters.Add(param); 

不管我做什么，参数没有插入。是什么赋予了？

Answer 1

不要把单引号放在你的参数中，这些都是隐含的。

而且，尝试使用SqlCommand.CreateParameter还有：

com.CommandText = "select username, pass from Employees where lastName like @Last and firstName like @First"; 
com.Parameters.AddWithValue("@Last", lastName); // lastName is a method argument 

SqlParameter param = com.CreateParameter(); 
param.ParameterName = "@First"; 
param.Value = firstName; 
com.Parameters.Add(param); 

Answer 2

试图改变 '@Last' 到@Last，对于第一次同样的事情...