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);

无论我做什么，都不插入参数。是什么给了什么？

Answer 1

不要在参数周围加上单引号，无论如何都暗示这些。

另外，尝试使用SqlCommand.CreateParameter：

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

尝试将'@Last'更改为@Last，同样适用于First ...