为什么读入数据库的是“SQL2”，而不是填入box里的值
using (SqlConnection str1 = new SqlConnection("Data Source=(local);database=NewData;uid=sa;pwd=xitong"))
{ str1.Open();
string SQL2 = this.tbBrand.Text;

SqlCommand com = new SqlCommand();
com.CommandText="insert into NVR(Brand) values ('SQL2')";

com.Connection=str1;
com.ExecuteNonQuery();
str1.Close();
}

[解决办法]
com.CommandText="insert into NVR(Brand) values ('"+SQL2+"')";
[解决办法]
com.CommandText="insert into NVR(Brand) values ('"+SQL2+"')";
SQL2是变量，你当做字符串的值穿进去了