com.ExecuteNonQuery();附近语法错误问题

Question

StringBuilder SQL = new StringBuilder();
SQL.AppendLine("INSERT INTO M_USER");
SQL.AppendLine(" (USERN,PASSW)");
SQL.AppendLine(" VALUES('" + this.textBox1.Text.Trim() + "','" + this.textBox2.Text.Trim() + "'");

SqlConnection con = new SqlConnection();
con.ConnectionString = @"Data Source=MYWIN7\SQLEXPRESS;Initial Catalog=donetdb;Integrated Security=True";
con.Open();

SqlCommand com = new SqlCommand(SQL.ToString(), con);
com.ExecuteNonQuery();

con.Close();
MessageBox.Show("注册成功！");
this.Close();

在textBox2里输入7777777，运行到int i = com.ExecuteNonQuery()时，提示“7777777”附近有语法错误！望有心人帮忙指正。PS：在数据库里USERN,PASSW的数据类型都是varchar(16)。

Answer 1

SQL语句有问题：
insert into table values();少了後括号
SQL.AppendLine("INSERT INTO M_USER"); SQL.AppendLine(" (USERN,PASSW)"); SQL.AppendLine(" VALUES('" + this.textBox1.Text.Trim() + "','" + this.textBox2.Text.Trim() + "')");

Answer 2

少了一个最后的括号。
SQL.AppendLine(" VALUES('" + this.textBox1.Text.Trim() + "','" + this.textBox2.Text.Trim() + "')");

Answer 3

SQL.AppendLine(" VALUES('" + this.textBox1.Text.Trim() + "','" + this.textBox2.Text.Trim() + "')");