private bool ExistsTable(string TableName)
        {
            string sql = "select count(*) from sysobjects where name='" + TableName+"' and type='U'";
            SqlConnection cn = new SqlConnection("連接字符串");
            SqlCommand cmd = new SqlCommand(sql, cn);
            try
            {
                cn.Open();
                int cnt = Convert.ToInt32(cmd.ExecuteScalar());
                return (cnt == 0) ? false : true;
            }
            finally
            {
                cn.Close();
                cn.Dispose();
                cmd.Dispose();
            }
        }

------解决方案--------------------
C# code

            string sql = "create table tbname(col1 int primary key not null,col2 varchar(20) not null)";
            SqlConnection cn = new SqlConnection("連接字符串");
            SqlCommand cmd = new SqlCommand(sql, cn);
            try
            {
                cn.Open();
                cmd.ExecuteNonQuery();
                //不出異常，就已經成功
            }
            finally
            {
                cn.Close();
                cn.Dispose();
                cmd.Dispose();
                //失敗
            }