ICChip為Combobox.
自動檢測伺服器上的資料庫是否存在某表和某欄位，如果表不存在，先新建表，再在表下查詢某欄位，如果不存在，則新建欄位。

private void Database_Operation(ComboBox ICChip)
        {
            try
            {
                if (PubVar.SQL_Connection)//如果資料庫能開啟
                {
                    using (SqlConnection conn = new SqlConnection(PubVar.connStr))//
 
建立連線物件，並使用using釋放（關閉），連線用完後會被自動關閉
                    {
                        //if (conn.State == ConnectionState.Open) conn.Close();//如果開啟則先關閉
                        conn.Open(); // 開啟資料庫連線

                        string sql = "select 1 from INFORMATION_SCHEMA.TABLES where TABLE_NAME='" + ICChip.Text.Trim() + "
 
'";
                        SqlCommand command = new SqlCommand(sql, conn);//呼叫公共類中的ExceRead方法建立資料閱讀器
                        var Read = command.ExecuteScalar();

                        if (Read == null)//加個判斷,沒有則建立表
                        {
                            sql = "create table [" + ICChip.Text.Trim() + "
 
]([NO.] [int] identity(1,1))";//([NO.] [int] identity(1,1))";//建立表 //identity(1,1)自增ID
                            using (SqlConnection Conn = new SqlConnection(PubVar.connStr))
                            {
                                Conn.Open();
                                command = new SqlCommand(sql, Conn);
                                command.ExecuteNonQuery();
                            }

                        }
                        //判斷欄位是否存在
                        sql = "SELECT *FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = '" + ICChip.Text.Trim() + "' AND COLUMN_NAME = '新欄位'";
                        using (SqlConnection Conn = new SqlConnection(PubVar.connStr))
                        {
                            Conn.Open();
                            command = new SqlCommand(sql, Conn);
                            Read = command.ExecuteScalar();
                        }

                        if (Read == null)//如果沒有欄位則建立
                        {
                            sql = "ALTER TABLE [" + ICChip.Text.Trim() + "] ADD [新欄位] [text] null";//id int primary key IDENTITY(1,1) NOT NULL //建立欄位
                            using (SqlConnection Conn = new SqlConnection(PubVar.connStr))
                            {
                                Conn.Open();
                                command = new SqlCommand(sql, Conn);
                                command.ExecuteNonQuery();
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("錯誤資訊：" + ex.Message, "建立資料庫失敗！");
            }
        }