ExportDataToFile/Utility/PostgreSQLUtilityClass.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Data;
//using System.Data.Sql;
//using System.Data.SqlClient;
using System.Configuration;
using Npgsql;


namespace ManagementSystem.Utility
{
    public static class PostgreSQLUtility
    {
        #region 取得指定Table資料
        public static DataTable GetTable(string strTableName, int intTopCount, string[] strColumnList, string strWhere, string strOrderBy, NpgsqlConnection sqlConn)
        {
            DataSet dsData = new DataSet();
            try
            {
                string strColumns = "";
                string strCommand = "";
                foreach (string strColumn in strColumnList) //取得欄位陣列
                {
                    if (strColumns != "")
                    {
                        strColumns += "," + strColumn.Trim();
                    }
                    else
                    {
                        strColumns = strColumn;
                    }
                }

                if (intTopCount > 0)
                {
                    strCommand = string.Format("Select  {1} From \"{2}\" LIMIT {0}", intTopCount.ToString(), strColumns, strTableName);
                }
                else
                {
                    strCommand = string.Format("Select {0} From \"{1}\" ", strColumns, strTableName);
                }

                if (strWhere != "") //設定過濾條件
                {
                    strCommand += " Where " + strWhere;
                }

                if (strOrderBy != "")  //取得排序欄位
                {
                    strCommand += " Order By " + strOrderBy;
                }
                
                using (NpgsqlDataAdapter sqlAdapter = new NpgsqlDataAdapter(strCommand, sqlConn))
                {
                    if (sqlConn.State == ConnectionState.Closed)  //判斷連線狀態
                    {
                        sqlConn.Open();
                    }
                    sqlAdapter.Fill(dsData, "Result");
                }

                if (dsData.Tables.Count != 0)
                {
                    return dsData.Tables["Result"];
                }
                else
                {
                    return null;
                }
            }
            catch (Exception ex)
            {
                return null;
                throw ex;
            }
        }

        public static DataTable GetTable(string strTableName, int intTopCount, string[] strColumnList, string strWhere, NpgsqlConnection sqlConn)
        {
            return GetTable(strTableName, intTopCount, strColumnList, strWhere, "", sqlConn);
        }

        public static DataTable GetTable(string strTableName, int intTopCount, string[] strColumnList, NpgsqlConnection sqlConn)
        {
            return GetTable(strTableName, intTopCount, strColumnList, "", "", sqlConn);
        }

        public static DataTable GetTable(string strTableName, int intTopCount, NpgsqlConnection sqlConn)
        {
            return GetTable(strTableName, intTopCount, new string[] { "*" }, "", "", sqlConn);
        }

        public static DataTable GetTable(string strTableName, NpgsqlConnection sqlConn)
        {
            return GetTable(strTableName, 0, new string[] { "*" }, "", "", sqlConn);
        }

        #endregion

        #region MS-SQL命令相關程式集
        public static NpgsqlConnection GetConn(string strIP, string strDBName, string strID, string strPWD, string strPort)
        {
            try
            {
                string strConnectionString = "Host=" + strIP + ";Port="+ strPort + ";Database=" + strDBName + ";Username=" + strID + ";Password=" + strPWD;
                NpgsqlConnection sqlConn = new NpgsqlConnection(strConnectionString);
                sqlConn.ConnectionString = strConnectionString;
                sqlConn.Open();
                return sqlConn;
            }
            catch (Exception ex)
            {
                ErrorHandler.WriteErrorLog("PostgreSQLUtilityClass.cs", ex);
                return null;
            }
        }

        public static DataTable GetSQLResult(string strSQL, NpgsqlConnection sqlConn)
        {
            DataSet dsData = new DataSet();
            try
            {

                using (NpgsqlDataAdapter sqlAdapter = new NpgsqlDataAdapter(strSQL, sqlConn))
                {
                    if (sqlConn == null)
                        return null;
                    if (sqlConn.State == ConnectionState.Closed)  //判斷連線狀態
                    {
                        sqlConn.Open();
                    }
                    sqlAdapter.Fill(dsData, "Result");
                }
                if (dsData.Tables.Count != 0)
                {
                    return dsData.Tables["Result"];
                }
                else
                {
                    return null;
                }
            }
            catch (Exception ex)
            {
                return null;
                throw ex;
            }
        }

        public static bool IsExist(string strSQL, NpgsqlConnection sqlConn)
        {
            try
            {
                DataTable dtResult = GetSQLResult(strSQL, sqlConn);
                if (dtResult.Rows.Count > 0)
                { return true; }
                else
                { return false; }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        public static bool RunSQLNonReturn(string strSQL, NpgsqlConnection sqlConn)
        {
            try
            {
                NpgsqlCommand sqlCmd = new NpgsqlCommand(strSQL, sqlConn);
                if (sqlConn.State == ConnectionState.Closed)  //判斷連線狀態
                {
                    sqlConn.Open();
                }
                sqlCmd.ExecuteNonQuery();
                return true;
            }
            catch (Exception ex)
            {
                return false;
            }
        }

        public static string GetSQLCount(string strSQL, NpgsqlConnection sqlConn)
        {
            string strCount = "";
            DataTable dtTemp = GetSQLResult(strSQL, sqlConn);
            strCount = dtTemp.Rows.Count.ToString();

            //回傳查詢結果
            if (strCount == "")
            { return "0"; }
            else
            { return strCount; }
        }

        #endregion

    }
}