急！！！ C# 怎样操作 postgreSQl数据库

Question

这几天想用C#操作postgreSQl数据库，总是出问题，哪位达人有C#连接操作PostgreSQL的代码，能不能看一下！
email: [email protected]

Answer 1

我觉你的问题关键在于连接，只要连接成功基本上就没什么问题
至于连接去
www.connectionstrings.com
看看。

Answer 2

谢谢Knight94(愚翁)，不过我下了Npgsql和Core Labs PostgreSQLDirect (.NET) 
可不会用呀，请详细说说怎么连。

Answer 3

参看：
www.codeproject.com/cs/database/minosse.asp

Answer 4

哈 首先你要去下载一个postgresql的odbc驱动程序，然后用odbc连就可以了
string strCn="User Id=postgres;Password=password;Host=localhost;Database=database;
然后剩下的和别的数据库操作都一样了

Answer 5

我的一段代码
用的是odbc驱动using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
//
using System.Data.Odbc;
using System.IO;
using System.Drawing.Imaging;namespace ImageTest
{
    public partial class Form1 : Form
    {
        const string connectionString = "Driver={PostgreSQL};Server=192.168.100.100;Database=phpimage;Username=system1;Password=bl0il7;";        public Form1()
        {
            InitializeComponent();
        }        private void btnTest_Click(object sender, EventArgs e)
        {
            List<byte> lb = new List<byte>();            using (OdbcConnection thisConnection = new OdbcConnection(connectionString))
            {
                thisConnection.Open();
                string odbcCommand = "Select Count(*) from pg_largeobject where loid=59438";
                OdbcCommand thisCommand = new OdbcCommand(odbcCommand, thisConnection);
                int num = Convert.ToInt32(thisCommand.ExecuteScalar());                //string odbcCommand0 = "Select data From pg_largeobject Where loid=59438 and pageno=0";
                //string odbcCommand1 = "Select data From pg_largeobject Where loid=59438 and pageno=1";
                //
                odbcCommand = "Select data From pg_largeobject Where loid=59438 and pageno=";
                for (int i = 0; i < num; i++)
                {
                    thisCommand = new OdbcCommand(odbcCommand + i.ToString(), thisConnection);
                    ////using (OdbcDataReader thisReader = thisCommand.ExecuteReader())
                    ////{
                    ////    thisReader.Read();
                    ////    byte[] b = (byte[])thisReader[0];
                    ////    lb.AddRange(b);
                    ////}
                    byte[] b = (byte[])thisCommand.ExecuteScalar();
                    ////////////////////string b = (string)thisCommand.ExecuteScalar();
                    lb.AddRange(b);
                }
                byte[] resultBytes = new byte[lb.Count];
                lb.CopyTo(resultBytes);                FileStream fs = new FileStream("59438-new.jpg", FileMode.Create);
                BinaryWriter bw = new BinaryWriter(fs);
                bw.Write(resultBytes);
                bw.Close();
                fs.Close();
                
                MemoryStream ms = new MemoryStream(resultBytes);
                //ms.Write(resultBytes, 0, jpgSize);
                //Image image = new Bitmap(ms);
                Image image = Bitmap.FromStream(ms);
                ms.Close();
                pbDisplay.Image = image;
                                //pbLender.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
                ////这时流的Position应该是ms.Length-1
                //byte[] b = new byte[ms.Length];
                //ms.Position = 0;//你没这句,就真接读了,所以你的b中应该是清一色的0x00;
                //ms.Read(b, 0, (int)ms.Length);
                //ms.Close();            }            //SqlConnection conn = new SqlConnection();
            //conn.ConnectionString = "Data Source=localhost;Database=test;User Id=sa;Pwd=sa";
            //string strSql = "select FImage from test where id=1";
            //SqlCommand cmd = new SqlCommand(strSql, conn);
            //conn.Open();
            //SqlDataReader reader = cmd.ExecuteReader();
            //reader.Read();
            //MemoryStream ms = new MemoryStream((byte[])reader["FImage"]);            //Image image = Image.FromStream(ms, true);
            //reader.Close();
            //conn.Close();
            //ptbShow.Image = image; 
        }        private void btnTest2_Click(object sender, EventArgs e)
        {
            StringBuilder sbTest=new StringBuilder();
            using (OdbcConnection thisConnection = new OdbcConnection(connectionString))
            {
                thisConnection.Open();
                string odbcCommand0 = "Select data From pg_largeobject Where loid=59438 and pageno=0";
                string odbcCommand1 = "Select data From pg_largeobject Where loid=59438 and pageno=1";
                OdbcCommand thisCommand = new OdbcCommand(odbcCommand0, thisConnection);
                byte[] bTest=(byte[])thisCommand.ExecuteScalar();
                thisCommand = new OdbcCommand(odbcCommand1, thisConnection);
                string str = (string)thisCommand.ExecuteScalar();
                sbTest.Append(str);
                tbTest.Text = sbTest.ToString();
            }
        }
    }
}