So, in university lecturers gave us a task to connect a postgresSql database with c# program. So far ir have thing looking like this.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.OleDb;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using System.Data.Common;
using Npgsql;
using NpgsqlTypes;
namespace ConsoleApplication4
{
class Program
{
static void Main(string[] args)
{
string postgresConStr = "Server=localhost;Port=5432;UserId=ricards;Password=muzika23;Database=prog4;";
NpgsqlConnection ncon = new NpgsqlConnection(postgresConStr);
NpgsqlCommand cmd = new NpgsqlCommand("SELECT * FROM persona", ncon);
ncon.Open();
NpgsqlDataReader dr = cmd.ExecuteReader();
DataTable dt = new DataTable();
dt.Columns.Add(new DataColumn("ID", typeof(int)));
dt.Columns.Add(new DataColumn("vards", typeof(string)));
dt.Columns.Add(new DataColumn("uzvards", typeof(string)));
dt.Columns.Add(new DataColumn("vecums", typeof(int)));
while (dr.Read())
{
DataRow row = dt.NewRow();
row["ID"] = dr["ID"];
row["vards"] = dr["vards"];
row["uzvards"] = dr["uzvards"];
row["vecums"] = dr["vecums"];
dt.Rows.Add(row);
}
ncon.Close();
dt.AcceptChanges();
int izvele;
do
{
Console.WriteLine("0 - Beigt darbu");
Console.WriteLine("1 - Apskatīt tabulas datus");
Console.WriteLine("2 - Pievienot tabulai datus");
Console.WriteLine("3 - Labot tabulas datus");
Console.WriteLine("4 - Dzēst tabuas datus");
Console.Write("Jūsu izvēle: ");
izvele = int.Parse(Console.ReadLine());
switch (izvele)
{
case 1:
PrintTable(dt);
break;
case 2:
DataRow drw = dt.NewRow();
Console.Write("Ievadiet studenta vārdu: ");
string vards = Console.ReadLine();
drw["vards"] = vards;
Console.Write("Ievadiet uzvārdu: ");
string uzvards = Console.ReadLine();
drw["uzvards"] = uzvards;
Console.Write("Ievadiet vecumu: ");
int vecums = int.Parse(Console.ReadLine());
drw["vecums"] = vecums;
dt.Rows.Add(drw);
ApplyToDb(dt, ncon);
break;
default:
break;
}
} while (izvele !=0);
}
static void PrintTable(DataTable dt)
{
foreach (DataColumn dc in dt.Columns)
{
Console.Write(dc.ColumnName + " ");
}
Console.WriteLine();
Console.WriteLine();
foreach (DataRow dr in dt.Rows)
{
for (int i = 0; i < dr.ItemArray.Length; i++)
{
Console.Write(dr[i] + "\t");
}
Console.WriteLine();
Console.WriteLine();
}
}
static void ApplyToDb(DataTable dt, NpgsqlConnection ncon)
{
NpgsqlCommand update = new NpgsqlCommand("UPDATE persona SET vards=?,uzvards=?, vecums=? WHERE ID =? ", ncon);
update.Parameters.Add(new NpgsqlParameter("@vardss", OleDbType.VarChar));
update.Parameters.Add(new NpgsqlParameter("@uzvards", OleDbType.VarChar));
update.Parameters.Add(new NpgsqlParameter("@vecums", OleDbType.VarChar));
update.Parameters.Add(new NpgsqlParameter("@ID", OleDbType.Integer));
NpgsqlCommand add = new NpgsqlCommand("INSERT INTO persona (vards, uzvards, vecums) VALUES(@vards, @uzvards, @vecums)", ncon);
add.Parameters.Add(new NpgsqlParameter("@vards", OleDbType.VarChar));
add.Parameters.Add(new NpgsqlParameter("@uzvards", OleDbType.VarChar));
add.Parameters.Add(new NpgsqlParameter("@vecums", OleDbType.VarChar));
foreach (DataRow dro in dt.GetChanges().Rows)
{
if (dro.RowState == DataRowState.Added)
{
add.Parameters[0].Value = dro[1];
add.Parameters[1].Value = dro[2];
add.Parameters[2].Value = dro[3];
ncon.Open();
add.ExecuteNonQuery();
ncon.Close();
}
if (dro.RowState == DataRowState.Modified)
{
update.Parameters[0].Value = dro[1];
update.Parameters[1].Value = dro[2];
update.Parameters[2].Value = dro[3];
update.Parameters[3].Value = dro[0];
ncon.Open();
update.ExecuteNonQuery();
ncon.Close();
}
}
}
}
Im sure that code is not the problem, i have checked connectionStrings paths and they all match to postgres (host,database,user and so on). The thing i want to know is, do i have to put that postgres database in c# programs debug folder or what? Professor did not mention a thing about it? And, how do i even find that database, i have searched whole Postgres folder, but cant seem to find where them databases are hidden.
Please help me out.
Thanks
EDIT
update.Parameters.Add(new NpgsqlParameter("@vardss", OleDbType.VarChar));
Do i need to change the OleDbType to postgres type? How to do it? (This part - OleDbType.VarChar)
There is not postgres compact edition.
You need a postgres server, you can download it from postgres site , or if you have some hyper-v, vmware, virtualbox app, you can download one virtual appliance from turnkey .
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