//Update data in database
public bool Update(ContactClass c)
{
// Connect to Postgres
NpgsqlConnection conn = new NpgsqlConnection(myConnectionString);
bool querySuccess = false;
try
{
//Update contact inside the database
string query = "UPDATE contacts SET lastName=@lastName, " +
"firstName=@firstName, phoneNumber=@phoneNumber, address=@address WHERE " +
"contactID=@contactID";
//Create command using query string and connection
NpgsqlCommand cmd = new NpgsqlCommand(query, conn);
cmd.Parameters.AddWithValue("@lastName", c.LastName);
cmd.Parameters.AddWithValue("@firstName", c.FirstName);
cmd.Parameters.AddWithValue("@phoneNumber", c.PhoneNumber);
cmd.Parameters.AddWithValue("@address", c.Address);
cmd.Parameters.AddWithValue("@contactID", c.ContactID);
conn.Open();
int rows = cmd.ExecuteNonQuery();
//If the query runs successfully, the value of rows will be greater than 0, else it will be 0
if (rows > 0)
{
querySuccess = true;
}
else
{
querySuccess = false;
}
}
catch (Exception e)
{
}
finally
{
conn.Close();
}
return(querySuccess);
}
//Insert data into database
public bool Insert(ContactClass c)
{
// Connect to Postgres
NpgsqlConnection conn = new NpgsqlConnection(myConnectionString);
bool querySuccess = false;
try
{
//Insert new contact into the database
string query = "INSERT INTO contacts (lastName, firstName, phoneNumber, address) VALUES(@lastName, @firstName, @phoneNumber, @address)";
//Create command using query string and connection
NpgsqlCommand cmd = new NpgsqlCommand(query, conn);
cmd.Parameters.AddWithValue("@lastName", c.LastName);
cmd.Parameters.AddWithValue("@firstName", c.FirstName);
cmd.Parameters.AddWithValue("@phoneNumber", c.PhoneNumber);
cmd.Parameters.AddWithValue("@address", c.Address);
conn.Open();
int rows = cmd.ExecuteNonQuery();
//If the query runs successfully, the value of rows will be greater than 0, else it will be 0
if (rows > 0)
{
querySuccess = true;
}
else
{
querySuccess = false;
}
}
catch (Exception e)
{
}
finally
{
conn.Close();
}
return(querySuccess);
}
//Delete data in database
public bool Delete(ContactClass c)
{
// Connect to Postgres
NpgsqlConnection conn = new NpgsqlConnection(myConnectionString);
bool querySuccess = false;
try
{
//Update contact inside the database
string query = "DELETE FROM contacts WHERE contactID=@contactID";
//Create command using query string and connection
NpgsqlCommand cmd = new NpgsqlCommand(query, conn);
cmd.Parameters.AddWithValue("@contactID", c.ContactID);
conn.Open();
int rows = cmd.ExecuteNonQuery();
//If the query runs successfully, the value of rows will be greater than 0, else it will be 0
if (rows > 0)
{
querySuccess = true;
}
else
{
querySuccess = false;
}
}
catch (Exception e)
{
}
finally
{
conn.Close();
}
return(querySuccess);
}