I created a .h file for mysql connections. In my example file, I created an array of my class and made connection with the database for each subscript of the class object one by one. Then I checked if the connection in the previous subscripts are active or not, I found all the previous connection are disconnected.
I want to establish multiple connection with database at a time.
following code because i want to handle multiple connection and want to implement in my project
Code:
int newsockfd, pid;
socklen_t clilen;
struct sockaddr_in cli_addr;
[Code]...
My Questions
1. What these lines is doing
Code:
newsockfd = accept(m_sockfd, (struct sockaddr*) &cli_addr, &clilen);
Code:
close(m_sockfd);
Code:
close(newsockfd);
2. And why there is no create(), connect(), read(), write() methods for client
i want to write a server and a client as below:
The server(and not the clients) will connect to the clients and just send a message. The idea is to be able to connect at each client a different time.
e.g
every 10mins connect at client 1
every 2mins connect at client 2
every 1hour connect at client 3
and so on...
So how to implement this ? Should i create a new child process for each connection and what about the timing ? A pseudo code also will work.
I can't run my server immediately after closing it, it leaves some connection(zombies) leave open after the server is terminated. and i have to wait for some time to run the server again but immediately can't start the server
Here is my code
#include "NetManager.h"
NetManager::NetManager(){
}
NetManager::~NetManager() {
[Code] ....
I made a C++ Wrapper on top of ODBC.
I got a Connection, and a Statement class.
The Connection class holds the Database Connection ODBC Handle.
The Statement class holds the Statement Handle, there can be multiple per Connection. It is made and destroyed each time a query must be done on the DB.
Now I'm just wondering.
I have a multithreaded application.
Is keeping one Connection for one DB enough for the whole application? Where the different threads will make Statements based on that one Connection.Or is it better to keep a Connection per thread?
I have so far tried MySQL++, ODBC, SimpleDB, and the MySQL C++ Connector. All of them give me a FLOOD of errors in the output. Is there an easy way to connect?
View 7 Replies View RelatedThe resultset is always null and the connection is alive. The VS2013 debugger says that mysqlcppconn.dll has no debugging symbols. Tested the query on a mysql console and it worked fine, it returned 1.
CDatabase::CDatabase(CSettings* settings) {
settings = settings;
try {
Connection* con = get_driver_instance()->connect("", "", "");
con->setSchema("hyperbot");
cout << "Connected." << endl << endl;
[Code] .....
I also get these strange warnings on compile:
1>c:program files (x86)mysqlmysql connector c++ 1.1.3includecppconnsqlstring.h(38):
warning C4251: 'sql::SQLString::realStr' : class 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>'
needs to have dll-interface to be used by clients of class 'sql::SQLString'
[Code] ......
I am trying to write a C code with embedded MySQL with server and client options. I am trying to important a csv data file for MySQL server and client.
I saw on internet like: LOAD DATA LOCAL INFILE 'data.csv' INTO TABLE test FIELDS TERMINATED BY',' LINES TERMINTED BY' ';
But I think that line is for SQL workspace. How to write in C format?
Code:
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include "/usr/include/mysql/mysql.h"
MYSQL *mysql;
MYSQL_RES *results;
MYSQL_ROW record;
static char *server_options[] = { "data.csv", "--defaults-file=my.cnf" };
int num_elements = sizeof(server_options)/ sizeof(char *);
[Code] ......
I was created the mysql database in my Pc. This database connecting with vc++ code Using MySQL C++ Connection Example in Visual Studio. I done this work in single PC. It's working good. i viewed the table values using vc++ application.
But now want to connecting the database through lan connection. I refered the below link but i'm not clear.Step # 5 Grant access to remote IP address
For your reference, (I installed)
PC1 - visual studio 2003, mysql 5.6 for win32 & mysql connector (Ver : mysql-connector-c++-1.0.5-win32), OS : XP SP2, IP : 192.168.100.123
PC2 - mysql 5.6, OS: XP SP3, IP: 192,168,100.9
Table created in PC2, database name "test". server = 'localhost', user = 'root', passwd = "".
I like to connect PC1 & PC2 through Lan & access the table using vc++ code.
How can i view PC2's database table values in PC1?
So even though I have so many issues with linking libraries, I apparently became the go-to person for a fellow college friend of mine for a sql library. He's using the mysql connector/c++ and his team has had quite a few issues getting it set up. I've solved two out of three issues:
1st issue I solved was that they didn't know how to build boost, I just linked it and they were good to go.
2nd issue I solved was that they were missing libmysql.lib, I just installed the mysql server onto their computer and linked that up. 3rd issue is where I am now stumped at, as they get a compile error: LNK2001 unresolved external symbol: _get_driver_instance().
I don't understand when I'm only requesting a specific column on a unique row in MySQL that I'm being returned with data from all columns of that row.
My Select Statement - "select article from post where idpost=" + strIDpost + ";"
I should get:
|--- article -----|
"some article text"
Instead I get:
|-idpost-|-title-|---- article------|
1 title some article text
If I run the command directly to the database I get the results I'm looking for, but somehow while running the application, the program is managing to pull the entire row.
I'm using C# on a webform in Visual Studio '13. Here's my Code:
public static string GetConnectionString() {
string connStr = String.Format("server={0};user id={1}; password={2};" +
"database=dbname; pooling=false", "servername",
"dbUserID", "dbPassword");
[Code] .....
Basically I have a few tables in my Database.
So I have one table that is like so:
Item_ID, Name, Parent ID.
1 , jeff , 5
and another table like this:
Parent_ID, parent_Name
5,jackson
What I would like to happen, when I run my code is that I'll get the following
Item_ID, Name, parent_Name
1 , jeff , jackson
DataSet DS = new DataSet();
if (this.OpenConnection() == true) {
mySqlDataAdapter = new MySqlDataAdapter("select Item_ID, NAME, Parent_ID from table1, table2", connection);
mySqlDataAdapter.Fill(DS);
dataGridView1.DataSource = DS.Tables[0];
//close connection
this.CloseConnection();
}
So this spit out parent ID = 5.
I've not worked with Dataset before and I was just wondering what is the best approach? Can this be done via a SQL command or will I have to replace the value(5) with the string(jackson) using a large IF loop to search and replace.
I am currently developing a sync module using asp.net. I am getting data from an external database (mysql database) The problem is I am getting the error "Connection unexpectedly terminated" when filling the dataset.
Here's my code
string P_contact = "SELECT A.id, B.firstname, B.middlename, B.lastname FROM Accounts A, Contacts B WHERE A.id = B.id";
MySqlDataAdapter db_P_contact = new MySqlDataAdapter(P_contact, conn);
DataSet ds3 = new DataSet();
DataTable dt3 = new DataTable();
[Code] ....
I am getting the exception on this line of code:
db_P_contact.Fill(ds3, "P_contact");
i wanted to insert Decimal Values in MySQL database, but decimal values has precision and in C# there is not option to specify precision point, the last column is size which is integer.
MySqlParameter MySqlParameterCollection.Add(string parameter Name,MySqlDBTYPE dbType,int size);
Here my Code and i get error on last Line
MySqlCommand insert = new MySqlCommand("Insert into
Plan(Plan_ID,Plan_Title,Plan_rate,Plan_Length)
values(@p_id,@p_t,@p_r,@p_l);", con);
insert.Parameters.Add("@p_id", MySqlDbType.VarChar, 10).Value = p.p_id;
insert.Parameters.Add("@p_t", MySqlDbType.VarChar, 45).Value = p.p_title;
insert.Parameters.Add("@p_r", MySqlDbType.Decimal,10,2)=p.p_rate;
I just got this new project from my employer. He asked me to create a desktop application that could remotely access our sites database in cPanel.
View 4 Replies View Relatedim trying to get the row id created when inserting, ive tried ; SCOPE_IDENTITY(), get_last_identity() adding it to the end of my query string but get nothing back, it doesnt even add row to database. ive also tried adding a stored procedure but it doesnt even have the option in adding that when i right click to add it,(i thinks its because im using microsoft Access MySql)
public static Boolean checkoutOrder(string CustomerEmailId) {
DateTime CreatedDate = DateTime.Now;
DateTime ShippedDateDate = DateTime.Now;
string CustomerId = CustomerEmailId;
OleDbConnection myConnection = GetConnection();
[Code] .....
I wrote an application so I can manage the products for my e-commerce site. It uses MySQL 64 bit. Problem is some of my stores have in excess of 3 million products. The files that contain the data are all CSV. I parse the lines... format the data... write to table. On most of the stores which contain 10 - 60 thousand products it only takes max 3 min to write it all in. I have been running it on this one store for 6 hours now and it has barely made a dent. I know there are almost 3mil products in this one but it should be going much faster given what the speed was for the 60K stores. Is there a faster approach to handling a massive dump like this? I should also add that there are quite a few indexes. These indexes are there for ordering and fulltext search once the products have been activated on the site. I cannot create the table without the indexes and add them later since there is already preexisting data that is using the indexes.
View 2 Replies View Related i am student working on a project in c# to maintain the datas from a solar battery monitoring.i already imported the datas from the battery monnitoring and saved them in mysql database and retrived the data in c#.
i have problem in retriving the data in accordance with the date and time range selection.
what i am trying to do is there are more than 1000 datas in the table if i select two date and time the datas in the table should cross check these dates and show all the datas in the table in between those date&time
I'm using VS 2012. Installed MYSQL 5.6, C++ Connector 1.1.3. Created a sample table using mysql. Now i like to create a connect between mysql and MFC dialog. Using this, i was try to connect.
Server Explorer -> Data Connection -> Add Connections ->MYSQL Database -> Addconnection
To get the connection, i want to enter the connection settings like:
server host name = localhost, user name =root, password=
If I pressed any letter in the keyboard means add connection dialog was closed automatically.
How to connect mysql(localhost) with MFC Dialog?
How can i read particular record in a table quickly via VC++ from MYSQL?
I have a table like
Code:
Database name: test & Table name : Profilemaster
+-----+--------+
| PID | PNAME |
+-----+--------+
| 1 | APPLE1 |
| 2 | APPLE2 |
| 3 | APPLE3 |
| 4 | APPLE4 |
| 5 | APPLE5 |
+-----+--------+
My code is here, I was read all profilename from MYSQL database and load it to a combobox.
How can i read a particular record and store it to combobox?
Code:
void MainScreen::OnreadProfileName() {
// TODO: Add your control notification handler code here
CDatabase database;
CString SqlString;
CString sDsn;
CString pname;
[code].....
How can i execute this query and get the following result
SqlString = "SELECT PNAME FROM PROFILEMASTER WHERE PID =1;";
Code:
+-----+--------+
| PID | PNAME |
+-----+--------+
| 1 | APPLE1 |
+-----+--------+
I was looking at this code:
private void button1_Click(object sender, EventArgs e)
{
string input = textBox3.Text;
[Code].....
And how to rewrite the code so that it display the MySQL table data for a specific user I already have a string called username and that stores the username entered on the login form. I want the code to use the username string to search for the name and display that users info.
My table contents are: username
First name
Last name
Position
Employee Id
Airline
I want to develop an application which can host multiple views of explorer (window), where as each window is totally separate from others. So that I can have multiple desktop views through my single explorer. Any built in feature in .NET ?
View 11 Replies View Relatedhow to make subroutines and return multiple arrays.Before that, i wrote my program on matlab. could my program to be structured as following?
<header>
initial value of program;
subroutine1() {
calculating the first work;
return 2 or 3 arrays;
[code].....
I've been working on a function that works like a pipeline of a shell but receives a directory, go over it an search for every file to send it to a filter, something like this in bash "cat dir/* | cmd_1 | cmd_2 | ... | cmd_N", The only problem i have with the code is the redirection of the pipe descriptors.
Code:
int main(int argc, char* argv[]){
char** cmd;
int Number_cmd;
cmd = &(argv[2]); /*list of cmds*/
Number_cmd = argc-2; /*number of cmds*/
}
[code]....
The code is seems to work fine except when i run it with more than one command in example ("./filter DIR wc rev") in this case it returns
wc: standard input: Bad file descriptor
wc: -: Bad file descriptor
0 0 0
I'm using multiple C++ files in one project for the first time. Both have need to include a protected (#ifndef) header file. However, when I do that, I get a multiple definition error.
From what I found from research, adding the word inline before the function fixes the error. Is this the right way to do this, and why does it work? Should I make a habbit of just declaring any function that might be used in two .cpp files as inline?
I have written an SQL statement that would:
1) Count the number of rows in the table booking that are open and where the booking.postcode is "MK",
2) Take a note of the plot (in booking.plot_id), and then update the table plot.jobs with the value count.
For example running the SQL query when booking table has the following rows:
Would see the following highlighted values in plot.jobs being updated to 1:
I managed to resolve it with this code so far (note I am using Connector/Net):
public void RefreshPlot(){
string query =
"SELECT Count(*) AS count, plot_id FROM booking WHERE postcode='MK' AND status='open' GROUP BY plot_id";
var cmd = new MySqlCommand(query, _connection);
var da = new MySqlDataAdapter(cmd);
var dtCounts = new DataTable();
da.Fill(dtCounts);
[code]....
Currently, my code only checks for existing rows in the booking table and updates the plot table. However if the row gets deleted in the booking, then the changes are not reflected in the plot table.
Example: If we delete the row with plot.id=1 and plot.plot_id=4, then booking.plot_id should go back to being 0, if it was initially 1. At the moment, it doesn't. How would I update my SQL statement to better reflect this? In a sense, it should check for "non-existent" rows, i.e. the impact that the row plot.plot_id=4 & plot.id=1 has on booking.plot_id when deleted?