I have a problem I need to solve, but not know how exactly. I have a WinForms application (C#) which connects to an online MySQL server - no problem there. In this application I have an option to make database backups (basically I dump this database to a local file on a computer).
I would like to locally "open" this backup on client's computer (to check some old data) - I don't want to make database restore on my server, because database must still be in use for other users. I want to make clean install of MySQL on a local computer and connect to it trough localhost (like I do for testing ), but I do not have physical access to that computer. I can send MySQL installer to my client, but how to go about automatically creating user with password and database from my dump file?
I know how to create a new database if it doesn't exist, but how to do it if it's clean install of MySQL server - no user and password yet.
string connStr = "server=localhost;user=root;port=3306;password=????;";
using (var conn = new MySqlConnection(connStr))
using (var cmd = conn.CreateCommand())
{
conn.Open();
cmd.CommandText = "CREATE DATABASE IF NOT EXISTS `hello`;";
cmd.ExecuteNonQuery();
}
Any help and direction is appreciated.
Regards!
I don't know whether I understand your problem. However,if you install a new Mysql，you can use root user through no database.
Anyway, one thing you need to know,Connect database must has user and password for mysql or sqlserver.
You may need to be more concise description of your problem.
Related
After a few years, I have returned to writing in C# and I am really struggling here - I would like to have my app to have a local SQL database. I have added Service-based database and "Database1.mdf" was added to my project. I created a table and added some data just to see if it is working but I cannot connect to it. I tried numerous connection strings with no success (Server not accessible).
Do I need to run something else in the background? I thought that I might have a local database and with .NET client I can access it, and I hoped it would work whenever I bring my application (also not requiring any SQL server running). Is that wrong?
If you don't require any SQL server, take a look at SQLite. This is lite SQL database engine. Database is just one file. C# has a great library to SQLite on NuGet: https://www.nuget.org/profiles/mistachkin
SQLite is widely used, event in Android (as a native db engine).
here is what i use to connect. it appears as a Data Connection in Server Explorer.
string con2 = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=" + Application.StartupPath + "\\jobfile_2017.mdf;Integrated Security=True;Connect Timeout=30";
when i first started working with these, i used this source 1
it works on PC's that i have nothing installed (not even office) but as i said i'd be interested to know of any shortcomings of this method
I experiencing same problem and decided to move mdf file to static c:\db directory. Connection string was changed to incorporate new file location (AttachDbFile).
But AttachDbFile has some issues also (by some reason one table in db is inaccesible and error is access denied).
So I decided to move to Sqlite. LocalDb has many issues to work with. I read good note to resolve problem: in command line stop/remove/start name of instance. But it nuissance.
Wish you good luck to work with these db files.
I need your help.. maybe it's the small task which I am not able to solve but I don't know how to search that on any search engine
I am using an .mdf file (vs 2103) in my WPF login register desktop application.. Everything is working fine, no compilation errors. I inserted some data into the .mdf file by using query in Visual Studio and then try to login through application and it's working fine. Moreover I am also able to register, i.e., insert into .mdf file from the register option of application if I use the "absolute path" of the .mdf file. Problem begins when I try to insert into .mdf file using a "relative path"... it doesn't insert data into the .mdf....I don't know why.
(this absolute path is not working. I have .mdf file in the database folder)
//connection string
connetionString = #"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\Database\Database1.mdf;Integrated Security=True";
//code
SqlCommand sqlCmd;
string sql = null;
SqlConnection sqlCnn = new SqlConnection(connetionString);
try
{
sqlCnn.Open();
sql = "insert into [NewTable] ( Name , Password ) values ('ABC' , '12345')";
sqlCmd = new SqlCommand(sql, sqlCnn);
sqlCmd.ExecuteNonQuery();
sqlCnn.Close();
MessageBox.Show("You have Been Registered");
}
catch (Exception ex)
{
MessageBox.Show("" + ex);
}
It shows the message "You have Been Registered"
but is not visible in .mdf file...
I want to ask..why is it behaving like this....and I want to use the relative path as we cant judge the client system absolute path...what mistake I am doing? how to handle this (i guess self made) issue?
The whole AttachDbFileName= approach is flawed - at best! When running your app in Visual Studio, it will be copying around the .mdf file (from your App_Data directory to the output directory - typically .\bin\debug - where you app runs) and most likely, your INSERT works just fine - but you're just looking at the wrong .mdf file in the end!
If you want to stick with this approach, then try putting a breakpoint on the myConnection.Close() call - and then inspect the .mdf file with SQL Server Mgmt Studio Express - I'm almost certain your data is there.
The real solution in my opinion would be to
install SQL Server Express (and you've already done that anyway)
install SQL Server Management Studio Express
create your database in SSMS Express, give it a logical name (e.g. MyDatabase)
connect to it using its logical database name (given when you create it on the server) - and don't mess around with physical database files and user instances. In that case, your connection string would be something like:
Data Source=.\\SQLEXPRESS;Database=MyDatabase;Integrated Security=True
and everything else is exactly the same as before...
Also see Aaron Bertrand excellent blog article Bad habits to kick: Using AttachDbFileName for more in depth explanations and tips
I am trying to establish connection between my application in C# and MySQL. I have downloaded .NET connector from MySql website.
I have installed MySQL server with TYPO3 winstaller, and it is running properly.
Here is my code:
MySqlConnection con = new MySqlConnection("Server=localhost:8501;Database=drogy;Uid=root;Pwd=;");
con.Open();
It says that: Unable to connect to any of the specified MySQL hosts.
In PHPMyAdmin I see host as localhost:8501. I am sure that user root has password set to NO and I am also pretty sure about the database name. How can I do this please? Thank you
you should not mention the password if maybe its should be empty means use the ' ' single quotes in you code.
And you should remove the ; in after the password like ot;Pwd=;"); you should change like ot;Pwd=");
if your not add the connector, first of all you should must add the MySQL Connector.
sample code:
"server=localhost:portno; user id=yourusername; password=yourpassword; database=yourdatabasename"
update:1
All had happend after moving database files to new location and after updating mysql server. All tables with InnoDB engine disappeared from my database. I was trying to recreate them, but mysql told me 1146: Table 'xxx' doesn't exist all the time until I had recreated my database and restarted mysql service.
I think there's a need to read about InnoDB table binaries.
click here : 1
*Pwd=;"*Required your database password
In the password field give your password and try it.. it will work
I'm very new to SQL and made a small program where a user can input some data, click submit and the data is then stored in a table in the database.
I know want to move the application onto a friends computer, which i'm assuming has no SQL software installed, what would be the easiest way to do this, when obviously the connection string is unique to my computer and the database is stored on my computer.
You will have to install SQL Server on their machine first and foremost. Once this is done, you can obtain a relevant connection string. Note, for the 'Server name' part of the connection string, if you are using SQL Express, instead of using 'localhost', or the name of the server instance (i.e. 'MyMachine'), you would use 'localhost\SQLEXPRESS'/'MyMachine\SQLEXPRESS'.
After setting up the SQL Server instance on the new machine, to copy the required database, first detach the database to avoid any corruption. Now you are free to merely copy the file from your machine to theirs and go through the usual attachment process using SQL Server Management Studio (SQLMS).
I hope this helps.
You can use SQL CE or other file databases. On this way you need to install SQL CE(you can include SQl CE installer into your program installer) on target computer and after that you can easy copy db-file from you computer to target computer.
Also, you can use relative path to db-file from your exe file instead of fixed connection string:
string dbDirPath=Path.Combine(AppDomain.CurrentDomain.BaseDirectory,"DB" );
private const string CONN_STR_TEMPLATE = "Data Source={0};Persist Security Info=False;";
string dbFilePath = Path.Combine(dbDirPath, "my.sdf");
_connStr =String.Format(CONN_STR_TEMPLATE,dbFilePath);
You cannot simply copy your database since SQL Server database is NOT a standalone database as SQL Compact edition/MS Access.
You may configure your router to remote access SQL Server instance over the Internet by forwarding the port
Accessing SQL Server Instance through NAT
I'm making an app that will be installed and run on multiple computers, my target is to make an empty local database file that is installed with the app and when user uses the app his database to be filled with the data from the app .
can you provide me with the following examples :
what do I need to do so my app can connect to its local database
how to execute a query with variables from the app for example how would you add to the database the following thing
String abc = "ABC";
String BBB = "Something longer than abc";
and etc
Edit ::
I am using a "local database" created from " add > new item > Local database" so how would i connect to that ? Sorry for the dumb question .. i have never used databases in .net
Depending on the needs you could also consider Sql CE. I'm sure that if you specified the database you're thinking of using, or your requirements if you're usure you would get proper and real examples of connection strings etc.
Edit: Here's code for SqlCe / Sql Compact
public void ConnectListAndSaveSQLCompactExample()
{
// Create a connection to the file datafile.sdf in the program folder
string dbfile = new System.IO.FileInfo(System.Reflection.Assembly.GetExecutingAssembly().Location).DirectoryName + "\\datafile.sdf";
SqlCeConnection connection = new SqlCeConnection("datasource=" + dbfile);
// Read all rows from the table test_table into a dataset (note, the adapter automatically opens the connection)
SqlCeDataAdapter adapter = new SqlCeDataAdapter("select * from test_table", connection);
DataSet data = new DataSet();
adapter.Fill(data);
// Add a row to the test_table (assume that table consists of a text column)
data.Tables[0].Rows.Add(new object[] { "New row added by code" });
// Save data back to the databasefile
adapter.Update(data);
// Close
connection.Close();
}
Remember to add a reference to System.Data.SqlServerCe
I'm not seeing anybody suggesting SQL Compact; it's similar to SQLite in that it doesn't require installation and tailors to the low-end database. It grew out of SQL Mobile and as such has a small footprint and limited feature-set, but if you're familiar with Microsoft's SQL offerings it should have some familiarity.
SQL Express is another option, but be aware that it requires a standalone installation and is a bit beefier than you might need for an applciation's local cache. That said it's also quite a bit more powerful than SQL Compact or SQLite.
Seems like you're:
-Making a C# app that will be installed and run on multiple
computers
-That needs a local database (I'm assuming an RDBMS)
-You need to generate a blank database at installation
-You then need to be able to connect to the database and populate it when
the app runs.
In general, it seems that you need to read up on using a small database engine for applications. I'd start by checking out SQLite, especially if you need multi-OS capability (eg., your C# program will run on Microsoft's .NET Framework and Novell's Mono). There are C# wrappers for accessing the SQLite database.
I believe this question is about the "Local Database" item template in Visual Studio:
What are you considering as a database? From what little you've provided in your question, I'd suggest SQLite.
You can get sample code from their site Sqlite.NET
Not sure I fully understand what you're asking but Sqlite is a good option for lightweight, locally deployed database persistence. Have a look here:
http://www.sqlite.org/
and here for an ADO.NET provider..
http://sqlite.phxsoftware.com/
For 1)
The easiest way to provide this functionality is through SQL Server Express User Instances. SQL Server Express is free, so your user does not have to pay additional license for SQL Server, and the User Instance is file-based, which suits your requirement.
For 2)
This is a big topic. You may want to go through some of the tutorials from Microsoft to get the feeling of how to connect to DB, etc.