Develop Reference

How to convert Azure DB URL to localhost DB URL?

I've got an Azure SQL Server database that I'm connecting to via JDBC, but want to connect instead to my SQL Server "localhost". In SSMS, I connect to localhost without needing a password. So, do I still need to enter a password in Java?
I have a code like this :
String connectionUrl =
"jdbc:sqlserver://etcetc.database.windows.net:1433;"
+ "database=med;"
+ "user=windersan#salemimed;"
+ "password=********;"
+ "encrypt=true;"
+ "trustServerCertificate=false;"
// + "hostNameInCertificate=*.database.windows.net;"
+ "loginTimeout=30;";
How do I change this to connect instead to localhost?

Just replace the etcetc.database.windows.net by localhost and replace the port number 1433 by the number that you are using.
I have used SQLServerDataSource class to make the work easier. You can also create a string URL and set it in the DriverManger.getConnection().
Try with this code :
SQLServerDataSource dataSource = new SQLServerDataSource();
dataSource.setUser("windersan#salemimed");
dataSource.setPassword("********");
dataSource.setServerName("localhost");
// set the port number of your system below.
dataSource.setPortNumber(1433);
dataSource.setDatabaseName("med");
dataSource.setEncrypt(true);
dataSource.setHostNameInCertificate("*.database.windows.net");
dataSource.setTrustServerCertificate(false);
Connection connection = dataSource.getConnection();
Please refer to this links down below for more info.
Microsoft Docs - ISQLServerDataSource Interface - This contains the list of methods that you can use to set the various properties in the datasource.
Microsoft Docs - How to work with the connection - This contains examples of the possible ways to connect to a SQL Server database.

the first line of your concatenated string contains the url etcetc.database.windows.net:1433 this is the location of the database server, and the bit you should change.
Also, it might be worth doing a google search on connecting to SqlServer with JDBC to see if there are any examples out there.

Java connect with JDBC to Postgres - SQLException

Iam tryig to connect to a Postgres Database. Iam really new to that and have read a post in the forum. But I didn't manage it.
public void connect() {
//Connection con = null;
try {
Class.forName("org.postgresql.Driver");
Properties props = new Properties();
props.setProperty("user", user);
props.setProperty("password", password);
props.setProperty("ssl","true");
Connection conn = DriverManager.getConnection(url, props);
//String url = "jdbc:postgresql://localhost/test?user=fred&password=secret&ssl=true";
//Connection conn = DriverManager.getConnection(url);
System.out.println("Erfolgreich verbunden!");
}
catch (Exception e){
e.printStackTrace();
System.err.println(e.getClass().getName()+": "+e.getMessage());
System.exit(0);
}
}
EDIT:
I updated my Code.
The database is deployed to heroku.
It throws the error:
java.sql.SQLException: No suitable driver found for jdbc:postgres://vuqmbekwlgohkw:******
at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:702)
at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:189)
at com.company.Database.connect(Database.java:20) p
at com.company.Main.start(Main.java:16)
at com.company.Main.main(Main.java:25)
java.sql.SQLException: No suitable driver found for jdbc:postgres://vuqmbekwlgohkw:***************

I believe that your problem is that your connection URL is malformed.
When DriverManager.getConnection throws SQLException, the message includes the exact url value passed to the function. In your case, that looks like jdbc:postgres://vuqmbekwlgohkw:******.
But obviously that is not the URL you are using. You have replaced part of the URL with asterisks. That suggests that you think the format of the URL is:
jdbc:postgres://username:password#host:port/dbname
which seems to be what Heroku provides in the DATABASE_URL environment variable. You are using asterisks to prevent us from seeing the password.
However, it looks like the PostgreSQL JDBC driver does not accept URLs in this format. When I tried, I also got the "No suitable driver" error. According to the documentation, the format of the URL is:
jdbc:postgres://host:port/database
Some parts are optional, but the driver does not appear to support putting the user name or password in the URL.
I was able to connect to an AWS PostgreSQL instance by using the URL format described in the documentation and using the connection properties to set the user name and password.

You said you are new so I'm gonna start with the painfully obvious, do you have the driver on your classpath?
it's a jar you add to your project that you can download from https://jdbc.postgresql.org/
Otherwise I have an example of the url that worked for me, except I was not exactly using jdbc, it was a spring-boot project:
jdbc:postgresql://ec2-174-99-88-88.compute-1.amazonaws.com:5432/asdfasdfsadf?sslmode=require
There is no port number in your commented URL and not all parameters might be supported, like Willis pointed out.

No suitable driver found for jdbc:sqlserver:

I know this has been asked a hundred times and I think I have read all the posts and tried every variation of the solutions. I'm using NetBeans and new to it. I'm sure I'm just missing some small step because it seems like its just not seeing the driver that I added to the library. This is the first time I have tried to connect to a database so please be gentle.
try
{
String host = "jdbc:sqlserver://Server:1433;Database";
String uName = "User";
String uPass = "Password";
Connection con = DriverManager.getConnection(host,uName,uPass);
System.out.println("Your are connected to SQLServer 2014");
}
catch (SQLException err)
{
System.out.println(err.getMessage());
}

You forgot to register the jdbc driver class.
Call
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
before calling Connection con = DriverManager.getConnection(host,uName,uPass);.
It will resolve the issue.
UPDATE
In documentation for new jdbc drivers it is declared that this step is not necessary. But in practical work, I have found that this step is required even for new drivers, otherwise you will get "No suitable driver found" error. This error occurs sometimes, for example it does not occur when you are making and running a console jar-application, but occurs when you have created and deployed a web-application.
So, I advise to register the jdbc driver class before getting the database connection via DriverManager.getConnection() call.

Connecting to mySQL Database with Java

In my program I am trying to connect to a mySQL database. This program is written in Java.
I am trying to connect to my database with this code here (? is a place holder b/c I dont know what does there.)
Connection conn = DriverManager.getConnection("jdbc:sqlite:*?*");
I need someone to help me replace the ? to connect to my database. I know the IP (Just call it ***.***.*** for security reasons, the port which is 3306 and the database is called devicede_Test).
Please help me replace the ? with the correct string with the info above, thanks!

Try this
Connection conn = DriverManager.getConnection("jdbc:mysql://***.***.***:3306/dbname");

Try this:
String url = "jdbc:mysql://localhost:3306/mysql";
Connection con = DriverManager.getConnection(url,"root", "");

SQLIte is not the right driver here. Use:
Connection conn = DriverManager.getConnection("jdbc:mysql://**.***.***.***/devicede_Test", user, pass);

The JDBC URL format for MySQL Connector/J is as follows, with items in square brackets ([, ]) being optional:
jdbc:mysql://[host][,failoverhost...][:port]/[database] »
[?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]...
Here is a sample connection URL:
jdbc:mysql://localhost:3306/sakila?profileSQL=true
Source : http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-configuration-properties.html

Java: Trouble connecting to MySQL

I'm writing a desktop java app on that I want to connect to a MySQL database on a server. Here is the code to do that:
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
private static Connection getDBConnection() throws SQLException, InstantiationException, IllegalAccessException, ClassNotFoundException {
String username = "myUserName";
String password = "myPassWord";
String url = "jdbc:mysql://www.domainName.com:3306/databaseName";
Class.forName("com.mysql.jdbc.Driver");
System.out.println("Connecting to database...");
//hangs here
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
When I run this, it hangs on the DriverManager.getConnection() call. Why does this happen? Is my URL malformed?
(I'm not getting any error messages, but the program doesn't respond as if in an infinite loop. I haven't waited longer than 90 seconds to see if the connection will ever be established.)
Also, what is the purpose of the Class.forName() call? How does it work?
I am almost entirely certain that the username and password are correct. (I just used userName and passWord as placeholders above.)
UPDATE: I fixed the port number, and now I get this error:
Cannot connect to database: java.sql.SQLException: Access denied
for user 'userName'#'r236059121.resnet.mySchool.edu' (using
password: YES)
Does this mean I need to configure settings on the database? Or does it mean that I've got the credentials wrong? (They work for PHP scripts deployed on the server that contains the database.)
SOLUTION: Added the host above to the Access Host list on cPanel.

Seems to me like your database is not reachable and you will probably get an error when the call runs into a timeout. Are you sure the hostname and port are right and reachable from your machine?
You don't need the newInstance() at the end of Class.forName(). Class.forName() triggers the classloader to load that class, which in turn triggers some internal registration code in the driver which makes the driver available.

I think the line should just be
Class.forName("com.mysql.jdbc.Driver");
(close the .newInstance() bit)
That causes the driver to register itself with the driver manager and allows the driver manager to pick a driver for the database url.
I think the hang is caused by a DNS problem, or some other reason why your db cannot be reached. By default, the MySQL JDBC driver does not time out for a connection. See http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-configuration-properties.html and look for connectTimeout.
In your code, you have
String url = "jdbc:mysql://www.domainName.com:portNumber/databaseName";
I take it that you used a real port there? By default, it should be 3306. You can test with the test database which is present in virtually all mysql instances:
String url = "jdbc:mysql://www.domainName.com:3306/test";
You also wrote:
String username = "myUserName";
String password = "myPassWord";
Obviously you should use real credentials here too. Ask your dba what they are. If you're the DBA then...well you should probably read up on MySQl administration :) Seriously when you installed MySQL you were probably promted for a password for the root user. Use those (in the obvious way)
In real code you should probably not hang when the db is not there. So I advise adding a connectTimeout option like so:
String url = "jdbc:mysql://www.domainName.com:3306/test?connectTimeout=3000";
(connectTimeout is in milliseconds, so this would time out after 3 seconds)

Rosarch - You are not able to connect to your DB since its unreachable.
It'll timeout after a while.
Try telnetting -
telnet <IP-OF-domainName.com> <PortNumber>
You'll mostly see that it shows timeout.
Solutions -
1.) If you are behind a firewall, you need to punch a hole to allow access
2.) If you are behind a proxy, need to configure it to allow access