I need to connect to a remote database using Database link using JDBC commands.
How can it be done?
If you already have the dblink setup, you can utilize it in your SQL (sent via jdbc) by addressing the required tables like such:
select * from SCHEMA.TABLE#DBLINK_NAME
Using this query inside of your java would look something like this
public ResultSet execQuery() throws SQLException, ClassNotFoundException{
//Load the database driver
Class.forName("oracle.jdbc.OracleDriver");
//Create connection to the database
Connection myConnection = DriverManager.getConnection(connectURL,userName,userPwd);
//Create a statement link to the database for running queries
Statement myQuery = myConnection.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
//Create a resultSet to hold the returned query information
ResultSet myQueryResults = myQuery.executeQuery("select * from SCHEMA.TABLE#DBLINK_NAME");
return myQueryResults;
}
*java & oracle assumed
If you are asking about how to use JDBC to create a link between the DB you are talking to and another one, then it is "just SQL" that you (presumably) would execute in the same way as you would any other SQL statement. (If you tell us which DB you are using, we could talk about the actual SQL you need to execute.)
Otherwise, I don't think this makes sense. A DB link / Database link is a link from one database to another. But JDBC is for talking to a database from a Java client. It makes no sense (to me) to use DB link to connect a JDBC client to a database.
Please take a look at orajdbclink, on sourceforge
I am planning to to connect my oracle plsql sources to phoenix skin of hbase. It seems to me the unique way to create a connector between oracle and hbase for the moment...
Related
I want to use sqlite driver for my java application that I am developing with netbeans. What would be the correct "design" when it comes to integrating DB queries?
Basically should I create a static variable holding the connection which I can use to execute SQL statements through out the app? Or should I create the connection everytime I want to do the query?
Here is my code
Class.forName("org.sqlite.JDBC");
conn = DriverManager.getConnection("jdbc:sqlite:Mydb.db");
st = conn.createStatement();
rs = st.executeQuery(/*My sql statement*/);
Thank you
Creating connection every time you write a query is not a good approach because it will be an overload on database for handling multiple connections.
Rather you should prefer a method or a class which would return you an instance of database connectivity.
I am having a problem. I have a query that checks one database table and updates another database table. I am using MySQL 5.1
UPDATE dldd.temp,test.temp
SET test.temp.name = dldd.temp.word
WHERE dldd.temp.id = test.temp.id
this is my SQL statement that is working fine. Now I want to execute this statement using Java PreparedStatement . The problem is I don't know how to write the Connection String to select two database i.e
"jdbc:mysql://localhost:3306/"+dbname+"?characterEncoding=UTF-8"
What should come in place of dbname. Can I select multiple db there.
Have a look at http://dev.mysql.com/doc/connector-j/en/connector-j-reference-configuration-properties.html.
If the database is not specified, the connection is made with no default database. In this case, either call the setCatalog() method on the Connection instance, or fully specify table names using the database name (that is, SELECT dbname.tablename.colname FROM dbname.tablename...) in your SQL. Opening a connection without specifying the database to use is generally only useful when building tools that work with multiple databases, such as GUI database managers.
Running Netcool 7.3.1. Looking for simple api to access Object Server Tables. I've already done the run an SQL command from nco_sql, and scraped the output into a C# data table, but wondering if there was some type of api that I could use for either C# or Java to access table data?
If you can use a more up-to-date version of Omnibus, you can use the built-in HTTP / REST API.
http://www-01.ibm.com/support/knowledgecenter/SSSHTQ_8.1.0/com.ibm.netcool_OMNIbus.doc_8.1.0/omnibus/wip/api/concept/omn_api_http_overview.html?lang=en
You may need to use sybase database adapter so far I have used below three ways to query netcool object server:
Free TDS - This is free sybase client.
Jconn3 - this is paid sybase client, but if you are using WebGUI/Impact, this driver comes with TIP.
nco_sql - here you may need to create a file with query and then pass it to nco_sql. This require extra effort to parse column wise information as output will be on console.
I prefer jconn3, simple and similar to jdbc driver, you only need this jar in classpath.
You can write your own java program to connect to Objectserver by simply initiating
//Load Sybase Driver
Class.forName("com.sybase.jdbc3.jdbc.SybDriver");
String url = "jdbc:sybase:Tds:" + host + ":" + port;
con = DriverManager.getConnection(url, user, pass);
Execute Statements
Statement stat = conn.createStatement();
ResultSet result = stat.executeQuery("Select count(*) from alerts.status");;`
I have tried to connect the mysql database with the frontend with the help of JDBC driver. But i dont know how acna we implement connectivity to connect the two different databases with each other with the help of JDBC driver.
You can create two connections. One for the first database and the other for the second database. You can send commands to the first database using the first connection and you can send commands to the second database using the second connection. Your application will serve the purpose of connecting the two databases as you can select rows from one database, parse them and insert the resulting records into the other.
There is no magic in JDBC that allows you to 'connect the two database with each other'. You need to code this yourself. You create two connections, one for each database and then you write the queries and transformations to get your data from database 1 to database 2.
try (
Connection connectionToDb1 = DriverManager.getConnection(
"jdbc:firebirdsql://serverA/database1", "username", "password");
Connection connectionToDb2 = DriverManager.getConnection(
"jdbc:firebirdsql://serverB/database2", "username", "password");
Statement selectFrom1 = connectionToDb1.createStatement();
ResultSet rsFrom1 = selectFrom1.executeQuery(
"SELECT columnA, columnB FROM tableX");
PreparedStatement insertTo2 = connectionToDb2.prepareStatement(
"INSERT INTO tableY(column1, column2) VALUES (?, ?)");
) {
while (rsFrom1.next()) {
insertTo2.setString(1, rsFrom1.getString("columnA"));
insertTo2.setString(2, rsFrom1.getString("columnB"));
insertTo2.executeUpdate();
}
}
Note that this isn't a complete example: for production purposes you would disable auto commit, and use batch updates.
There are tools that can do this for you, but tool and library suggestions are off topic on SO, but I'd suggest you search for ETL (or extract, transform, load), or maybe for datapump.
I'm trying to do with java and mysql the same I am used to with .net and SQL server:
By using Microsoft.SqlServer.Management.Smo I can access database structure information from my instance ( server name, table structure, columns, datatype, description, default value)
I tried to find to do the same with Java + MYSQL but it seems it is not so popular
any directions?
thanks
Ed
The simplest way to accomplish it is by retrying the connection metadata, first you open a connection:
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db", "user","****");
DatabaseMetaData metaData = conn.getMetaData();
then start navigating through the metadata, you can check the available operations in DatabaseMedata
DatabaseMetaData will be useful for your requirement.
please also check nearly similar stackoverflow question
use the DatabaseMetadata for get database related information.
Database Metadata