Java Connection String to query from two database - java

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.

Related

How to connect two database through JDBC? Is it possible?

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.

how to check database user permission on fmp database using JAVA

I want to know how to run FileMaker(FMP pro) database command in java. I have got the connection to database,but not sure how to execute below query.
Get(AccountPrivilegeSetName)
ref:
http://www.filemaker.com/11help/html/func_ref2.32.4.html#1051898
You will need to add a calculation field in FileMaker to return as the result of the JDBC query. This is because you cannot call functions via JDBC, you can only retrieve field values.

Change Table names in derby database using entitymanager

I am using an APACHE DERBY database, and basing my database interactions on EntityManager, and I don't want to use JDBC class to build a query to change my tables' names (i just need to put a prefix to each new user to the application, but have the same structure of tables), such as:
//em stands for EntityManager object
Query tableNamesQuery= em.createNamedQuery("RENAME TABLE SCHEMA.EMP_ACT TO EMPLOYEE_ACT");
em.executeUpdate();
// ... rest of the function's work
// The command works from the database command prompt but i don't know how to use it in a program
//Or as i know you can't change system tables data, but here's the code
Query tableNamesQuery= em.createNamedQuery("UPDATE SYS.SYSTABLES SET TABLENAME='NEW_TABLE_NAME' WHERE TABLETYPE='T'");
em.executeUpdate();
// ... rest of the function's work
My questions are :
This syntax is correct?
Will it work?
Is there any other alternative?
Should I just use the SYS.SYSTABLES and find all the tables that has 'T' as tabletype and alter their name their, will it change the access name ?
I think you're looking for the RENAME TABLE statement: http://db.apache.org/derby/docs/10.10/ref/rrefsqljrenametablestatement.html
Don't just issue update statements against the system catalogs, you will corrupt your database.

Hibernate multiple native SQL statements

I want to run a native SQL from a file using Hibernate. The SQL can contain several statements creating the database structure (i.e. tables, constraints but no insert/update/delete statements).
Example, very simple query is below (which contains the following two SQL statements)
CREATE DATABASE test;
CREATE TABLE test.testtbl( id int(5));
I am using MySQL db, and when I run the above query I am gettng syntax error returned. When I run them one by one, its ok.
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException:
You have an error in your SQL syntax; check the manual that corresponds to your
MySQL server version for the right syntax to use near
'CREATE TABLE test.testtbl( id int(5))' at line 1
The code to run the query is below (above statement is assigned to 'sql' variable):
session = sf.openSession();
session.beginTransaction();
Query qry = session.createSQLQuery(sql);
qry.executeUpdate();
session.getTransaction().commit();
Any help would be appreciated.
As others have explained
You must run these queries one by one.
The hibernate code gets translated into running one update statement on JDBC.
But you provided two update statements.
In addition,
I personally prefer to have the code that creates tables outside of the Java application, in some DB scripts.
The parameters of the method createSQLQuery is t-sql code;
t-sql code to ensure that in the mysql interface analyzer correctly.
You can try changed the sql :'CREATE TABLE testtbl(id int(5));'
by the way you can use JDBC Connection api (Don't recommend to do so)
Such as:
java.sql.Connection conn=session.connection();

How to connect to remote database through DB link using JDBC?

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...

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