Database lock acquisition failure and hsqldb

Question

I was trying to connect to a hsql db. I created one by running from C:\\myhsql:

java -cp .;C:\\hsql\\lib\\hsqldb.jar org.hsqldb.Server -database.0 file:db\\m         


        

Answer 1

Whatever way you have tried is correct.

You don't have to start the HSQLDB Server using seperate java command, below line is not required, as it will lock the database. Prevent other process from starting and locking db.

java -cp .;C:\hsql\lib\hsqldb.jar org.hsqldb.Server -database.0 file:db\mydb -dbname.0 MYDB

just run the jdbc program

java -cp hsqldb.jar  HSQLAccess 

below line

jdbc:hsqldb:file:db/sjdb

will start the database and will give result.

in this way you don't have to start the server seperately, just have to run the program, which will start and stop HSQLDB for you.

import java.sql.*;

public class HSQLAccess {

    public static void main(String args[]) throws Exception
    {
        Connection con = null;
        try
        {
            Class.forName("org.hsqldb.jdbcDriver");         
            con = DriverManager.getConnection("jdbc:hsqldb:file:db/sjdb", "sa","");    

            Statement st = con.createStatement();
            ResultSet rs = st.executeQuery("SELECT * FROM CMDS_WO_MASTER");
            while(rs.next())
            {
                System.out.println(rs.getString(1));
            }

            con.close();

        }
        catch(Exception ex )
        {
            ex.printStackTrace();
        }
        finally
        {
            if(con!=null)
            {
                 con.close();
            }
        }
    }
}