Solved

h2 database issue in java

Posted on 2013-11-27
4
1,510 Views
Last Modified: 2013-12-12
Hi;

I write the following code to test a simple h2 database and table, but failed. Code is as follows:

import java.sql.Connection;  
import java.sql.DriverManager;  
import java.sql.ResultSet;  
import java.sql.Statement;  

public class H2Example {  
    public static void main(String[] args) {  
  
        Connection connection = null;  
        ResultSet resultSet = null;  
        Statement statement = null;  
  
        try {  
            Class.forName("org.h2.Driver");  
            connection = DriverManager.getConnection(  
                    "jdbc:h2:C:\\H2DB\\database\\EMPLOYEEDB", "sa", "");  
            statement = connection.createStatement();  
            resultSet = statement  
                    .executeQuery("SELECT EMPNAME FROM EMPLOYEEDETAILS");  
            while (resultSet.next()) {  
                System.out.println("EMPLOYEE NAME:"  
                        + resultSet.getString("EMPNAME"));  
            }  
        } catch (Exception e) {  
            e.printStackTrace();  
        } finally {  
            try {  
                resultSet.close();  
                statement.close();  
                connection.close();  
            } catch (Exception e) {  
                e.printStackTrace();  
            }  
        }  
    }  
}  

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The latest jar is in buildpath in my eclipse. The path for db is as C:\H2DB\database\EMPLOYEEDB.h2

The error is as follows:

org.h2.jdbc.JdbcSQLException: Table "EMPLOYEEDETAILS" not found; SQL statement:
SELECT EMPNAME FROM EMPLOYEEDETAILS [42102-174]
	at org.h2.message.DbException.getJdbcSQLException(DbException.java:332)
	at org.h2.message.DbException.get(DbException.java:172)
	at org.h2.message.DbException.get(DbException.java:149)
	at org.h2.command.Parser.readTableOrView(Parser.java:4942)
	at org.h2.command.Parser.readTableFilter(Parser.java:1159)
	at org.h2.command.Parser.parseSelectSimpleFromPart(Parser.java:1766)
	at org.h2.command.Parser.parseSelectSimple(Parser.java:1874)
	at org.h2.command.Parser.parseSelectSub(Parser.java:1760)
	at org.h2.command.Parser.parseSelectUnion(Parser.java:1602)
	at org.h2.command.Parser.parseSelect(Parser.java:1590)
	at org.h2.command.Parser.parsePrepared(Parser.java:418)
	at org.h2.command.Parser.parse(Parser.java:290)
	at org.h2.command.Parser.parse(Parser.java:262)
	at org.h2.command.Parser.prepareCommand(Parser.java:227)
	at org.h2.engine.Session.prepareLocal(Session.java:437)
	at org.h2.engine.Session.prepareCommand(Session.java:380)
	at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1138)
	at org.h2.jdbc.JdbcStatement.executeQuery(JdbcStatement.java:72)
	at H2Example.main(H2Example.java:23)
java.lang.NullPointerException
	at H2Example.main(H2Example.java:32)

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The table is there as seen in the screenshot.

Regards.
h2.jpg
0
Comment
Question by:jazzIIIlove
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4 Comments
 
LVL 86

Expert Comment

by:CEHJ
ID: 39680591
That image shows an entirely different path - not even a Windows OS
0
 
LVL 35

Assisted Solution

by:mccarl
mccarl earned 250 total points
ID: 39680640
It looks like you might be missing the .h2 extension of your DB file in the URL on line 16 of your code, ie. it should be like this...
            connection = DriverManager.getConnection(  
                    "jdbc:h2:C:\\H2DB\\database\\EMPLOYEEDB.h2", "sa", "");

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Also, to prevent the NullPointerException at the end of the error that you posted, you should check each resource for null when closing them in the finally block, such as...
         } finally {  
            try {  
                if (resultSet != null) {
                    resultSet.close();  
                }
                if (statement != null) {
                    statement.close();   
                }
                if (connection != null) {
                    connection.close();   
                }
            } catch (Exception e) {  
                e.printStackTrace();  
            }  
        }

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0
 
LVL 86

Accepted Solution

by:
CEHJ earned 250 total points
ID: 39680744
Try instead:

connection = DriverManager.getConnection("jdbc:h2:~/test", "sa", "");

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As it looks like a Unix-path fits all kind of thing
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 39713786
:)
0

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