derby

问题 I've been messing around with Apache Derby inside Eclipse. I've booted up a Network Server, and I've been working with servlets. In my Eclipse project, I have a class called "User", inside the package "base.pack". I have an SQL script open, and I've been trying to convert User, which implements Serializable, into a custom type. When I run the following lines, everything works fine: CREATE TYPE CARTEBLANCHE.bee EXTERNAL NAME 'base.pack.User' LANGUAGE JAVA This follows the general format they

问题 I am rather new to Java and JavaDB. I am trying to create a database in Netbeans 7.0.1 and after the server starts, I get an error that says: "An error occurred while creating the database: java.sql.SqlNonTransientConnectionException: A communications error has been detected: Software caused connection abort: recv failed.." I have tried to disable my antivirus (Microsoft Security Essentials) and my Windows Firewall, as well as disable an internet filter(Contentwatch's NetNanny) all to no

问题 I have problem with my project. My apache derby generate id, in table it works. But in app it doesnt work. In derby I set id autoincrement (start with 1, increment by 1), but i get this error: > Caused by: ERROR 42Z23 : An attempt was made to modify the identity > column ' ID' . My entity: package com.springapp.mvc.models; import javax.persistence.*; @Entity @Table(name = "USERS", schema = "KK", catalog = "") public class UsersEntity { private int id; private String name; private String

问题 In JDBC metadata is not set, if the result set is empty, so I cannot execute getColumnNames(). I tried querying the derby systables: The SYS.SYSTABLES table contains REFERENCEID , COLUMNAME , COLUMNUMBER , ... COLUMNAME is what I'm searching for. But I see no possibility to join this table with SYS.SYSTABLES or any other table. 回答1: You can join systables and syscolumns with TABLEID = REFERENCEID select TABLENAME,COLUMNNAME, t.* FROM sys.systables t, sys.syscolumns WHERE TABLEID = REFERENCEID

问题 I am making a small application and I am using the embedded derby database ,I want the application to be able to save the whole database onto a single file which can be stored on the hard drive and also import the database by opening this file in the future.Any clues or examples on how can I do it? 回答1: This might help you out! 1- Resource 1 with all detail 2- Resource 2 with Export Detail only 3- Using Java to Export/Import Using Jdbc To export all the data from a table to a single export

问题 I would like to convert an existing Derby database to MySQL. 回答1: Try the DBCopy Plugin for SQuirreL SQL Client if you only need to convert the database once. There are other tools that may work. I you need to convert regularly, then I would use CSV export / import (for the data). 来源： https://stackoverflow.com/questions/3744770/how-to-convert-apache-derby-database-to-mysql

问题 I'm using derby for development in eclipse. Is it possible to dump a table from MySQL and use it for derby in some way? I know that ddl & dml are different for both dbms but I'm looking for a way, other than dump/export, that would be appropriate. 回答1: There are two options I can find; if I understand your question correctly, I think at least one will cover what you are looking for. If your focus is the data (or a subset thereof) from a single table, use ij as indicated in the Derby tools

问题 I have: BoneCP CONNECTION_POOL = ...; CONNECTION_POOL.getConfig().setJdbcUrl("jdbc:derby:database...;shutdown=true"); Connection connection = CONNECTION_POOL.getConnection(); connection.close(); CONNECTION_POOL.shutdown(); However this results in the following exception: 3274 [com.google.common.base.internal.Finalizer] ERROR com.jolbox.bonecp.ConnectionPartition - Error while closing off internal db connection java.sql.SQLException: Cannot close a connection while a transaction is still

问题 I am trying to alter a datatype for a derby db column. The current price column is set as DECIMAL(5,0). I would like to alter it to DECIMAL(7,2). I did this : alter table item alter column price set data type DECIMAL(7,2); But it did not work, and showing the error: Error: Only columns of type VARCHAR may have their length altered. May I know how is it possible to alter it? Thank you. 回答1: Here is the Derby SQL script to change column MY_TABLE.MY_COLUMN from BLOB(255) to BLOB(2147483647):

问题 I am trying to insert into a table without duplicates. I am using SQL derbyclient in Java. The code is not working (error with 'where not exists' ). Any idea? Connection connection = DriverManager.getConnection("jdbc:derby://localhost:1527/PetroleumDataStorageSystemDB;create=true"); PreparedStatement statement; int i = 1; int progress = 0; for (Refuel refuelList1 : refuelList) { progress = (i / refuelList.size()) * 100; String sql = "INSERT INTO refuel (id_tank, time, fuel_volume, " +