又是一個不知所謂的derby的cousor功能

stmt.executeUpdate("UPDATE SAMP.STAFF SET COMM = " +
"COMM + 20 " + "WHERE CURRENT OF " + ResultSet.getCursorName());

自由到，覺得有點怪??

derby 的進階功能，call procedure，call function

能簡單的call function是重要的，
相對於
sybase還要花8萬，
真讓人不爽，

derby的效能是差在那裏呢?

embeded的db，web server，所有皆可可攜性。

這是範例??

CREATE FUNCTION TO_DEGREES(RADIANS DOUBLE) RETURNS DOUBLE
PARAMETER STYLE JAVA NO SQL LANGUAGE JAVA
EXTERNAL NAME 'java.lang.Math.toDegrees'

這是什麼鬼創建方式??

真的假的。

Example

CREATE PROCEDURE SALES.TOTAL_REVENUE(IN S_MONTH INTEGER,
IN S_YEAR INTEGER, OUT TOTAL DECIMAL(10,2))
PARAMETER STYLE JAVA READS SQL DATA LANGUAGE JAVA EXTERNAL NAME
'com.acme.sales.calculateRevenueByMonth'

第三行後就不知所謂了。

也太像寫作文了吧

derby的流水號欄位，及範例

CREATE TABLE HOTELAVAILABILITY
    (HOTEL_ID INT NOT NULL, BOOKING_DATE DATE NOT NULL,
 ROOMS_TAKEN INT DEFAULT 0, PRIMARY KEY (HOTEL_ID, BOOKING_DATE));
-- the table-level primary key definition allows you to
-- include two columns in the primary key definition
PRIMARY KEY (hotel_id, booking_date))
-- assign an identity column attribute to an INTEGER
-- column, and also define a primary key constraint
-- on the column
CREATE TABLE PEOPLE
 (PERSON_ID INT NOT NULL GENERATED ALWAYS AS IDENTITY
 CONSTRAINT PEOPLE_PK PRIMARY KEY, PERSON VARCHAR(26));
-- assign an identity column attribute to a SMALLINT
-- column with an initial value of 5 and an increment value
-- of 5.
CREATE TABLE GROUPS
 (GROUP_ID SMALLINT NOT NULL GENERATED ALWAYS AS IDENTITY
 (START WITH 5, INCREMENT BY 5), ADDRESS VARCHAR(100), PHONE VARCHAR(15));

用力找時，反而找不到，不用力找時，反而很多。

http://db.apache.org/derby/docs/10.2/devguide/

http://db.apache.org/derby/docs/10.2/ref/

CREATE TABLE MAPS
(
MAP_ID INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1),
MAP_NAME VARCHAR(24) NOT NULL,
REGION VARCHAR(26),
AREA DECIMAL(8,4) NOT NULL,
PHOTO_FORMAT VARCHAR(26) NOT NULL,
PICTURE BLOB(102400),
UNIQUE (MAP_ID, MAP_NAME)
)

always 算是關鍵字，總覺得不太習慣。
整個句子拉得很長!
它的參數也別具風格，
自定一個db也算是愈來愈接近了。
高興的語法。
中文式的開table法。

或是中文欄位，當然是unicode的中文。

所以網路上所有用mysql的範例，要相對的修改。


有不少erp是不用自動加1欄位的。

終於，快要下一步

Exception in thread "main" org.hibernate.id.IdentifierGenerationException: ids for this class must be manually assigned before calling save(): kt.com.User
at org.hibernate.id.Assigned.generate(Assigned.java:33)

全天下都是照抄範例

derby 也有啊

Exception in thread "main" org.hibernate.InvalidMappingException: Could not parse mapping document from resource kt/com/User.hbm.xml

Caused by: org.hibernate.InvalidMappingException: Could not parse mapping document from invalid mapping
at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:502)
at org.hibernate.cfg.Configuration.addResource(Configuration.java:566)
... 7 more
Caused by: org.xml.sax.SAXParseException: The content of element type "class" must match "(meta*,subselect?,cache?,synchronize*,comment?,tuplizer*,(id|composite-id),discriminator?,natural-id?,(version|timestamp)?,(property|many-to-one|one-to-one|component|dynamic-component|properties|any|map|set|list|bag|idbag|array|primitive-array)*,((join*,subclass*)|joined-subclass*|union-subclass*),loader?,sql-insert?,sql-update?,sql-delete?,filter*,resultset*,(query|sql-query)*)".


//CREATE TABLE user1 (
// id INT NOT NULL PRIMARY KEY,
// name VARCHAR(100) NOT NULL default '',
// age INT
//);

derby 的流水號欄位，怪，找不到

一直節外生枝

Hibernate 滿是挫折中…

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not get or update next value
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:67)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.engine.TransactionHelper$1Work.doWork(TransactionHelper.java:41)
at org.hibernate.engine.transaction.Isolater$JdbcDelegate.delegateWork(Isolater.java:187)
at org.hibernate.engine.transaction.Isolater.doIsolatedWork(Isolater.java:43)
at org.hibernate.engine.TransactionHelper.doWorkInNewTransaction(TransactionHelper.java:51)
at org.hibernate.id.TableGenerator.generate(TableGenerator.java:94)
at org.hibernate.id.TableHiLoGenerator.generate(TableHiLoGenerator.java:61)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:99)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519)
at kt.com.FirstHibernate.main(FirstHibernate.java:29)
Caused by: java.sql.SQLException: Table/View 'HIBERNATE_UNIQUE_KEY' does not exist.
at org.apache.derby.client.am.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
at org.apache.derby.client.am.Connection.prepareStatement(Unknown Source)
at org.hibernate.id.TableGenerator.doWorkInCurrentTransaction(TableGenerator.java:131)
at org.hibernate.engine.TransactionHelper$1Work.doWork(TransactionHelper.java:38)
... 15 more
Caused by: org.apache.derby.client.am.SqlException: Table/View 'HIBERNATE_UNIQUE_KEY' does not exist.
at org.apache.derby.client.am.Statement.completeSqlca(Unknown Source)
at org.apache.derby.client.net.NetStatementReply.parsePrepareError(Unknown Source)
at org.apache.derby.client.net.NetStatementReply.parsePRPSQLSTTreply(Unknown Source)
at org.apache.derby.client.net.NetStatementReply.readPrepareDescribeOutput(Unknown Source)
at org.apache.derby.client.net.StatementReply.readPrepareDescribeOutput(Unknown Source)
at org.apache.derby.client.net.NetStatement.readPrepareDescribeOutput_(Unknown Source)
at org.apache.derby.client.am.Statement.readPrepareDescribeOutput(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.readPrepareDescribeInputOutput(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.flowPrepareDescribeInputOutput(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.prepare(Unknown Source)
at org.apache.derby.client.am.Connection.prepareStatementX(Unknown Source)
... 18 more