Resolved - @PreUpdate not working in JUnit test.

 



javax.persistence.PreUpdate

object need to be "dirty" to trigger...

obj.setColumn01("text");

repo.save(obj);

then make obj "dirty" before save to trigger @PreUpdate


obj.setColumn01("new text);
repo.save(obj);

Reference URL: https://www.javafixing.com/2021/12/fixed-preupdate-does-not-work-with.html

Solution

As you said, the callback method is called the second time, if the entity is detached or fetched again from DB.

I cannot explain it exactly, but can think of the scenario described here, when no dirty fields are identified before the second save() call and thus the @PreUpdate callback not called. Or it may be simply a bug within your version of EclipseLink.

Cannot access locahost:8080/h2-console for H2Database?

Hint: 

http://localhost:8080/your-web-app/h2-console

Source URL: https://stackoverflow.com/a/43230667

Check if you set a base path in application.properties.

For example, if you have a setting

server.contextPath=/api

You access the h2 Console under

http://localhost:8080/api/h2-console

Obvious, but that was it for me

Spring JPA

 

怀疑问的发现：

Seems able to join another entity(table) by using reference below:

1. SELECT P.C.attribute FROM Parent AS P;
2. SELECT PCattribute FROM Parent AS P;

datasource c3p0 vs org.apache.commons.dbcp.BasicDataSource

https://stackoverflow.com/questions/520585/connection-pooling-options-with-jdbc-dbcp-vs-c3p0

DBCP is out of date and not production grade. Some time back we conducted an in-house analysis of the two, creating a test fixture which generated load and concurrency against the two to assess their suitability under real life conditions.

DBCP consistently generated exceptions into our test application and struggled to reach levels of performance which C3P0 was more than capable of handling without any exceptions.

C3P0 also robustly handled DB disconnects and transparent reconnects on resume whereas DBCP never recovered connections if the link was taken out from beneath it. Worse still DBCP was returning Connection objects to the application for which the underlying transport had broken.

Since then we have used C3P0 in 4 major heavy-load consumer web apps and have never looked back.

UPDATE: It turns out that after many years of sitting on a shelf, the Apache Commons folk have taken DBCP out of dormancy and it is now, once again, an actively developed project. Thus my original post may be out of date.

That being said, I haven't yet experienced this new upgraded library's performance, nor heard of it being de-facto in any recent app framework, yet.

Hibernate ORM 5.3.11.Final = current stable release

As of 2019-Sep-03_pm021556
Hibernate ORM 5.3.11.Final  = current stable release


Hibernate ORM 5.3.11.Final User Guide.html

https://docs.jboss.org/hibernate/stable/core/userguide/html_single/Hibernate_User_Guide.html#_system_requirements

System Requirements

Hibernate 5.2 and later versions require at least Java 1.8 and JDBC 4.2.

Hibernate 5.1 and older versions require at least Java 1.6 and JDBC 4.0.

Relevant:
https://spring.io/blog/2018/09/21/spring-framework-5-1-goes-ga

Spring Framework 5.1 requires JDK 8 or higher and specifically supports JDK 11 as the next long-term support release. It comes with initial refinements for GraalVM compatibility and deeply integrates with the recently released Reactor Californium and Hibernate ORM 5.3.

No PersistenceProvider - Caused by: java.lang.IllegalArgumentException: No PersistenceProvider specified in EntityManagerFactory configuration, and chosen PersistenceUnitInfo does not specify a provider class name either

Change the emf bean configuration and add a new bean called jpaVendorAdapter:

<bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" id="emf">
  <property name="packagesToScan" value="com.medsoft.stadto.entity" />
  <property name="dataSource" ref="dataSource" />
  <property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
  <property name="persistenceUnitName" value="stadto"/>
  <property name="jpaProperties">
    <props>
      <prop key="hibernate.show_sql">true</prop>
      <prop key="hibernate.hbm2ddl.auto">create</prop>
    </props>
  </property>
</bean>

<bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
  <property name="showSql" value="true"/>
  <property name="generateDdl" value="true"/>
  <property name="databasePlatform" value="org.hibernate.dialect.PostgreSQLDialect"/>
</bean>

Also make sure you have a persistence.xml in the META-INF directory:

<?xml version="1.0"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
  http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"
  version="2.1">
  <persistence-unit name="stadto">
    //No need to specify the provider as we already have specified JPA vendor in applicationContext.xml
  </persistence-unit>
</persistence>

To remove persistence.xml, refer to: https://billson.blogspot.com/2019/08/caused-by-javalangillegalstateexception.html

Caused by: java.lang.IllegalStateException: No persistence units parsed from {classpath*:META-INF/persistence.xml}

Reference URL: https://www.baeldung.com/the-persistence-layer-with-spring-and-jpa

5. Going Full XML-less

Usually, JPA defines a persistence unit through the META-INF/persistence.xml file. Starting with Spring 3.1, the persistence.xml is no longer necessary. The LocalContainerEntityManagerFactoryBean now supports a ‘packagesToScan' property where the packages to scan for @Entity classes can be specified.

This file was the last piece of XML we need to remove. We can now set up JPA fully with no XML.

We would usually specify JPA properties in the persistence.xml file. Alternatively, we can add the properties directly to the entity manager factory bean:

factoryBean.setJpaProperties(this.additionalProperties());

As a side-note, if Hibernate would be the persistence provider, then this would be the way to specify Hibernate specific properties.

add this into your servlet context.xml

<property name="packagesToScan" value="com.howtodoinjava.entity" />

Check mysql access privileges.

resource URL: https://dev.mysql.com/doc/refman/5.5/en/privilege-system.html



SHOW GRANTS FOR user_abc;

Error Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Not a managed type: class java.lang.Object

Understanding the Spring Data JPA @NoRepositoryBean interface

Source URL: https://stackoverflow.com/questions/11576831/understanding-the-spring-data-jpa-norepositorybean-interface

Annotation

@NoRepositoryBean

Solved exception below:

Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Not a managed type: class java.lang.Object

Jackson ObjectMapper writeValueAsString StackOverflowError

com.fasterxml.jackson.databind.JsonMappingException: Infinite recursion (StackOverflowError) (through reference chain: com.vividsolutions.jts.geom.Point["envelope"]->           repeat 997 times           ->com.vividsolutions.jts.geom.Point["envelope"])



Working solution URL: https://github.com/bedatadriven/jackson-datatype-jts/issues/8

ObjectMapper om = new ObjectMapper();
om.registerModule( new com.bedatadriven.jackson.datatype.jts.JtsModule.JtsModule() );

Caused by: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Cannot get geometry object from data you send to the GEOMETRY field

Environment:

JDK 1.7.0_80

Tomcat 8.0.36

MySql 5.5.50

Spring 4.3.16.RELEASE

Hibernate 4.3.11.Final

Hibernate Spatial 4.3

Caused by: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Cannot get geometry object from data you send to the GEOMETRY field

Getting fail to store Polygon Shape Object in Geometry Datatype with hibernate spatial API

URL: https://gis.stackexchange.com/questions/88564/getting-fail-to-store-polygon-shape-object-in-geometry-datatype-with-hibernate-s?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa

Check column after insert:

SELECT AsText( geometry_column ) FROM table;

MySql: Check each database size running in mysql.

Source URL: http://stackoverflow.com/questions/1733507/how-to-get-size-of-mysql-database

SELECT table_schema                                        "DB Name", 

   Round(Sum(data_length + index_length) / 1024 / 1024, 1) AS "DB Size in MB" 

FROM   information_schema.tables 

GROUP  BY table_schema

ORDER BY Round(Sum(data_length + index_length) / 1024 / 1024, 1) DESC;

SELECT table_schema                                        "DB Name", 
   Round(Sum(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB" 
FROM   information_schema.tables 
GROUP  BY table_schema;

MySql Error code 1017

# mysql connected.
# able to run use database.
# cannot do query select statement.
# run CHECK TABLE, found: cannot find file frm errno 13
# cannot run REPAIR TABLE
# cannot dump databases using: mysqldump





Source URL: http://stackoverflow.com/questions/6443428/cant-find-file-ci-users-frm-errno-13

Example solution in URL above: chown mysql:mysql /var/lib/mysql/ci/*

go to mysql database data folder:

cd /opt/Program/mysql/data/yourdatabase/

chown mysql:mysql *

MySql Select statement export to a file.

SELECT column_a, column_b, column_c FROM tb_abc INTO OUTFILE 'C:/folders/location/tb_abc.txt' FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' LINES TERMINATED BY '\n';

sql server functions

SQL Server 2000

There are three types of UDF in Microsoft SQL Server 2000:

1. Scalar functions.
2. Inline table-valued functions.
3. Multistatement table-valued functions.

Scalar functions return a single data value (not a table) with RETURNS clause. Scalar functions can use all scalar data types, with exception of timestamp and user-defined data types. Inline table-valued functions return the result set of a single SELECT statement. Multistatement table-valued functions return a table, which was built with many TRANSACT-SQL statements.

User-defined functions can be invoked from a query like built-in functions such as OBJECT_ID, LEN, DATEDIFF, or can be executed through an EXECUTE statement like stored procedures.

The Structure of Stored Procedures

The Structure of Stored Procedures
(from SQL SERVER 2000 Stored Procedure Programming)

We will pause aminute to explain the structure of a stored procedure.
A stored procedure encapsulates a relatively simple Select statement for later use.
It returns a recordset containing values from the Selected column.

The recordset will contain only records that matched with the WHERE statement.

The code of a stored procedure consists of a header and a body.

The header of the stored procedure defines external attributes of the stored procedure—its name and a list of one or more parameters.

A example stored procedure has two parameters.
Parameter names must start with the @ character.
The developer must also define a datatype for each parameter.
The header must begin with the Create Procedure keyword and finish with the As keyword.

The body of the stored procedure contains the Transact-SQL statements to be executed when the stored procedure runs.

In this example, there is just one Select statement using the procedure parameters.