-
MY PROJECTS
-
Recent Posts
- SQL.How can you compare two nullable values safely, and how does IS DISTINCT FROM differ from <>?
- SQL.How are NULL values ordered by ORDER BY, how do defaults differ between databases, and how can you control their placement?
- SQL.How does NULL propagate through arithmetic expressions, and how can COALESCE and NULLIF help handle missing values and division by zero?
- SQL.How does NULL affect join conditions, and why can filtering the right-hand table in WHERE remove unmatched rows from a LEFT JOIN?
- SQL.How do GROUP BY and DISTINCT treat NULL values, even though NULL = NULL evaluates to UNKNOWN?
- SQL.How do aggregate functions handle NULL, and what is the difference between COUNT(*), COUNT(column), and COUNT(DISTINCT column)?
- SQL.How does NULL affect IN and NOT IN, and why can NOT EXISTS be a safer choice when a subquery returns nullable values?
- SQL.How do WHERE, HAVING, and CHECK constraints treat conditions that evaluate to UNKNOWN?
- SQL.Why do column = NULL and column <> NULL not work as expected, and when should you use IS NULL and IS NOT NULL?
- SQL.What is SQL’s three-valued logic (TRUE, FALSE, UNKNOWN), and how do AND, OR, and NOT behave with UNKNOWN?
- ChromeDevTools.Watch all failed requests
- SQL.What are domain types (or constraints on data types), and how do they help enforce data correctness?
- SQL.How does SQL handle comparisons between different data types (for example, string vs number), and why is this dangerous?
- SQL.What is the difference between DATE, TIME, TIMESTAMP, and TIMESTAMPTZ, and which one should be used for business events?
- SQL.How do numeric types like INTEGER, BIGINT, DECIMAL, and FLOAT differ in terms of precision and use cases?
- SQL.What problems can arise from implicit type casting in SQL, and how can it affect indexes?
- SQL.How does NULL differ from 0, an empty string, or FALSE in SQL?
- SQL.What is the difference between CHAR, VARCHAR, and TEXT, and when would you choose each?
- SQL.What is MVCC ?
- SQL.What is AutoVacuum Postgres ?
Categories
- Aptana
- Azure
- C#
- DataSnap
- DBExpress
- Delphi
- Delphi и сети
- Delphi. Язык программирования
- ExtJS
- FastReport
- FireDAC
- FireMonkey
- GIT
- ICS
- IDE
- IIS
- Indy
- InnoSetup
- javascript
- jQuery
- JSON
- LiveBindings
- MSHTML
- MySQL
- PHP
- REST
- Ribbons
- SMS
- SQL инструкции
- SVN
- TRichView
- UniGui
- WebBroker
- WinAPI
- Windows
- Алгоритмы
- Без рубрики
- Деревья
- Ищу ответ
- Компонентостроение
- Мои компоненты
- Начальный уровень
- Обработка исключений
- Парсинг
- Потоки(Threads)
- Регулярные выражения
- Тестирование приложений
Author Archives: Stanislav_Panteleev
Java.SpringBoot.PopularAnnotations
@BeanAnnotations @EnableAsync / @Async ; do smth in new thread @EnableSheduling / @Scheduled @Lock ; lock record on database level @Mdifying ; to learn @Scheduled @Query
Posted in Без рубрики
Comments Off on Java.SpringBoot.PopularAnnotations
SpringBoot. Exception Management
in rus https://struchkov.dev/blog/ru/exception-handling-controlleradvice/ validation handling https://struchkov.dev/blog/ru/spring-boot-validation/
Posted in Без рубрики
Comments Off on SpringBoot. Exception Management
Java.Hibernate.JoinTableAnnotation
https://stackoverflow.com/questions/5478328/in-which-case-do-you-use-the-jpa-jointable-annotation
Posted in Без рубрики
Comments Off on Java.Hibernate.JoinTableAnnotation
SpringBoot.Making our first starter and autoconfiguration
STARTER let’s create some new module and infra package in it MAIN APP in main app we can call and use this bean like this
Posted in Без рубрики
Comments Off on SpringBoot.Making our first starter and autoconfiguration
Spring. Creating main annotation to start business logic
a couple of classes with business logic
Posted in Без рубрики
Comments Off on Spring. Creating main annotation to start business logic
Spring.Reading from properties file
Any beanFactoryPostProcessor should be declared in @Configuration file with static, because configuration is being initialized in very begining. Nothing needed, props a read from application.properties / application.yml file, but if you want to custmomize the file you can add annotation … Continue reading
Posted in Без рубрики
Comments Off on Spring.Reading from properties file
Spring.How to define spring version inside springBoot ?
another way
Posted in Без рубрики
Comments Off on Spring.How to define spring version inside springBoot ?
SpringBoot App inside Docker
Commands // rebuild some service in docker compose // start all containers in docker compose // down all containers Files Dockerfile docker-compose.yml
Posted in Без рубрики
Comments Off on SpringBoot App inside Docker
Kafka.FirstExperience
docker-compose.yml go to the directory of file and type kafka container console create topic list all topics writing to topic reading wrom topic
Posted in Без рубрики
Comments Off on Kafka.FirstExperience
Docker.MySql and Lost connection to MySQL server at ‘reading initial communication packet’, system error: 0
If you’re trying to connect from outside of Docker, your docker run -p option is wrong: the second port number always needs to be the standard port number of its service. For MySQL, that second port number needs to be 3306, always. The two … Continue reading
Posted in Без рубрики
Comments Off on Docker.MySql and Lost connection to MySQL server at ‘reading initial communication packet’, system error: 0