- Question 1. What Is Ibatis ? …
- Question 2. What Isn’t Ibatis ? …
- Question 3. What Is Orm? …
- Question 4. Is Hibernate And Ibatis Can Be Used On One Application? …
- Question 5. What Is The Difference Between Hibernate And Ibatis In Java? …
- Question 6. …
- Question 7. …
- Question 8.
MyBatis 10 minute overview
iBATIS provides two different transaction management options: local and global. Local transactions are managed within the scope of a single SQL statement, while global transactions span multiple SQL statements. iBATIS also provides support for JTA transactions, which allow for transactions to span multiple resources (including databases, message queues, and so on).
– The first level cache is the session cache, which is associated with a single SqlSession object. This cache is not accessible to other SqlSession objects. – The second level cache is the mapper cache, which is associated with a single mapper (mapper.xml) file. This cache is not accessible to other mapper files. – The third level cache is the global cache, which is shared by all SqlSession objects.
iBATIS uses configuration and mapping files to help manage database interactions. The configuration file is used to set up basic information about the database, such as the driver class and URL. The mapping file is used to map Java objects to database tables, and can also be used to specify SQL queries.
iBATIS is a persistence framework which automates the mapping between SQL databases and objects in Java. It works by providing a layer of abstraction between the database and the Java code, which means that developers do not need to write SQL code themselves. Instead, they can simply write Java code which calls the iBATIS framework, and iBATIS will take care of the rest.
iBATIS is a popular data access framework that is used in Java applications. When applying for a position that involves Java development, it is likely that you will be asked questions about iBATIS. Being prepared for these questions can help you make a strong impression on the hiring manager and increase your chances of getting the job. In this article, we discuss the most commonly asked iBATIS questions and how you should respond.
A custom type handler is a way to tell MyBatis how to map a particular Java type to a corresponding database type. For example, you might want to use a custom type handler to map a Java enum to a VARCHAR column in your database. To do this, you would first create a custom type handler that implements the org.apache.ibatis.type.TypeHandler interface. This interface defines methods for setting and getting values from a prepared statement or resultset. Once you have created your custom type handler, you need to register it with MyBatis. This can be done in the configuration file. Finally, you need to specify that you want to use the custom type handler for a particular Java type when mapping SQL statements.
Lazy loading is a feature that allows MyBatis to delay loading of related objects until they are needed. This can be useful in situations where related objects are not always needed, as it can improve performance by avoiding unnecessary database queries. Lazy loading can be enabled or disabled on a per-mapping basis.
MyBatis is a persistence framework which offers a number of advantages over using JDBC directly. MyBatis eliminates the need for manual mapping of objects to database tables, and it also provides built-in caching to improve performance. MyBatis can also generate SQL dynamically, which can be helpful in situations where the structure of the database may change frequently.
The @MapKey annotation is used to specify the column that should be used as the key for a map that is being returned by a MyBatis query. This is important because it allows you to control how the data in the map is accessed. Without the @MapKey annotation, the data in the map would be accessed by its column name, which can be difficult to remember.
MyBatis is often considered better than Hibernate because it is much simpler and easier to use. It is also more flexible, because it does not require you to use annotations or XML files to configure mapping. MyBatis is also more efficient, because it uses a dynamic SQL approach that only generates the SQL that is actually needed, rather than Hibernate’s approach of generating SQL for all possible queries.
Talk about the advantages and disadvantages of orm
“Advantages”1. Improve the development efficiency. Since ORM can automatically map fields and attributes between entity objects and tables in the database, we may not need a dedicated and huge data access layer. 2. ORM provides the mapping to the database, and it can get data from the database like an operation object without SQL coding directly.
“Shortcomings”Sacrificing the execution efficiency and fixed thinking mode of the program reduces the flexibility of development.
From the perspective of system structure, the system using ORM is generally a multi-layer system. If the system has more layers, the efficiency will be reduced. ORM is a completely object-oriented approach, and the object-oriented approach will also have a certain impact on performance.
When we develop a system, we usually have performance problems. The main performance problems are the incorrect algorithm and the incorrect use of database.
The code generated by ORM is not likely to write a very efficient algorithm, and it is more likely to be misused in database applications. It is mainly reflected in the extraction of persistent objects and the processing of data. If ORM is used, the programmer is likely to extract all the data into memory objects, and then filter and process them, which is easy to cause performance problems.
When persisting an object, ORM generally persistes all the attributes. Sometimes, this is undesirable. However, ORM is a tool, which can solve some repetitive and simple labor. This is undeniable. But we can’t expect tools to solve all problems once and for all. Some problems still need special treatment, but the parts that need special treatment should be few for most systems.
How many steps does JDBC have?
JDBC can be divided into six steps
If you are asked in the interview, just say the following three things:
——From the official website. I recommend that you answer according to the official.
The full name is object relational mapping. Object mapping relational database. Object relational mapping (ORM, or O / RM, or O / R mapping) is used to realize the data conversion between different types of systems in object-oriented programming language. In short, ORM is to use metadata to describe the mapping between objects and database to map objects in the program and relational database.
ORM provides another mode to realize persistence layer. It uses mapping metadata to describe the mapping of object relationship, so that ORM middleware can act as a bridge between business logic layer and database layer of any application.
FAQ
What is iBATIS framework?
Is iBATIS a ORM?
What is MyBatis framework?
Does MyBatis use JDBC?
