the following error occurred when saving data using Spring DataJPA today: Exception in thread "main " org.hibernate.TransientObjectException: object references an unsaved transient instance save the transient instance before flushing: com.edurt.core...
after adding spring-boot-starter-data-jpa to your springboot project, when you unit test your repository with junit. There will be a lot of when starting the container through junit test case. The error of [Xlint:cantFindType] [AppClassLoader@xxxx] e...
novice to java, this may be a simple question for a veteran, but it really beats me as a novice to PHP. Recently, I am changing the springmvc framework used by a java project. Some of the query statements are as follows: public Predicate toPredicate(Ro...
has not been solved yet. I found a similar problem on https: stackoverflow.com que... on stackoverflow. I tried it myself and found that it could not filter the subresult set, but only parent. The filtered parent brought out all the sub-objects, . @En...
I opened the sql log, and found that the find method was executed after the save was executed, but not the sql. if find is executed directly, sql will be executed Why is this? what is the principle? there is no explanation on the official website. ...
I use the save method to save the object and get the object returned by the save method. The data of the joined object is empty when I save, I set the id of the associated beComment I thought I could return the beComment data completely when I re...
mysql is @ Column (name = "name ", columnDefinition = "varchar (100) comment comment ) what does postgresql do? ...
entity 1 inherits another entity 2. Entity 2 is a public entity with id,createDate and other common attributes, so entity 1 does not need to write these fields, but the table cannot be built, and an error is reported: Error starting ApplicationContext....
query conditions are composed of String and List, such as: (List < String > id, String location, String status,.) The exact number of fields in the parameter is not certain. There may be more than one . how to implement this situation? you d better ...
how does SpringDataJpa call a stored procedure without an OUT parameter through Repository? this is how my stored procedure is defined @Entity @NamedStoredProcedureQuery( name = "Markets.nearById", procedureName = "near...
@Modifying @Query(value = "insert into role_account (role_id,account_id) values ", nativeQuery = true) Integer insertUserRealtion (Long roleId, List<Long> userIds); as above, how to express after values? ...
[actual phenomenon] long-term use of MyBatis, tools using Mybatis (Mybatis Generator generic Mapper), can have methods like insertSelective (E). is actually mapped as follows: SQL (many fields have default values, but only part of the value is neede...
public interface UserRepository extends MongoRepository<User, Long> { User findByUsername(String username); } the above code uses the function of Spring JPA to find users according to their names, but multiple data can be queried in the databa...
suppose I create a new user with four fields, id, user name, password, and address. how does spring data jpa query only the username and password fields? (the actual developed table has more than 20 fields, and it takes 12 seconds for a query to return...
< H2 > demand < H2 > what I want to do is to trigger (.size) lazily load all the data of the associated table when needed, do not load the data of the associated table when not needed, and do whatever I want. < H2 > question < H2 > my table entity...
1. Due to the need to query the two code,name fields in the entity table, Baidu said that it can customize the query entity class, such as: public class Entity implements Serializable(){ String code ; String name ; ... public Entity (St...
in the use of Spring Data JPA, we often use the save method instead of updating. Doing so updates all fields, even the empty fields in the object, resulting in data loss. Although, JPA provides my own way to write SQL, but for updates, if I only want to ...
how to set the query intercepting query for mongotemplate in spring data jpa, and then modify the query statement before submitting the query. Just like the interceptor in hibernate. Now you need to intercept all MongoDBtemplate query requests. ...
Code first: entity class: @Entity @Table(name = "joinTable_a") public class JoinTableA { @Id @GeneratedValue private long id; private String name; @OneToOne @JoinTable(name = "join_a2b", joinColumns = @JoinColumn(n...
I am a novice in database. Recently, when using spring-data-jpa, I encountered the problem that I could not design entity classes according to the Emurr model, so I asked a question. Emurr model is shown in the following figure: consider Company a...