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Why does jpa one-way one-to-many association thymeleaf or stack overflow?
there is a set collection of tag classes in the user class;
maintain relationships only from the user class, one-to-many
@ OneToMany
@JoinTable(name="shuo_tag",
inverseJoinColumns=@JoinColumn(name="tag_id"),
jo...
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Springjpa and thymeleaf work together, the two classes cascade reference each other, HTML pages use objects, error report, is the bug of thymeleaf?
https: github.com thymeleaf .
I use jpa, to cascade the two classes through annotations. in the html page, when you get the object of any class through the thymeleaf tag, it will appear .
java.lang.StackOverflowError: null at sun.reflect.misc.Refl...
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Use springdatajpa,hibernate to cascade two classes. Why do the two tables share the primary key?
one class
@Entity
public class Shuo{
@Id
@GeneratedValue
private int id;
private String title;
private Date date;
String content;
@ManyToOne(cascade = CascadeType.REFRESH)
@JoinColumn(name = "user_id")
private User user;
:
@OneT...
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How does SpringDataJpa increase the table id of oracle by itself?
anyone who has used oracle knows that the self-increasing id, of oracle is usually implemented by sequence.
I only marked @ Id, on the entity and did not mark it to other additional comments. I thought there would be an error in save, but it actually ...
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Jpa entity class design
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...
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How do I insert data into JoinTable?
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...
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How to set the query interceptor of mongotemplate in spring data jpa
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. ...
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Save selective updates in Spring Data JPA
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 ...
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The problem of Spring Data Jpa Framework Custom query statement returning Custom 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...
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All lazy loads are triggered after the spring-data-jpa table entity is serialized.
< 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...
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How can spring data jpa query only some of the fields and not return all of them?
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...
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Spring JPA query results are multiple, but the return value is one, and the program does not report an error.
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...
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The insert method in SpringDataJPA is written like insertSelective in MyBatis?
[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...
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How to batch values with springData @ query
@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?
...
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SpringDataJpa stored procedure call
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...
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Java implements mongodb multi-condition query. It is best to take the request parameters dynamically.
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 ...
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The problem of creating tables in JPA
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....
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How do you add comments when JPA creates a table in an postgresql database?
mysql is @ Column (name = "name ", columnDefinition = "varchar (100) comment comment ) what does postgresql do? ...
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The save method is used in spring data jpa to save the object. Why is the object association table data returned by the method empty?
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...
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Why does spring data jpa get inconsistent results from executing the find method after executing the save method and the find method executing the find method without executing the save method?
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. ...
