Tag: jpql

select new (JPQL Constructor Expression) in jpa/hibernate causes “lazy” loading for each row

Recently I found no obvious behaviour when using ‘select new/constructor expression’ in jpa/hibernate. It uses kind of lazy loading for each entity in each row in result set what is not efficient. Test example First case we issue a query using select new technique: This issues one query to fetch only ids of e1 and e2 and then more queries

JPQL issue updating records

java jpa jpql

Trying to update a record in a database but getting this error: Code below is responsible for inserting it Im not sure if there is a type issue with propId being a Long or if i have written the SQL paths wrong or both. Answer You’re trying to execute an SQL query as JPQL. There are a couple options to

JPQL query that give me the highest value

eclipselink java jpa jpql sql

I’m trying to do a JPQL query that give me the highest PK of the PKs in my table (https://drive.google.com/file/d/1_kaklkKdCbhT0-byqCtz6HgfluKKp8J-/view?usp=sharing). Here is my query : The error says that the syntax of my query is wrong. Can someone please help me ? Thank you for your help 🙂 Answer Thank you for your comments ! It allowed me to solve

Does JPQL support the use of a boolean result in another expression?

hibernate java jpa jpql spring-data

I am trying to write a query to back a search API. Specifically for a flag searchDrafts – if the flag is true I have to get rows with status DRAFT and else I have to get all rows that have any status other than DRAFT. In regular SQL, the below query works fine: However, a similar thing in JPQL

Showing a specific JSON response for my GET endpoint

hibernate java jpa jpql spring-boot

I have a many-to-many relationship between Department and Employee I have already done a mapping for the GET endpoint which returns a list of departments that contain Employees, this is the request: http://localhost:8080/api/departments/1/employees, and this is the response I get: This is the code that gets the job done: Department Repository Imp Employee Service Impl Department Controller Now what I

Spring Data JPA sorting by property without hardcoding

java jpql spring spring-boot spring-data-jpa

I have entity that has several fields: I want to have code which is capable to sort by foo and sort by bar depending on the request. I know that there is tool that could be used like this: But it seems like this approach is not perfect because field names are hardcoded and in the case that some field

How to handle an error when database returns null value for one of the columns in the table

java jpql spring spring-boot spring-data

I’m using Java and Spring Boot with JPQL to access the data. I’m getting the below error because hourlyRate is null in the database: Caused by: org.hibernate.QueryException: could not instantiate class [com.example.model.response.school.Employee] from tuple. I still would like to be able to get the data from the database even when that column has null value in the database and send

How use generic entity name in JPQL

java jpa jpql spring-data-jpa

I have three tables with same column name and types, what changes is just the table name. Example: | TABLE1 | TABLE2 | TABLE3 | | —— | —— | ——- | | ID | ID | ID | | NAME | NAME | NAME | | FOO | FOO | FOO | | BAR | BAR | BAR |

Passing a query as a query parameter in JPQL Native Query

java jpa jpql sql

I’m trying to pass a query as a string parameter in another JPQL native query. So the resulting query would be something like the query below that returns me a value but what I’m getting in return is only the string of :query parameter and not the result of the executed complete query. Answer Create an interface for a custom

How to check UUID null value in JPQL?

hibernate java jpa jpql spring

I am using JPA/Hibernate. So I wanna to do nullCheck in JPQL, but when I do that it does not determine dataType. JPQL Query: EXCEPTION: Caused by: org.postgresql.util.PSQLException: ERROR: could not determine data type of parameter $1 at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2532) at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2267) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:312) at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:448) at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:369) at org.postgresql.jdbc.PgPreparedStatement.executeWithFlags(PgPreparedStatement.java:153) at org.postgresql.jdbc.PgPreparedStatement.executeQuery(PgPreparedStatement.java:103) at jdk.internal.reflect.GeneratedMethodAccessor582.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.apache.tomcat.jdbc.pool.StatementFacade$StatementProxy.invoke(StatementFacade.java:114)