Error: query method parameters should either be a type that can be converted into a database column or a list / array that contains such type. you can consider adding a type adapter for this.

The error message “query method parameters should either be a type that can be converted into a database column or a list / array that contains such type. You can consider adding a type adapter for this.” typically occurs when you are trying to execute a database query with parameters that are not supported or not properly formatted.

To fix this error, you need to ensure that the parameters you pass to your query method are of a valid type or are properly formatted. Here are a few possible scenarios and their solutions:

1. Invalid parameter type: If you are passing a parameter that is not directly supported by the database column, you may need to convert it into a compatible type. For example, if you are trying to query a column of type “Timestamp” but passing a “Date” object as a parameter, you need to convert the “Date” object to a “Timestamp” object before executing the query.
   
   
public interface MyRepository extends JpaRepository<MyEntity, Long> {
    @Query("SELECT e FROM MyEntity e WHERE e.createDate >= :startDate")
    List<MyEntity> findByStartDate(@Param("startDate") Date startDate);
}

   
   In this case, you can use a type converter or adapter (e.g., using the @Temporal annotation in JPA) to convert the “Date” object to a “Timestamp” object.
2. Unsupported parameter type: If you are passing a parameter that is not directly supported by the database column and cannot be converted, you may need to change the data type of the column or find an alternate way to represent the data. For example, if you are trying to query a column that stores a custom data type (e.g., an enum), you might need to create a custom type adapter to convert the parameter into a format supported by the column.
   
   
public interface MyRepository extends JpaRepository<MyEntity, Long> {
    @Query("SELECT e FROM MyEntity e WHERE e.status = :status")
    List<MyEntity> findByStatus(@Param("status") MyStatusEnum status);
}

   
   In this case, you can create a custom type adapter for the MyStatusEnum to convert it into a format supported by the column. You can use frameworks like Gson or Jackson to provide the conversion logic.
3. Formatting issues: Ensure that the parameters you pass to the query method are properly formatted. For example, if you are passing a string parameter, make sure it is enclosed within quotation marks. Similarly, if you are passing a list or array parameter, ensure that it is properly formatted.
   
   
public interface MyRepository extends JpaRepository<MyEntity, Long> {
    @Query("SELECT e FROM MyEntity e WHERE e.name IN :names")
    List<MyEntity> findByNames(@Param("names") List<String> names);
}

   
   In this case, make sure that the list of names you pass as a parameter is properly formatted and contains valid values.

By addressing these issues, you should be able to fix the “query method parameters should either be a type that can be converted into a database column or a list/array that contains such type. You can consider adding a type adapter for this” error.