Is there a way to select all columns for a SELECT statement with JOINs without breaking the entity mapping?

Question

I have a application_user table with a corresponding UserEntity record. Additionally, I have a user_meta_data table with a UserMetaDataEntity record as a 1:1 relation to the user.

@Table("application_user")
record UserEntity(@Id @Nullable Long id,
                  // more columns
                  @Nullable
                  UserMetaDataEntity metaData
) {
// (...)
}

Currently, I need to directly write SQL queries, as I have some complex queries at hand that can't be modeled easily via function names. In these queries, I need to explicitly select all columns

@Query("""
        SELECT application_user.ID AS ID, user_meta_data.phoneNumber AS USERMETADATA_PHONE_NUMBER
        FROM application_user
        INNER JOIN user_meta_data ON user_meta_data.user_id = application_user.id
""")
Stream<UserEntity> streamUsersWithMetaData();

But I want to avoid explicitly defining column names, as my actual entities have many columns. I would prefer calling SELECT * FROM application_user INNER JOIN ... but this doesn't work, as Spring Data JDBC expects the column names to be prefixed with the joined table name.

Is there a way to define custom SQL queries without needing to define all columns in the SELECT statement?

score 1 · Accepted Answer · answered Nov 30 '21 at 07:26

You can't use SELECT * but there are at least two ways you can minimise the pain.

Either you define a static final String containing the list of columns and concatenate them with the rest of the query.

Alternatively you can specify a RowMapper doing the mapping. It could wrap the ResultSet and forward the call to the original EntityRowMapper

Is there a way to select all columns for a SELECT statement with JOINs without breaking the entity mapping?

1 Answers1