Android Room subquery in FROM clause not working as expected - android-sqlite

Question

I tested my query using https://sqliteonline.com/ but cannot get it to work with Android Room and I cannot understand why (believe me I've tried). Why is the query in my DAO not working? On the other hand, I'm not sure this is the best way to achieve what I'm trying to do so please do tell me if I should change my approach completely.
Also, it's my first time posting a question, I apologize if I'm omitting something important.
I made a test database with sqliteonline and verified my query is working there. I'm using Android Room in my project, with the following lines in my build.gradle (app):
// Room components
implementation 'androidx.room:room-runtime:2.1.0-beta01'
annotationProcessor 'androidx.room:room-compiler:2.1.0-beta01'
androidTestImplementation 'androidx.room:room-testing:2.1.0-beta01'
The query that works in the testing environment:
SELECT *,
(SELECT COUNT(*) FROM groups WHERE parent_id=a.id) AS gCount,
(SELECT COUNT(*) FROM relays WHERE parent_id=a.id) AS rCount
FROM (SELECT DISTINCT * FROM worksites) a ;
The query in my DAO:
#Query("SELECT *, " +
"(SELECT COUNT(*) FROM relay_groups WHERE worksite_id=a.w_id) AS amountRelayGroups," +
"(SELECT COUNT(*) FROM relays_table WHERE worksite_id=a.w_id) AS amountRelays" +
"FROM (SELECT DISTINCT * FROM worksites_table) a")
LiveData<List<Worksites>> fetchAllWorksites();
My tables:
#Entity(tableName = "worksites_table")
public class Worksites {
#PrimaryKey(autoGenerate = true)
#ColumnInfo(name = "w_id")
private long worksite_id;
#NonNull
#ColumnInfo(name = "w_name")
private String worksiteName;
#ColumnInfo(name = "w_description")
private String worksiteDescription;
#Ignore
#ColumnInfo(name = "amountRelays")
private long amountRelays;
#Ignore
#ColumnInfo(name = "amountRelayGroups")
private long amountRelayGroups;
#Entity (tableName = "relay_groups",
foreignKeys = #ForeignKey(entity = Worksites.class,
parentColumns = "w_id",
childColumns = "worksite_id",
onDelete = CASCADE))
public class RelayGroups {
public RelayGroups(){
}
public RelayGroups(String name){
this.groupName = name;
}
#PrimaryKey(autoGenerate = true)
#ColumnInfo(name = "group_id")
private long group_id;
#NonNull
#ColumnInfo(name = "group_name")
private String groupName;
#ColumnInfo(name = "description")
private String description;
#NonNull
#ColumnInfo(name = "worksite_id")
private long worksiteId;
#Entity(tableName = "relays_table",
foreignKeys = #ForeignKey(entity = Worksites.class,
parentColumns = "w_id",
childColumns = "worksite_id",
onDelete = CASCADE))
public class Relays implements Parcelable {
#PrimaryKey(autoGenerate = true)
#ColumnInfo(name = "relay_id")
private long relayId;
#NonNull
#ColumnInfo(name = "relay_name")
private String relayName;
#NonNull
#ColumnInfo(name = "relay_number")
private String relayNumber;
#ColumnInfo(name = "relay_started")
private boolean relayOnOff;
#NonNull
#ColumnInfo(name = "relay_type")
private String relayType;
#ColumnInfo(name = "registered_master")
private boolean registeredMaster;
#ColumnInfo(name = "registered_user")
private boolean registeredUser;
#ColumnInfo(name = "security_code")
private String securityCode;
#ColumnInfo(name = "groups_string")
private String groupsString;
#NonNull
#ColumnInfo(name ="worksite_id")
private long worksiteId;
#ColumnInfo(name ="description")
private String relayDescription;
I'm trying to get rows with all columns from the table "worksites" AND a count of matching worksite_ids in "relay_groups" and "relays_table" -tables.
The Java compiler hits me with the following errors/warnings:
error: extraneous input '(' expecting {<EOF>, ';', K_ALTER, K_ANALYZE, K_ATTACH, K_BEGIN, K_COMMIT, K_CREATE, K_DELETE, K_DETACH, K_DROP, K_END, K_EXPLAIN, K_INSERT, K_PRAGMA, K_REINDEX, K_RELEASE, K_REPLACE, K_ROLLBACK, K_SAVEPOINT, K_SELECT, K_UPDATE, K_VACUUM, K_VALUES, K_WITH, UNEXPECTED_CHAR}
no viable alternative at input 'DISTINCT * FROM worksites_table)'
The query returns some columns [amountRelayGroups, amountRelays] which are not used by PACKAGE.Worksites. You can use #ColumnInfo annotation on the fields to specify the mapping. PACKAGE.Worksites has some fields [w_description] which are not returned by the query. If they are not supposed to be read from the result, you can mark them with #Ignore annotation. You can suppress this warning by annotating the method with #SuppressWarnings(RoomWarnings.CURSOR_MISMATCH). Columns returned by the query: w_name, w_id, amountRelayGroups, amountRelays. Fields in PACKAGE.Worksites: w_id, w_name, w_description.

Answer 1

I think you are missing a space before "FROM
it should be
#Query("SELECT *, " +
"(SELECT COUNT(*) FROM relay_groups WHERE worksite_id=a.w_id) AS amountRelayGroups," +
"(SELECT COUNT(*) FROM relays_table WHERE worksite_id=a.w_id) AS amountRelays" +
" FROM (SELECT DISTINCT * FROM worksites_table) a")