How to Perform the following query using Greendao ?

Question

I have 2 tables A and B.

Table A contains names and table B contains selected names.

Now I would like to perform the following query on these tables using greendao, Please let me know if it is possible and if it is not are there any alternatives (maybe a raw query).

select * 
from A inner join B
on A.nameid = B.nameid

Also, Table A columns: id, nameid, name
and Table B columns: id, nameid, name, rating

score 9 · Accepted Answer · edited May 23 '17 at 11:53

9

I think this might help. You can use the raw query as a fake join. And you get all you want in the Query object

Query query = ATableDao.queryBuilder().where(
new StringCondition("nameid IN " +
"(SELECT nameid FROM B_Table )").build();

Since "nameid" doesn't seems to be a unique identifier in your sample. I won't suggest to use Relations to solve this issue. If you are try to use Relations, you can find my previous answer here.

edited May 23 '17 at 11:53

Community

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answered Feb 07 '14 at 08:48

Nevin Chen

1,815
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You should use the TABLENAME and the Properties to avoid typos. – AlexS Feb 11 '14 at 13:57
@AlexS You are right XD. I just copy that from the document XD – Nevin Chen Feb 11 '14 at 16:27

score 2 · Answer 2 · answered Jun 25 '14 at 21:32

2

Try this:

List<ATableObj> listATableObj = ATableDao.queryRawCreate(", BTable BT 
WHERE BT.nameid = T.nameid").list();

answered Jun 25 '14 at 21:32

fabrizotus

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This is weird, this method does not exist. I am using GreenDao 1.2.0. Am I missing something ? – Leeeeeeelo Feb 23 '15 at 22:05
Try with GreenDao 1.3.0 – fabrizotus Feb 24 '15 at 22:23

score 1 · Answer 3 · answered Feb 07 '14 at 05:18

If you use greendao this works differntly:

Instead of your query you select rows from table a (or b) and if you need a field of b (or a) you call getB() (or getA()) to get the corresponding row of that table.

If you have rows in table a that have no match in table b and you have rows in table b that have no match in a and you onlly want to select everything that has matches uin both tables, you would have to do a raw query to filter the rows of a (or b).

can you give me an example of the raw query ? – Rushi Feb 07 '14 at 06:49 — Rushi, Feb 07 '14 at 06:49

How to Perform the following query using Greendao ?

3 Answers3