I am trying to do a regexp match between 2 datasets and get a merge of the datasets as if it were a join query. Here's the query that I have run on postgres and would like to find help in FME to do it.
WITH g as (select name from gname where feature_code = 'ADM2'),p as (select "NAME" FROM "NAMES" WHERE "PLACE_ID" IN (SELECT "PLACE_ID" FROM "PLACES" WHERE "TYPE" = 'X')) select g.name,p."NAME" from g join p on exists (select * from regexp_matches(g.name,p."NAME"))
Hi @raghunaren, since you have the query already, you can execute it with the SQLCreator or SQLExecutor transformer. I think it's the quickest way.
Hi @raghunaren, since you have the query already, you can execute it with the SQLCreator or SQLExecutor transformer. I think it's the quickest way.
I did try the inlinequerier but it seems i can't use the query as it is. Inlinequerier throws syntax errors while trying to execute this query. The reason I stuck to this query was that the query plan in this case was such that it executes faster than something like this.
select g.name, p."NAME" FROM gname g join "NAMES" p on exists(select * from regexp_matches(g.name,p."NAME") WHERE g.feat_code = 'ADM2' AND p."ID" IN (SELECT "ID" FROM "PLACES" WHERE "TYPE" = 'X'))
Sorry I should been more precise and elaborate in my question in the first place.
@raghunaren, I assumed that the two tables ("gname" and "NAMES") are belonging to the same database schema, i.e. the query you posted can be executed on PostgreSQL. If so, the SQLCreator or SQLExecutor could execute the query directly and outputs the resulting records.
If the tables are read from two different database schemas, the InlineQuerier may be a good choice. The InlineQuerier creates a temporary SQLite database internally and then executes a query on the database. However, SQLite doesn't support regex pattern matching by default unfortunately.
If your requirement is to just determine if g.name contains p.NAME, you can use the like operator. This is a simplified example to do that.
select g.name, p.NAME
from gname as g inner join NAMES as p
on g.name like '%'||p.NAME||'%'
Otherwise, a possible way is to perform CROSS JOIN with the InlineQuerier and then filter the resulting records by the StringSearcher with the regular expression (i.e. the value of NAME). This approach may take a long time because the cross join generates N x N records, but the StringSearcher definitely performs regex pattern matching for every combination of g.name and p.NAME
select g.name, p.NAME
from gname as g cross join NAMES as p
@raghunaren, I assumed that the two tables ("gname" and "NAMES") are belonging to the same database schema, i.e. the query you posted can be executed on PostgreSQL. If so, the SQLCreator or SQLExecutor could execute the query directly and outputs the resulting records.
If the tables are read from two different database schemas, the InlineQuerier may be a good choice. The InlineQuerier creates a temporary SQLite database internally and then executes a query on the database. However, SQLite doesn't support regex pattern matching by default unfortunately.
If your requirement is to just determine if g.name contains p.NAME, you can use the like operator. This is a simplified example to do that.
select g.name, p.NAME
from gname as g inner join NAMES as p
on g.name like '%'||p.NAME||'%'
Otherwise, a possible way is to perform CROSS JOIN with the InlineQuerier and then filter the resulting records by the StringSearcher with the regular expression (i.e. the value of NAME). This approach may take a long time because the cross join generates N x N records, but the StringSearcher definitely performs regex pattern matching for every combination of g.name and p.NAME
select g.name, p.NAME
from gname as g cross join NAMES as p
+15@raghunaren
if they are from not merged and unreferenced ports.
Then just merge them unconditionaly and then use regexp.
For instance, as you are just looking for names from a table in another table, just use a stringsearcher set to egexp (if needed).
If you need word matches use wordboundaries, in fme word boundaries are \\m ...\\M.
@raghunaren
if they are from not merged and unreferenced ports.
Then just merge them unconditionaly and then use regexp.
For instance, as you are just looking for names from a table in another table, just use a stringsearcher set to egexp (if needed).
If you need word matches use wordboundaries, in fme word boundaries are \\m ...\\M.
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