Hello,
In lookml i have one explorer :
Example :
explore: toto{
join: tata{
type: left_outer
relationship: one_to_many
sql_on: ${toto.id} = ${tata.id} ;;
}
}
why in explorer when i select only one field1 from tata table the sql generaled use toto ? something like :
select filed1 from toto left join tata on toto.id = tata.id
or for me i just need this sql :
select field1 from tata
Thank you for your response.
Best regards
Best answer by Dawid
View original
+1
Because “toto” is the base view for the explore. The join is just that - something that joins to the base explore based on a key. The way Looker builds SQL is that it doesn’t change the base table even if you use a field only from a join.
Thanks you Dawid,
so if i have table1 join table2 and table2 join table3...and table9 join table10 and i want in explorer to see fields from table10 looker will generate all joins from table1 to table10 ?
because with a complex model with several tables, it may come back heavy when loading data. no ?
I wonder if it is good practice to use lookml ?
Thank you
+1
When you have a SQL like this:
SELECT
table_b.field_at
FROM table_a
LEFT JOIN table_b USING(some_id)
Then your base table is still table_a.
Looker creates the JOINs dynamically but the base is always the same. It will only generate JOINs it needs but the base needs to be there, so in your case it will generate table1 and table10
thank you so much
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