Обсуждение: Re: querying from 3 tables

hi list.

i have 3 tables with the following columns:

table1: esourceid (primary key), brgyid, households
table2: brgyid (primary key), munprovid
table3: munprovid (primary key), geom

i am given the esourceid and i need to query the brgyid and the households of
a particular esourceid: query1="select brgyid, households from table1 where
esourceid=$esourceid;"

the resulting brgyid will then be used to query for the munprovid in table2:
query2="select munprovid from table2 where brgyid=(query1);"

the resulting munprovid will then be used to query for  the geom column:
"select geom from table3 where munprovid=(query2);"

my question is, how do i do this? any ideas?

> i am given the esourceid and i need to query the brgyid and the households
of
> a particular esourceid: query1="select brgyid, households from table1
where
> esourceid=$esourceid;"
>
> the resulting brgyid will then be used to query for the munprovid in
table2:
> query2="select munprovid from table2 where brgyid=(query1);"
>
> the resulting munprovid will then be used to query for  the geom column:
> "select geom from table3 where munprovid=(query2);"
>
> my question is, how do i do this? any ideas?

You can do this:

select geom from table3 where munprovid=(select munprovid from table2 where
brgyid=(select brgyid, households from table1 where esourceid=$esourceid));

Chris

What about the following:

select a.brgyd,a.households,b.munprovid,c.geom
from table1 a, table2 b, table3 c
where a.esourceid=$esourceid and
             a.brgyd=b.brgyd and
             b.munprovid=c.geom ;


Bye, Francesco

ryanne.cruz@up.edu.ph wrote:

>
> hi list.
>
> i have 3 tables with the following columns:
>
> table1: esourceid (primary key), brgyid, households
> table2: brgyid (primary key), munprovid
> table3: munprovid (primary key), geom
>
> i am given the esourceid and i need to query the brgyid and the households of
> a particular esourceid: query1="select brgyid, households from table1 where
> esourceid=$esourceid;"
>
> the resulting brgyid will then be used to query for the munprovid in table2:
> query2="select munprovid from table2 where brgyid=(query1);"
>
> the resulting munprovid will then be used to query for  the geom column:
> "select geom from table3 where munprovid=(query2);"
>
> my question is, how do i do this? any ideas?
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster

What about the following:

select a.brgyd,a.households,b.munprovid,c.geom
from table1 a, table2 b, table3 c
where a.esourceid=$esourceid and
             a.brgyd=b.brgyd and
             b.munprovid=c.geom ;


Bye, Francesco

ryanne.cruz@up.edu.ph wrote:

>
> hi list.
>
> i have 3 tables with the following columns:
>
> table1: esourceid (primary key), brgyid, households
> table2: brgyid (primary key), munprovid
> table3: munprovid (primary key), geom
>
> i am given the esourceid and i need to query the brgyid and the households of
> a particular esourceid: query1="select brgyid, households from table1 where
> esourceid=$esourceid;"
>
> the resulting brgyid will then be used to query for the munprovid in table2:
> query2="select munprovid from table2 where brgyid=(query1);"
>
> the resulting munprovid will then be used to query for  the geom column:
> "select geom from table3 where munprovid=(query2);"
>
> my question is, how do i do this? any ideas?
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster

Sorry ...... this is the rigth query

What about the following:

select a.brgyd,a.households,b.munprovid,c.geom
from table1 a, table2 b, table3 c
where a.esourceid=$esourceid and
             a.brgyd=b.brgyd and
             b.munprovid=c.munprovid ;


Bye, Francesco

ryanne.cruz@up.edu.ph wrote:

>
> hi list.
>
> i have 3 tables with the following columns:
>
> table1: esourceid (primary key), brgyid, households
> table2: brgyid (primary key), munprovid
> table3: munprovid (primary key), geom
>
> i am given the esourceid and i need to query the brgyid and the households of
> a particular esourceid: query1="select brgyid, households from table1 where
> esourceid=$esourceid;"
>
> the resulting brgyid will then be used to query for the munprovid in table2:
> query2="select munprovid from table2 where brgyid=(query1);"
>
> the resulting munprovid will then be used to query for  the geom column:
> "select geom from table3 where munprovid=(query2);"
>
> my question is, how do i do this? any ideas?
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster