This works as well! Thank you.
I ended up adding a .export_to_csv_file() to the end of Cliff's code and
re-importing the data to table3. The final version of this application
might see tens of thousands of lines, each with ~40 columns in each table.
Which way do you think would work better?
David
On Tuesday, April 9, 2013 10:12:08 AM UTC-4, Massimo Di Pierro wrote:
>
> If they fit in ram and have the same column names:
>
> rows = db(db.table1).select()
> rows = rows + db(db.table2).select()
> rows = rows + db(db.table3).select()
> rows = rows.sort(lambda row: row.col8) # optional
>
> On Monday, 8 April 2013 15:29:35 UTC-5, David S wrote:
>>
>> I have three tables, db.table1 db.table2 and db.table3. They are
>> identical except for the information stored in each. table3 is blank and
>> after running some code should contain the combination of the values in
>> table1 and table2.
>>
>> An example (<uuid> is generated by web2py_uuid()):
>>
>> db.table1:
>> col1 col2 col3 col4 col5 col6 col7 col8
>> 1 A Z x x <uuid>
>> 2 B Y x x <uuid>
>> 3 C X x x <uuid>
>> 4 D W x x <uuid>
>>
>> db.table2:
>> col1 col2 col3 col4 col5 col6 col7 col8
>> 1 A Z y y <uuid>
>> 2 B Y y y <uuid>
>> 3 C X y y <uuid>
>> 4 D W y y <uuid>
>>
>> After merging, db.table3 should look like this:
>>
>> db.table3:
>> col1 col2 col3 col4 col5 col6 col7 col8
>> 1 A Z x x y y <uuid>
>> 2 B Y x x y y <uuid>
>> 3 C X x x y y <uuid>
>> 4 D W x x y y <uuid>
>>
>> After some research, I found that exporting table1 and table2 to separate
>> .csv files and then importing them into table3 should be an easy way to do
>> this, however it does not seem to be working for me. Below is the code I've
>> tried to use:
>>
>> rows = db(db.table1).select()
>> rows.export_to_csv_file(open('table1.csv','wb'))
>> db.table3.import_from_csv_file(open('table1.csv','rb'),unique='col1')
>>
>> rows = db(db.table2).select()
>> rows.export_to_csv_file(open('table2.csv','wb'))
>> db.table3.import_from_csv_file(open('table2.csv','rb'),unique='col1')
>>
>> The problem I'm having is only the values from table2 are showing in
>> table3.
>>
>> I've also tried using a join like this:
>>
>> db(db.table1.col1 == db.table2.col1).select()
>>
>> But it creates something which looks like this:
>>
>> col1 col2 col3 col4 col5 col6 col7 col8 col1 col2 col3 col4 col5 col6
>> col7 col8
>> 1 A Z x x <uuid> 1 A Z y
>> y <uuid>
>> 2 B Y x x <uuid> 2 B Y y
>> y <uuid>
>> 3 C X x x <uuid> 3 C X y
>> y <uuid>
>> 4 D W x x <uuid> 4 D W y
>> y <uuid>
>>
>> Is there another way of doing the join which would produce table3 how I'd
>> like it formatted?
>>
>> Anyone have a suggestion or better way to do this?
>>
>> Thanks,
>> David
>>
>
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