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WinVector / rqdatatable

Implement the rquery piped query algebra in R using data.table. Distributed under choice of GPL-2 or GPL-3 license.
https://winvector.github.io/rqdatatable/
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Implementation for MySqlConnection Needed #3

Closed lebensterben closed 5 years ago

lebensterben commented 5 years ago

Hi,

I was trying to join two tables from a remote MySQL database. Currently rquery can do this job well, but when I try to execute the same query with rqdatatable::ex_data_table(), it says

Error in ex_data_table.default(conn, optree) : 
  rqdatatable::ex_data_table() does not have an implementation for class:  MySQLConnection yet

Do you have plan to add MySQLConnection support in the near future?

Thanks

JohnMount commented 5 years ago

rqdatatable is only for in-memory data.frames. To work with MySQL you just use rquery. The command to run in rquery would be execute() or materialize(). Some database examples can be found here.

lebensterben commented 5 years ago

rqdatatable is only for in-memory data.frames. To work with MySQL you just use rquery. The command to run in rquery would be execute() or materialize(). Some database examples can be found here.

@JohnMount Thanks.

Just for clarification, if it's only for in-memory data.frames, then what's the advantage of using rqdatatable instead of data.table? As for rquery, is it just a query generator?

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JohnMount commented 5 years ago

rquery is "just a query generator." For in-memory rqdatatable is the same grammar as rquery, but has no advantage of data.table (which I am in fact a fan of).

lebensterben commented 5 years ago

rquery is "just a query generator." For in-memory rqdatatable is the same grammar as rquery, but has no advantage of data.table (which I am in fact a fan of).

@JohnMount thx

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