dbApply-methods {RMySQL} | R Documentation

## Apply R/S-Plus functions to remote groups of DBMS rows (experimental)

### Description

Applies R/S-Plus functions to groups of remote DBMS rows without bringing an entire result set all at once. The result set is expected to be sorted by the grouping field.

### Methods

res
  a MySQL result set (see `dbSendQuery`).
...
  any additional arguments to be passed to `FUN`.

### References

See the Database Interface definition document `DBI.pdf` in the base directory of this package or http://stat.bell-labs.com/RS-DBI.

### See Also

`MySQL` `mysqlDBApply` `dbSendQuery` `fetch`

### Examples

    ## Not run:
    ## compute quanitiles for each network agent
    con <- dbConnect(MySQL(), group="vitalAnalysis")
    rs <- dbSendQuery(con,
                 "select Agent, ip_addr, DATA from pseudo_data order by Agent")
    out <- dbApply(rs, INDEX = "Agent",
            FUN = function(x, grp) quantile(x$DATA, names=FALSE))
    ## End(Not run)

[Package RMySQL version 0.6-0 Index]