## ----setup, include = FALSE------------------------------------------------ knitr::opts_chunk$set( collapse = TRUE, comment = "#>" ) ## ----Load, message=FALSE, eval = TRUE-------------------------------------- library(SQLDataFrame) library(DBI) ## ----constructor----------------------------------------------------------- dbfile <- system.file("extdata/test.db", package = "SQLDataFrame") conn <- DBI::dbConnect(dbDriver("SQLite"), dbname = dbfile) obj <- SQLDataFrame( conn = conn, dbtable = "state", dbkey = "state") obj ## -------------------------------------------------------------------------- slotNames(obj) dbtable(obj) dbkey(obj) ## -------------------------------------------------------------------------- tblData(obj) ## -------------------------------------------------------------------------- dbnrows(obj) dbconcatKey(obj) ## -------------------------------------------------------------------------- obj@indexes obj_sub <- obj[sample(5, 3, replace = TRUE), 2:3] obj_sub obj_sub@indexes identical(tblData(obj), tblData(obj_sub)) ## -------------------------------------------------------------------------- obj_filter <- obj %>% filter(division == "South Atlantic" & size == "medium") obj_filter@indexes identical(tblData(obj), tblData(obj_filter)) obj_select <- obj %>% select(division, size) obj_select@indexes identical(tblData(obj), tblData(obj_select)) ## -------------------------------------------------------------------------- rnms <- ROWNAMES(obj) obj[sample(rnms, 3), ] ## -------------------------------------------------------------------------- obj1 <- SQLDataFrame(conn = conn, dbtable = "state", dbkey = c("region", "population")) ROWNAMES(obj1[1:10,]) obj1[c("South:3615.0", "West:365.0"), ] ## -------------------------------------------------------------------------- sessionInfo()