# #设置,包括= FALSE --------------------------------------------------- knitr: opts_chunk美元集(崩溃= TRUE,发表评论 = "#>" ) ## ---- 负载,消息= FALSE, eval = TRUE ----------------------------------------- 图书馆(SQLDataFrame)图书馆(DBI) # #——构造函数 -------------------------------------------------------------- dbfile < -执行(“extdata / test.db”、包=“SQLDataFrame”)康涅狄格州< - DBI:: dbConnect (dbDriver(“SQLite”),dbname = dbfile) obj < SQLDataFrame(康涅狄格州=康涅狄格州,数据表=“状态”,是从=“状态”)obj ## ----------------------------------------------------------------------------- slotNames (obj)数据表(obj)是从(obj ) ## ----------------------------------------------------------------------------- tblData (obj ) ## ----------------------------------------------------------------------------- dbnrows (obj) dbconcatKey (obj ) ## ----------------------------------------------------------------------------- obj@indexes obj_sub < - obj[样本(5 3取代= TRUE), 2:3) obj_sub obj_sub@indexes相同(tblData (obj) tblData (obj_sub )) ## ----------------------------------------------------------------------------- obj_filter < - obj % > %过滤器(部门= =“南大西洋”&大小= =“介质”)obj_filter@indexes相同(tblData (obj) tblData (obj_filter)) obj_select < - obj % > %选择(部门、大小)obj_select@indexes相同(tblData (obj),tblData (obj_select )) ## ----------------------------------------------------------------------------- rnms < - ROWNAMES (obj) obj[示例(rnms 3 ), ] ## ----------------------------------------------------------------------------- 其中obj1 < - SQLDataFrame(康涅狄格州=康涅狄格州,数据表=“状态”,是从= c(“地区”、“人口”))ROWNAMES(其中obj1[1:10,])其中obj1 [c(“南:3615.0”、“西:365.0 "), ] ## ----------------------------------------------------------------------------- sessionInfo ()