I cannot connect postgresql schema.table with dply

问题:

Im trying to connect postgres with dplyr functions

my_db <- src_postgres(dbname = 'mdb1252', user = "diego", password = "pass")
my_db
src:  postgres 9.2.5 [postgres@localhost:5432/mdb1252]
tbls: alf, alturas, asociad, atenmed, base, bfa_boys_p_exp, bfa_boys_z_exp,
  bfa_girls_p_exp, bfa_girls_z_exp, bres, c21200012012, c212000392011, c212000532011,
  c21200062012, c212006222012, c212007352012, c212012112013, c212012242012,
  c212012452012, c2222012242012, calles, cap, cap0110, casos_tbc_tr09, casos_tbctr09,
  casosvadela, catpo, cbcvl, cie09, cie10, cie103d, cie103dantigua, cie10c, cie9a,
  cie9mc, clasiarc, coalc, coddepto, codedades, codest, codlocaerbio, codprov, coheb,
  cohec, cohep, cohiv, coho09_20110909_m, coign, combl, comet, comp, comport, conev,
  conymad, copri, corci3cod, corci910, cores, corin, cotab, cutoi, cutto, def0307,......

but when I try to connect a tbl

my_tbl <- tbl(my_db, 'def0307')

Error in postgresqlExecStatement(conn, statement, ...) : 
  RS-DBI driver: (could not Retrieve the result : ERROR:  no existe la relación «def0307»
LINE 1: SELECT * FROM "def0307" WHERE 0=1;
                      ^
)

I think the problem is a schema issue because sql should be:

 SELECT * FROM mortalidad.def0307

I made my_tbl <- tbl(my_db, 'mortalidad.def0307');

my_tbl <- tbl(my_db, c('mortalidad','def0307')) without a solution.

Im having a lot of fun working with dplyr Im from SQL but I wish resolve that and trying dplyr skills.

Thanks in advance.

回答1:

Finally dplyr has the solution to this problem thanks to the latest version 0.7 recently announced by Hadley Wickham. The DBI and dbplyr libraries greatly simplified the connection between dplyr and PostgreSQL.

con <- DBI::dbConnect(RPostgreSQL::PostgreSQL(), 
host = "database.rstudio.com",
user = "hadley",
password = rstudioapi::askForPassword("Database password"))
tbl <- dplyr::tbl(con, dbplyr::in_schema('mortalidad','def0307'))

回答2:

You might want this,

db=src_postgres(dbname = 'mdb1252',  
               user = "diego", password = "pass", options="-c search_path=mortalidad")

回答3:

If anybody ends up here with the same problem, here is what works for me: (taken from @Diego's comment from Feb 6'14)

postgre_table <- function (src, schema, table) {
  paste('SELECT * FROM', paste(schema, table, sep = '.')) %>% 
    sql() %>% tbl(src = src)
}