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R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
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Type 'demo()' for some demos, 'help()' for on-line help, or
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>
> ## dbWriteTable test
> ##
> ## Assumes that
> ## a) PostgreSQL is running, and
> ## b) the current user can connect
> ## both of which are not viable for release but suitable while we test
> ##
> ## Dirk Eddelbuettel, 10 Sep 2009
>
> ## only run this if this env.var is set correctly
> if (Sys.getenv("POSTGRES_USER") != "" & Sys.getenv("POSTGRES_HOST") != "" & Sys.getenv("POSTGRES_DATABASE") != "") {
+
+ ## try to load our module and abort if this fails
+ stopifnot(require(RPostgreSQL))
+
+ ## load the PostgresSQL driver
+ drv <- dbDriver("PostgreSQL")
+
+ ## connect to the default db
+ con <- dbConnect(drv,
+ user=Sys.getenv("POSTGRES_USER"),
+ password=Sys.getenv("POSTGRES_PASSWD"),
+ host=Sys.getenv("POSTGRES_HOST"),
+ dbname=Sys.getenv("POSTGRES_DATABASE"),
+ port=ifelse((p<-Sys.getenv("POSTGRES_PORT"))!="", p, 5432))
+
+
+ # create a table
+ res <- dbGetQuery(con, "CREATE TABLE aa (pk integer primary key, v1 float not null, v2 float)" )
+
+ ## run a simple query and show the query result
+ res <- dbGetQuery(con, "INSERT INTO aa VALUES(3, 2, NULL)" )
+ res <- dbSendQuery(con, "select pk, v1, v2, v1+v2 from aa")
+ cat("dbColumnInfo\n")
+ print(dbColumnInfo(res))
+ print(dbColumnInfo(res))
+ cat("SELECT result\n")
+ df <- fetch(res, n=-1)
+ print(df)
+
+ ## cleanup
+ cat("Removing \"AA\"\n")
+ dbRemoveTable(con, "aa")
+ ## and disconnect
+ dbDisconnect(con)
+ }
Loading required package: RPostgreSQL
Loading required package: DBI
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "aa_pkey" for table "aa"
dbColumnInfo
name Sclass type len precision scale nullOK
1 pk integer INTEGER 4 -1 -1 FALSE
2 v1 double FLOAT8 8 -1 -1 FALSE
3 v2 double FLOAT8 8 -1 -1 TRUE
4 ?column? double FLOAT8 8 -1 -1 NA
name Sclass type len precision scale nullOK
1 pk integer INTEGER 4 -1 -1 FALSE
2 v1 double FLOAT8 8 -1 -1 FALSE
3 v2 double FLOAT8 8 -1 -1 TRUE
4 ?column? double FLOAT8 8 -1 -1 NA
SELECT result
pk v1 v2 ?column?
1 3 2 NA NA
Removing "AA"
[1] TRUE
>
> proc.time()
user system elapsed
0.446 0.027 0.524
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