通道正则表达式中找不到sqlfetch表

Question

I am trying to find fetch multiple Access files in which the table I need has a different name each time.

Example :

• in Access file 1, table name is "base1"
• in Access file 2, table name is "base2"
• etc.

I tried the following function which will be later used within a map function to fetch all Access files from my directory:

fetch <- function (x) { y <- odbcConnectAccess2007(x) sqlFetch(y,"^base.$") odbcCloseAll() }

R does not seem to like regular expressions on sqlfetch since I get the following message :

Error in odbcTableExists(channel, sqtable) : '^base.$': table not found on channel

Please note that this works perfectly when I use "base1" as sqltable instead of "^base.$"

Can you help me please ?

Answer 1

I have found the solution to this problem :

    fetch <- function (x) {
      y <- odbcConnectAccess2007(x)
      find_table_name <-
        str_extract(sqlTables(y)$TABLE_NAME, "^(base.*)$") %>%
        na.omit
      table_result <- sqlFetch(y, find_table_name[1])
      return(table_result)
      odbcCloseAll()

}