| sqlFetch {RODBC} | R Documentation |
Read a table of an ODBC database into a data frame.
sqlFetch(channel, sqtable, ..., colnames = FALSE, rownames = TRUE) sqlFetchMore(channel, ..., colnames = FALSE, rownames = TRUE)
channel |
connection handle returned by odbcConnect. |
sqtable |
a database table name accessible from the connected dsn. This should be either a character string or a character vector of length 1. |
... |
additional arguments to be passed to
sqlQuery or sqlGetResults. See Details. |
colnames |
logical: retrieve column names from first row of table?
(For use when sqlSave(colnames = TRUE) was used.) |
rownames |
either logical or character.
If logical, retrieve row names from the first column
(rownames) in the table? If character, the column name to
retrieve them. |
sqlFetch retrieves the the entire contents of the table
sqtable. Rownames and column names are restored as indicated
(assuming that they have been placed in the table by the corresponding
arguments to sqlSave).
sqlFetchMore will retrieve further results from the query
(provided there has been no other ODBC query on that channel in the
meantime).
It tries to cope with the peculiar way the Excel ODBC driver handles table names, and to quote Access table names which contain spaces.
Useful additional parameters to pass to sqlQuery or
sqlGetResults include
max:nullstring:SQL_NULL_DATA character items from the database:
default NA.na.strings:NA when reading character data: default "NA".as.is:sqlGetResults.dec:rows_at_time:
A data frame on success, or a character or numeric error code (see
sqlQuery).
If the table name desired is not a valid SQL name (alphanumeric plus
_), use sqlQuery with whatever quoting mechanism
your DBMS vendor provides (e.g. [ ] on Microsoft products and
backticks on recent versions of MySQL).
Michael Lapsley and Brian Ripley
sqlSave, sqlQuery,
odbcConnect, odbcGetInfo
## Not run:
channel <- odbcConnect("test")
sqlSave(channel, USArrests)
sqlFetch(channel, "USArrests") # get the lot
sqlFetch(channel, "USArrests", max=20)
sqlFetchMore(channel, max=20)
sqlFetchMore(channel) # get the rest
sqlDrop(channel, "USArrests")
close(channel)
## End(Not run)