| sqliteSupport {RSQLite} | R Documentation |
These functions are the workhorses behind the RSQLite package, but users need not invoke these directly.
## SQLiteDriver-related
sqliteInitDriver(max.con=16, fetch.default.rec = 500, force.reload=FALSE)
sqliteDriverInfo(obj, what, ...)
sqliteDescribeDriver(obj, verbose = FALSE, ...)
sqliteCloseDriver(drv, ...)
## SQLiteConnection-related
sqliteNewConnection(drv, dbname, mode = 0, cache_size=NULL, synchronous=0)
sqliteConnectionInfo(obj, what, ...)
sqliteDescribeConnection(obj, verbose = FALSE, ...)
sqliteCloseConnection(con, ...)
## SQLiteResult-related
sqliteExecStatement(con, statement, limit)
sqliteFetch(res, n=0, ...)
sqliteQuickSQL(con, statement, ...)
sqliteResultInfo(obj, what, ...)
sqliteDescribeResult(obj, verbose = FALSE, ...)
sqliteCloseResult(res, ...)
## data mappings and convenience functions
sqliteDataType(obj, ...)
sqliteReadTable(con, name, row.names = "row_names", check.names = TRUE, ...)
sqliteImportFile(con, name, value, field.types, overwrite=FALSE,
append=FALSE, header, row.names, nrows=50, sep=",", eol="\n",
skip = 0, ...)
sqliteWriteTable(con, name, value, ...)
sqliteTableFields(con, name, ...)
max.con |
positive integer specifying maximum number of open connections. The default is 10. Note that since SQLite is embedded in R/S-Plus connections are simple, very efficient direct C calls. |
fetch.default.rec |
default number of rows to fetch (move to R/S-Plus). This default is
used in sqliteFetch.
The default is 500.
|
force.reload |
logical indicating whether to re-initialize the driver. This may be
useful if you want to change the defaults (e.g., fetch.default.rec).
Note that the driver is a singleton (subsequent inits just returned the
previously initialized driver, thus this argument).
|
obj |
any of the SQLite DBI objects (e.g., SQLiteConnection,
SQLiteResult).
|
what |
character vector of metadata to extract, e.g., "version", "statement", "isSelect". |
verbose |
logical controlling how much information to display.
Defaults to FALSE.
|
drv |
an SQLiteDriver object as produced by sqliteInit.
|
con |
an SQLiteConnection object as produced by sqliteNewConnection.
|
res |
an SQLiteResult object as produced by by sqliteExecStatement.
|
dbname |
character string with the SQLite database file name (SQLite, like Microsoft's Access, stores an entire database in one file). |
mode |
positive integer describing the mode for opening the database (SQLite's underlying API currently does not yet use it, but it is reserved for future functionality). The default is 0. |
cache_size |
positive integer to pass to the PRAGMA cache_size; this
changes the maximum number of disk pages that SQLite will hold in
memory (SQLite's default is 2000 pages).
|
synchronous |
values the PRAGMA synchronous flag, possible values are
0, 1, or 2 or the corresponding strings "OFF", "NORMAL", or "FULL".
The RSQLite package uses a default of 0 (OFF), although
SQLite's default is 2 (FULL) as of version 3.2.8.
Users have reported significant speed ups using sychronous="OFF",
and the SQLite documentation itself implies considerably improved
performance at the very modest risk of database corruption in the
unlikely case of the operating system (not the R application)
crashing.
|
force |
logical indicating whether to close a connection that has open
result sets. The default is FALSE.
|
statement |
character string holding SQL statements. |
limit |
integer specifying maximum number or rows to fetch. The default is -1 (fetch all rows). |
n |
number of rows to fetch from the given result set. A value of -1
indicates to retrieve all the rows. The default of 0 specifies
to extract whatever the fetch.default.rec was specified
during driver initialization sqliteInit.
|
name |
character vector of names (table names, fields, keywords). |
value |
a data.frame. |
field.types |
a list specifying the mapping from R/S-Plus fields in the data.frame
value to SQL data types. The default is
sapply(value,SQLDataType), see SQLiteSQLType.
|
row.names |
a logical specifying whether to prepend the value data.frame
row names or not. The default is TRUE.
|
check.names |
a logical specifying whether to convert DBMS field names into
legal S names. Default is TRUE.
|
overwrite |
logical indicating whether to replace the table name with
the contents of the data.frame value.
The defauls is FALSE.
|
append |
logical indicating whether to append value to the existing
table name.
|
header |
logical, does the input file have a header line? Default is the
same heuristic used by read.table, i.e., TRUE if the first
line has one fewer column that the second line.
|
nrows |
number of lines to rows to import using read.table from the
input file to create the proper table definition. Default is 50.
|
sep |
field separator character. |
eol |
end-of-line separator. |
skip |
number of lines to skip before reading data in the input file. |
... |
placeholder for future use. |
sqliteInitDriver returns an SQLiteDriver object.
sqliteDriverInfo returns a list of name-value metadata pairs.
sqliteDescribeDriver returns NULL (displays the object's
metadata).
sqliteCloseDriver returns a logical indicating whether the
operation succeeded or not.
sqliteNewConnection returns an SQLiteConnection object.
sqliteConnectionInforeturns a list of name-value metadata pairs.
sqliteDescribeConnection returns NULL (displays the
object's metadata).
sqliteCloseConnection returns a logical indicating whether the
operation succeeded or not.
sqliteExecStatement returns an SQLiteResult object.
sqliteFetch returns a data.frame.
sqliteQuickSQL returns either a data.frame if the statement is
a select-like or NULL otherwise.
sqliteDescribeResult returns NULL (displays the object's
metadata).
sqliteCloseResult returns a logical indicating whether the
operation succeeded or not.
sqliteReadTable returns a data.frame with the contents of the
DBMS table.
sqliteWriteTable returns a logical indicating whether the
operation succeeded or not.
sqliteImportFile returns a logical indicating whether the
operation succeeded or not.
sqliteTableFields returns a character vector with the
table name field names.
sqliteDataType retuns a character string with the closest
SQL data type. Note that SQLite is typeless, so this is mostly for
creating table that are compatible across RDBMS.
sqliteResultInfo returns a list of name-value metadata pairs.
.SQLitePkgName (currently "RSQLite"),
.SQLitePkgVersion (the R package version),
.SQLitePkgRCS (the RCS revision),
.SQLitecle.NA.string (character that SQLite uses to
denote NULL on input),
.conflicts.OK.