These pool method for DBI generics methods check out a connection
(with poolCheckout()), re-call the generic, then return the connection
to the pool (with poolReturn()).
See DBI-custom for DBI methods that do not work with pool objects.
Usage
# S4 method for class 'Pool'
dbDataType(dbObj, obj, ...)
# S4 method for class 'Pool,ANY'
dbGetQuery(conn, statement, ...)
# S4 method for class 'Pool,ANY'
dbExecute(conn, statement, ...)
# S4 method for class 'Pool,ANY'
dbListFields(conn, name, ...)
# S4 method for class 'Pool'
dbListTables(conn, ...)
# S4 method for class 'Pool'
dbListObjects(conn, prefix = NULL, ...)
# S4 method for class 'Pool,ANY'
dbReadTable(conn, name, ...)
# S4 method for class 'Pool,ANY'
dbWriteTable(conn, name, value, ...)
# S4 method for class 'Pool'
dbCreateTable(conn, name, fields, ..., row.names = NULL, temporary = FALSE)
# S4 method for class 'Pool'
dbAppendTable(conn, name, value, ..., row.names = NULL)
# S4 method for class 'Pool,ANY'
dbExistsTable(conn, name, ...)
# S4 method for class 'Pool,ANY'
dbRemoveTable(conn, name, ...)
# S4 method for class 'Pool'
dbIsReadOnly(dbObj, ...)
# S4 method for class 'Pool'
sqlData(con, value, row.names = NA, ...)
# S4 method for class 'Pool'
sqlCreateTable(con, table, fields, row.names = NA, temporary = FALSE, ...)
# S4 method for class 'Pool'
sqlAppendTable(con, table, values, row.names = NA, ...)
# S4 method for class 'Pool'
sqlInterpolate(conn, sql, ..., .dots = list())
# S4 method for class 'Pool'
sqlParseVariables(conn, sql, ...)
# S4 method for class 'Pool,ANY'
dbQuoteIdentifier(conn, x, ...)
# S4 method for class 'Pool'
dbUnquoteIdentifier(conn, x, ...)
# S4 method for class 'Pool'
dbQuoteLiteral(conn, x, ...)
# S4 method for class 'Pool,ANY'
dbQuoteString(conn, x, ...)
# S4 method for class 'Pool'
dbAppendTableArrow(conn, name, value, ...)
# S4 method for class 'Pool'
dbCreateTableArrow(conn, name, value, ..., temporary = FALSE)
# S4 method for class 'Pool'
dbGetQueryArrow(conn, statement, ...)
# S4 method for class 'Pool'
dbReadTableArrow(conn, name, ...)
# S4 method for class 'Pool'
dbSendQueryArrow(conn, statement, ...)
# S4 method for class 'Pool'
dbWriteTableArrow(conn, name, value, ...)Arguments
- dbObj
A DBI Driver][DBI::DBIDriver-class] or DBI Connection.
- obj
An R object whose SQL type we want to determine.
- ...
Other arguments passed on to methods.
- conn
- statement
a character string containing SQL.
- name
The table name, passed on to
dbQuoteIdentifier(). Options are:a character string with the unquoted DBMS table name, e.g.
"table_name",a call to
Id()with components to the fully qualified table name, e.g.Id(schema = "my_schema", table = "table_name")a call to
SQL()with the quoted and fully qualified table name given verbatim, e.g.SQL('"my_schema"."table_name"')
- prefix
A fully qualified path in the database's namespace, or
NULL. This argument will be processed withdbUnquoteIdentifier(). If given the method will return all objects accessible through this prefix.- value
A data.frame (or coercible to data.frame).
- fields
Either a character vector or a data frame.
A named character vector: Names are column names, values are types. Names are escaped with
dbQuoteIdentifier(). Field types are unescaped.A data frame: field types are generated using
dbDataType().- row.names
Must be
NULL.- temporary
If
TRUE, will generate a temporary table.- con
A database connection.
- table
The table name, passed on to
dbQuoteIdentifier(). Options are:a character string with the unquoted DBMS table name, e.g.
"table_name",a call to
Id()with components to the fully qualified table name, e.g.Id(schema = "my_schema", table = "table_name")a call to
SQL()with the quoted and fully qualified table name given verbatim, e.g.SQL('"my_schema"."table_name"')
- values
A data frame. Factors will be converted to character vectors. Character vectors will be escaped with
dbQuoteString().- sql
A SQL string containing variables to interpolate. Variables must start with a question mark and can be any valid R identifier, i.e. it must start with a letter or
., and be followed by a letter, digit,.or_.- .dots
A list of named arguments to interpolate.
- x
A character vector, SQL or Id object to quote as identifier.
Examples
mtcars1 <- mtcars[ c(1:16), ] # first half of the mtcars dataset
mtcars2 <- mtcars[-c(1:16), ] # second half of the mtcars dataset
pool <- dbPool(RSQLite::SQLite())
# write the mtcars1 table into the database
dbWriteTable(pool, "mtcars", mtcars1, row.names = TRUE)
# list the current tables in the database
dbListTables(pool)
#> [1] "mtcars"
# read the "mtcars" table from the database (only 16 rows)
dbReadTable(pool, "mtcars")
#> row_names mpg cyl disp hp drat wt qsec vs am gear
#> 1 Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4
#> 2 Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4
#> 3 Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4
#> 4 Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3
#> 5 Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3
#> 6 Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3
#> 7 Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3
#> 8 Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4
#> 9 Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4
#> 10 Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4
#> 11 Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4
#> 12 Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3
#> 13 Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3
#> 14 Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3
#> 15 Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3
#> 16 Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3
#> carb
#> 1 4
#> 2 4
#> 3 1
#> 4 1
#> 5 2
#> 6 1
#> 7 4
#> 8 2
#> 9 2
#> 10 4
#> 11 4
#> 12 3
#> 13 3
#> 14 3
#> 15 4
#> 16 4
# append mtcars2 to the "mtcars" table already in the database
dbWriteTable(pool, "mtcars", mtcars2, row.names = TRUE, append = TRUE)
# read the "mtcars" table from the database (all 32 rows)
dbReadTable(pool, "mtcars")
#> row_names mpg cyl disp hp drat wt qsec vs am gear
#> 1 Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4
#> 2 Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4
#> 3 Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4
#> 4 Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3
#> 5 Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3
#> 6 Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3
#> 7 Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3
#> 8 Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4
#> 9 Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4
#> 10 Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4
#> 11 Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4
#> 12 Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3
#> 13 Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3
#> 14 Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3
#> 15 Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3
#> 16 Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3
#> 17 Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3
#> 18 Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4
#> 19 Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4
#> 20 Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4
#> 21 Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3
#> 22 Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3
#> 23 AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3
#> 24 Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3
#> 25 Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3
#> 26 Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4
#> 27 Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5
#> 28 Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5
#> 29 Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5
#> 30 Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5
#> 31 Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5
#> 32 Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4
#> carb
#> 1 4
#> 2 4
#> 3 1
#> 4 1
#> 5 2
#> 6 1
#> 7 4
#> 8 2
#> 9 2
#> 10 4
#> 11 4
#> 12 3
#> 13 3
#> 14 3
#> 15 4
#> 16 4
#> 17 4
#> 18 1
#> 19 2
#> 20 1
#> 21 1
#> 22 2
#> 23 2
#> 24 4
#> 25 2
#> 26 1
#> 27 2
#> 28 2
#> 29 4
#> 30 6
#> 31 8
#> 32 2
# get the names of the columns in the databases's table
dbListFields(pool, "mtcars")
#> [1] "row_names" "mpg" "cyl" "disp" "hp"
#> [6] "drat" "wt" "qsec" "vs" "am"
#> [11] "gear" "carb"
# use dbExecute to change the "mpg" and "cyl" values of the 1st row
dbExecute(pool,
paste(
"UPDATE mtcars",
"SET mpg = '22.0', cyl = '10'",
"WHERE row_names = 'Mazda RX4'"
)
)
#> [1] 1
# read the 1st row of "mtcars" table to confirm the previous change
dbGetQuery(pool, "SELECT * FROM mtcars WHERE row_names = 'Mazda RX4'")
#> row_names mpg cyl disp hp drat wt qsec vs am gear carb
#> 1 Mazda RX4 22 10 160 110 3.9 2.62 16.46 0 1 4 4
# drop the "mtcars" table from the database
dbRemoveTable(pool, "mtcars")
# list the current tables in the database
dbListTables(pool)
#> character(0)
poolClose(pool)