DBI-wrap: DBI methods (simple wrappers)

In pool: Object Pooling

DBI methods (simple wrappers)

Description

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()).

Usage

## S4 method for signature 'Pool'
dbDataType(dbObj, obj, ...)

## S4 method for signature 'Pool,ANY'
dbGetQuery(conn, statement, ...)

## S4 method for signature 'Pool,ANY'
dbExecute(conn, statement, ...)

## S4 method for signature 'Pool,ANY'
dbListFields(conn, name, ...)

## S4 method for signature 'Pool'
dbListTables(conn, ...)

## S4 method for signature 'Pool'
dbListObjects(conn, prefix = NULL, ...)

## S4 method for signature 'Pool,ANY'
dbReadTable(conn, name, ...)

## S4 method for signature 'Pool,ANY'
dbWriteTable(conn, name, value, ...)

## S4 method for signature 'Pool'
dbCreateTable(conn, name, fields, ..., row.names = NULL, temporary = FALSE)

## S4 method for signature 'Pool'
dbAppendTable(conn, name, value, ..., row.names = NULL)

## S4 method for signature 'Pool,ANY'
dbExistsTable(conn, name, ...)

## S4 method for signature 'Pool,ANY'
dbRemoveTable(conn, name, ...)

## S4 method for signature 'Pool'
dbIsReadOnly(dbObj, ...)

## S4 method for signature 'Pool'
sqlData(con, value, row.names = NA, ...)

## S4 method for signature 'Pool'
sqlCreateTable(con, table, fields, row.names = NA, temporary = FALSE, ...)

## S4 method for signature 'Pool'
sqlAppendTable(con, table, values, row.names = NA, ...)

## S4 method for signature 'Pool'
sqlInterpolate(conn, sql, ..., .dots = list())

## S4 method for signature 'Pool'
sqlParseVariables(conn, sql, ...)

## S4 method for signature 'Pool,ANY'
dbQuoteIdentifier(conn, x, ...)

## S4 method for signature 'Pool'
dbUnquoteIdentifier(conn, x, ...)

## S4 method for signature 'Pool'
dbQuoteLiteral(conn, x, ...)

## S4 method for signature 'Pool,ANY'
dbQuoteString(conn, x, ...)

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)

# read the "mtcars" table from the database (only 16 rows)
dbReadTable(pool, "mtcars")

# 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")

# get the names of the columns in the databases's table
dbListFields(pool, "mtcars")

# 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'"
  )
)

# read the 1st row of "mtcars" table to confirm the previous change
dbGetQuery(pool, "SELECT * FROM mtcars WHERE row_names = 'Mazda RX4'")

# drop the "mtcars" table from the database
dbRemoveTable(pool, "mtcars")

# list the current tables in the database
dbListTables(pool)

poolClose(pool)

pool documentation built on March 7, 2023, 6:49 p.m.