Create result sets

Creating result sets using DBI::dbSendQuery() (and by extension using DBI::dbGetQuery()) mostly follows DBI specification. One way where adbi deviates from DBI mechanisms is how the bigint setting is not only per connection, but the per-connection setting can be overridden on a result set basis. As default, the connection setting is applied, but passing one of the accepted values as bigint when creating a result set will subsequently use that setting for all fetches using this result set.

Usage

# S4 method for class 'AdbiConnection'
dbSendQueryArrow(
  conn,
  statement,
  ...,
  params = NULL,
  immediate = NULL,
  bigint = NULL
)

# S4 method for class 'AdbiConnection,character'
dbSendQuery(
  conn,
  statement,
  ...,
  params = NULL,
  immediate = NULL,
  bigint = NULL
)

# S4 method for class 'AdbiConnection,character'
dbSendStatement(
  conn,
  statement,
  ...,
  params = NULL,
  immediate = NULL,
  bigint = NULL
)

Arguments

conn

A DBI::DBIConnection object, as returned by DBI::dbConnect().

statement

a character string containing SQL.

...

Other parameters passed on to methods.

params

Optional query parameters (forwarded to DBI::dbBind())

immediate

Use TRUE for direct execution, FALSE to bind parameters, or NULL to inspect placeholders when the driver supports it.

bigint

The R type that 64-bit integer types should be mapped to, default is chosen according to the connection setting. See dbConnect() for the accepted values.

Value

An S4 class AdbiResult (inheriting from DBI::DBIResult).

Details

Multiple open result sets per connection are supported and support can be disabled by setting options(adbi.allow_multiple_results = FALSE). If not enabled, creating a new result will finalize potential other results and throw a warning.

If parameter metadata is unavailable, bind before fetching when parameters are needed. Without metadata, adbi does not check the number or names of the parameters, so a mismatch is reported only if the driver checks for it, possibly not until the statement is executed.

Without metadata, adbi cannot tell whether a statement sent with immediate = NULL has placeholders, so such a statement runs only once it is bound or DBI::dbGetRowsAffected() is called, as DBI::dbExecute() does. Pass immediate = TRUE for a statement without placeholders to run when it is sent. For an unbound statement sent with immediate = FALSE, DBI::dbGetRowsAffected() returns NA.

See also

adbi-driver

Examples

if (requireNamespace("adbcsqlite")) {
  library(DBI)
  con <- dbConnect(adbi::adbi(pkg = "adbcsqlite"), uri = ":memory:")
  dbWriteTable(con, "swiss", swiss)
  str(
    dbGetQuery(con, "SELECT Examination from swiss WHERE Agriculture < 30")
  )
  str(
    dbGetQuery(con, "SELECT Examination from swiss WHERE Agriculture < 30",
      bigint = "numeric")
  )
  dbDisconnect(con)
}
#> 'data.frame':	10 obs. of  1 variable:
#>  $ Examination: int  15 26 31 25 29 22 35 25 37 22
#> 'data.frame':	10 obs. of  1 variable:
#>  $ Examination: num  15 26 31 25 29 22 35 25 37 22