DatabaseConnector (version 6.3.3)

querySql: Retrieve data to a data.frame

Description

This function sends SQL to the server, and returns the results.

Usage

querySql(
  connection,
  sql,
  errorReportFile = file.path(getwd(), "errorReportSql.txt"),
  snakeCaseToCamelCase = FALSE,
  integerAsNumeric = getOption("databaseConnectorIntegerAsNumeric", default = TRUE),
  integer64AsNumeric = getOption("databaseConnectorInteger64AsNumeric", default = TRUE)
)

Value

A data frame.

Arguments

connection

The connection to the database server created using either connect() or DBI::dbConnect().

sql

The SQL to be send.

errorReportFile

The file where an error report will be written if an error occurs. Defaults to 'errorReportSql.txt' in the current working directory.

snakeCaseToCamelCase

If true, field names are assumed to use snake_case, and are converted to camelCase.

integerAsNumeric

Logical: should 32-bit integers be converted to numeric (double) values? If FALSE 32-bit integers will be represented using R's native Integer class.

integer64AsNumeric

Logical: should 64-bit integers be converted to numeric (double) values? If FALSE 64-bit integers will be represented using bit64::integer64.

Details

This function sends the SQL to the server and retrieves the results. If an error occurs during SQL execution, this error is written to a file to facilitate debugging. Null values in the database are converted to NA values in R.

Examples

if (FALSE) {
connectionDetails <- createConnectionDetails(
  dbms = "postgresql",
  server = "localhost",
  user = "root",
  password = "blah",
  schema = "cdm_v4"
)
conn <- connect(connectionDetails)
count <- querySql(conn, "SELECT COUNT(*) FROM person")
disconnect(conn)
}