querySql: Retrieve data to a data.frame

In DatabaseConnector: Connecting to Various Database Platforms

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)
)

Arguments

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

Value

A data frame.

Examples

## Not run: 
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)

## End(Not run)

DatabaseConnector documentation built on May 29, 2024, 6:14 a.m.