Retrieves data to a local Andromeda object

This function sends SQL to the server, and returns the results in a local Andromeda object

querySqlToAndromeda(
  connection,
  sql,
  andromeda,
  andromedaTableName,
  errorReportFile = file.path(getwd(), "errorReportSql.txt"),
  snakeCaseToCamelCase = FALSE,
  appendToTable = 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 sent.

andromeda

An open Andromeda object, for example as created using Andromeda::andromeda().

andromedaTableName

The name of the table in the local Andromeda object where the results of the query will be stored.

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.

appendToTable

If FALSE, any existing table in the Andromeda with the same name will be replaced with the new data. If TRUE, data will be appended to an existing table, assuming it has the exact same structure.

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.

Value

Invisibly returns the andromeda. The Andromeda object will have a table added with the query results.

Details

Retrieves data from the database server and stores it in a local Andromeda object. This allows very large data sets to be retrieved without running out of memory. 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.If a table with the same name already exists in the local Andromeda object it is replaced.

Examples

if (FALSE) {
andromeda <- Andromeda::andromeda()
connectionDetails <- createConnectionDetails(
  dbms = "postgresql",
  server = "localhost",
  user = "root",
  password = "blah",
  schema = "cdm_v4"
)
conn <- connect(connectionDetails)
querySqlToAndromeda(
  connection = conn,
  sql = "SELECT * FROM person;",
  andromeda = andromeda,
  andromedaTableName = "foo"
)
disconnect(conn)

andromeda$foo
}