R: Parse interpolated variables from SQL.

sqlParseVariables {DBI}

R Documentation

Parse interpolated variables from SQL.

Description

If you're implementing a backend that uses non-ANSI quoting or commenting rules, you'll need to implement a method for sqlParseVariables that calls sqlParseVariablesImpl with the appropriate quote and comment specifications.

Usage

sqlParseVariables(conn, sql, ...)

sqlCommentSpec(start, end, endRequired)

sqlQuoteSpec(start, end, escape = "", doubleEscape = TRUE)

sqlParseVariablesImpl(sql, quotes, comments)

Arguments

`sql`	SQL to parse (a character string)
`start, end`	Start and end characters for quotes and comments
`endRequired`	Is the ending character of a comment required?
`escape`	What character can be used to escape quoting characters? Defaults to `""`, i.e. nothing.
`doubleEscape`	Can quoting characters be escaped by doubling them? Defaults to `TRUE`.
`quotes`	A list of `QuoteSpec` calls defining the quoting specification.
`comments`	A list of `CommentSpec` calls defining the commenting specification.

Examples

# Use [] for quoting and no comments
sqlParseVariablesImpl("[?a]",
  list(sqlQuoteSpec("[", "]", "\\", FALSE)),
  list()
)

# Standard quotes, use # for commenting
sqlParseVariablesImpl("# ?a\n?b",
  list(sqlQuoteSpec("'", "'"), sqlQuoteSpec('"', '"')),
  list(sqlCommentSpec("#", "\n", FALSE))
)

[Package DBI version 0.7 Index]