sqlParseVariables: Parse interpolated variables from SQL.

In rstats-db/SQL: Safely Generate Common SQL Strings

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(con, sql, ...)

## S4 method for signature 'DBIConnection'
sqlParseVariables(con, sql, ...)

CommentSpec(start, end, endRequired)

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

sqlParseVariablesImpl(sql, quotes, comments)

Arguments

sql	SQL to parse (a character vector of length 1)
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(QuoteSpec("[", "]", "\\", FALSE)),
  list()
)

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

rstats-db/SQL documentation built on May 28, 2019, 3:35 a.m.