render.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/RenderSql.R
\name{render}
\alias{render}
\title{Render SQL code based on parameterized SQL and parameter values}
\usage{
render(sql, warnOnMissingParameters = TRUE, ...)
}
\arguments{
\item{sql}{The parameterized SQL}

\item{warnOnMissingParameters}{Should a warning be raised when parameters provided to this
function do not appear in the parameterized SQL that is being
rendered? By default, this is TRUE.}

\item{...}{Parameter values}
}
\value{
A character string containing the rendered SQL.
}
\description{
\code{render} Renders SQL code based on parameterized SQL and parameter values.
}
\details{
This function takes parameterized SQL and a list of parameter values and renders the SQL that can
be send to the server. Parameterization syntax: \describe{ \item{@parameterName}{Parameters are
indicated using a @ prefix, and are replaced with the actual values provided in the render call.}
\item{\{DEFAULT @parameterName = parameterValue\}}{Default values for parameters can be defined
using curly and the DEFAULT keyword.} \item{\{if\}?\{then\}:\{else\}}{The if-then-else pattern is
used to turn on or off blocks of SQL code.} }
}
\examples{
render("SELECT * FROM @a;", a = "myTable")
render("SELECT * FROM @a {@b}?{WHERE x = 1};", a = "myTable", b = "true")
render("SELECT * FROM @a {@b == ''}?{WHERE x = 1}:{ORDER BY x};", a = "myTable", b = "true")
render("SELECT * FROM @a {@b != ''}?{WHERE @b = 1};", a = "myTable", b = "y")
render("SELECT * FROM @a {1 IN (@c)}?{WHERE @b = 1};",
  a = "myTable",
  b = "y",
  c = c(1, 2, 3, 4)
)
render("{DEFAULT @b = \"someField\"}SELECT * FROM @a {@b != ''}?{WHERE @b = 1};",
  a = "myTable"
)
render("SELECT * FROM @a {@a == 'myTable' & @b != 'x'}?{WHERE @b = 1};",
  a = "myTable",
  b = "y"
)
render(
  sql = "SELECT * FROM @a;",
  warnOnMissingParameters = FALSE,
  a = "myTable",
  b = "missingParameter"
)
}