sql.template: sql.template - lightweight SQL templating engine

In decisionpatterns/sql.template: Light-weight, mustache-based SQL templating

Description

sql.template is a simple, mustache-based SQL templating library. It allows writing syntactically valid SQL that can execute as-is and simultaneously support injection of values programattically before sending the query for execution. It has three main functions

• substitution using whisker templates

• tags that allow for unmasking/uncommenting of SQL templating code

• read SQL from any connection-type object such as a file.

The package was designed so that the developers could share SQL code between developers from a shared or forked repository. It is very amenable to use with any of the R piping libraries.

References

http://en.wikipedia.org/wiki/Mustache_(template_system)
http://mustache.github
https://github.com/edwindj/whisker

See Also

sql
sqlutils: https://github.com/jbryer/sqlutils for an alternative approach

Examples

sql = "
SELECT
  *
FROM
  {{table}}
WHERE
  1 == 1
--fn: and FIRST_NAME = '{{first_name}}' /*ln: and LAST_NAME = '{{last_name}}'*/
"

replacement <- list( table = "pres", first_name = "Barack", last_name = "Obama" )

# COMPARE THE FOLLOWING:

sql_render( sql, replacement, render=FALSE, strip.comments = FALSE )
sql_render( sql, replacement )      # render
sql_render( sql, replacement, "fn" ) # render 'fn' tags
sql_render( sql, replacement, c("fn","ln") ) # render 'fn' tags

decisionpatterns/sql.template documentation built on July 6, 2020, 8:41 a.m.