README.md

In hxia/SqlRender4Impala: Rendering Parameterized SQL and Translation to Dialects

SqlRender

Introduction

This is an R package for rendering parameterized SQL, and translating it to different SQL dialects. SqlRender can also be used as a stand-alone Java library.

Features

• Supports a simple markup syntax for making SQL parameterized, and renders parameterized SQL (containing the markup syntax) to executable SQL
• The syntax supports defining default parameter values
• The syntax supports if-then-else structures
• Has functions for translating SQL from one dialect (Microsoft SQL Server) to other dialects (Oracle, PostgreSQL, Amazon RedShift)

Examples

This exampe shows the use of parameters, as well as SqlRender's {if} ? {then} : {else} syntax:

sql <- renderSql("SELECT * FROM @a; {@b != ''}?{USE @b;}", a = "my_table", b = "my_schema")$sql

will produce the variable sql containing this value:

"SELECT * FROM my_table; USE my_schema;"

subsequently running this code

sql <- translateSql(sql, "sql server", "oracle")$sql

will produce the variable sql containing this value:

"SELECT * FROM my_table; ALTER SESSION SET current_schema =  my_schema;"

Technology

The SqlRender package is an R package wrapped around a Java library. The rJava package is used as interface.

The Java library is available as a JAR file.

System Requirements

Running the package requires R with the package rJava installed. Also requires Java 1.6 or higher.

Dependencies

• There are no dependencies.

Getting Started

R package

Use these commands in R to download and install the SqlRender package:

install.packages("devtools")
library("devtools")
install_github("ohdsi/SqlRender")

Java library

You can fetch the JAR file in the inst/java folder of this repository, or use Maven:

1. First add the SqlRender repository so that maven can find and download the SqlRender artifact automatically:

<repositories>
    <repository>
        <id>ohdsi</id>
        <name>repo.ohdsi.org</name>
        <url>http://repo.ohdsi.org:8085/nexus/content/repositories/releases</url>
    </repository>
    <repository>
        <id>ohdsi.snapshots</id>
        <name>repo.ohdsi.org-snapshots</name>
        <url>http://repo.ohdsi.org:8085/nexus/content/repositories/snapshots</url>
        <releases>
            <enabled>false</enabled>
        </releases>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </repository>
</repositories>

2: Include the SqlRender dependency in your pom.xml

<dependency>
    <groupId>org.ohdsi.sql</groupId>
    <artifactId>SqlRender</artifactId>
    <version>1.0.0-SNAPSHOT</version>
</dependency>

Getting Involved

• Vignette: Using SqlRender
• Package manual: SqlRender manual
• Developer questions/comments/feedback: OHDSI Forum
• We use the GitHub issue tracker for all bugs/issues/enhancements

License

SqlRender is licensed under Apache License 2.0

Development

SqlRender is being developed in R Studio.

Development status

Stable. The code is actively being used in several projects.

Acknowledgements

• This project is supported in part through the National Science Foundation grant IIS 1251151.

hxia/SqlRender4Impala documentation built on May 17, 2019, 9:15 p.m.