This document describes RagnarDB SQL, an object-oriented SQL querying plugin for Gosu. The goals are to interpret data definition files to create types, add object-oriented functionality to those types, and support SQL query building. It discusses parsing DDL files to extract table and column information to generate types at compile time. It also covers building SQL queries using the generated types, including select, join, where, and other clauses to enable complex queries in an object-oriented way similar to libraries like jOOQ. Future work includes additional data types, transactions, caching, and resolving N+1 query issues.

1. RagnarDB SQL
KAI LU AND PATRICK JENNINGS

2. Project Goals
 Create an Object Oriented SQL Querying plugin in Gosu
 Interpret Data Definition Files
 Create Types based on these descriptions
 Add Object Oriented Functionality to these types
 Add support similar to that in more common languages
 Compare to Java Object Oriented Querying Library (jOOQ)

3. Parsing
 Recursive descent parsing
 Top Down Approach
 Testing for correctness via ANTLR
 Lexing code into Tokens

4. Parsing
DDL CreateTable
ColumnDefinition
Constraint
 Extracting data we care about
 A DDL File contains many tables
 Tables contain many Column Definitions and many Constraints

5. Type system Metaprogramming
 Information from the parser is loaded into the Gosu Typeloader at
Compile time
 Types for each table are created
 Methods related to tables can also be invoked statically
 We use this to support custom query building

6. Query Construction
 At this point, our new classes still don’t do much
 So we added support for construction of SQL queries
 Queries can be called off of constructed types statically
 Insert instances of types into database
 SQLConstraint Class describes clauses in SQL statements

7. Query Functionality
 Select Statements
 Specify Rows returned
 Join Statements, On statements
 Recursive Support for multiple Joins
 Where Statements
 Is In Constraints
 SQL SubQueries
 Is Equal to / Greater, Less than, etc
 Is Like
 Boolean Logic For multiple constraints
 Order By
 Limit Clauses

8. Fine-grain control for complex
queries
 SELECT name, phone, email, address FROM customers AS
contactInfo WHERE country = ‘US’;
 WITH RECURSIVE destinations(city, country) AS (
SELECT city, country FROM connections WHERE start = ‘Foster City’
UNION ALL
SELECT city, country FROM connections WHERE start = city
)
SELECT * FROM destinations
 SELECT game FROM ign WHERE rating > (SELECT rating FROM ign
WHERE game = ‘Tales Of Symphonia’)

9. SQL Files are now Gosu Types
 PresentationQuery1.sql:
SELECT * FROM Contacts WHERE Name = ‘Kai Lu’;
->
var kais = MyQuery.execute()
 for(kai in kais){
print(kai.Name)
}
->
Kai Lu
ID Name Email Age
1 Patrick Jennings pjennings 19
2 Kai Lu klu 19
3 Luca Boasso lboasso ??
4 Kyle Moore kmoore ??
Contacts

10. Query Execution:

11. Parameterization
 @variableName:variableType exposes a parameter of type
variableType, called variableName to the plugin

12. Applications

13. Moving Forward
 Full Set of Data Types (arrays, date/time, XML)
 Transactions and multiple queries
 Connection management
 Cache management
 Error Handling
 Resolving the N+1 queries problem