[Ballerina Community Call] Language Integrated Queries
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The document provides an overview of Language Integrated Queries (LIQ) presented by Chiran Fernando, focusing on its capabilities within the Ballerina programming language for efficient data processing and querying. It includes examples of SQL commands for generating reports and demonstrates how LIQ simplifies query syntax with various operators. Future developments aim to enhance grouping, aggregation support, and unbounded event stream capabilities.
![Query Expressions
int[] nums = [1, 2, 3, 4, 5];
int sum = 0;
error? result = from int i in nums
do {
sum += i;
};
int[] nums = [1, 2, 3, 4, 5];
int[] evenNums = from int i in nums
where i % 2 == 0
select i;
Query Actions](https://image.slidesharecdn.com/ballerinacommunitycall-september2021-210928034707/85/Ballerina-Community-Call-Language-Integrated-Queries-10-320.jpg)
[Ballerina Community Call] Language Integrated Queries
- 1. Using Language Integrated Queries Chiran Fernando Associate Technical Lead, WSO2
- 2. During this session ❖ Introduction to language integrated queries ❖ Ease of data processing using integrated queries ❖ Demonstration of a real-world example ❖ Future plans of language integrated queries
- 3. Let’s create a “California revenue Q3” report. You can create this report by writing one line of SQL: SELECT SUM(Value_USD) AS California_Revenue_Q3 FROM Transactions WHERE Location = 'California' AND DATEPART(q, Date) = 3 AND YEAR(Date) = 2021;
- 4. If we wanted to break it down by location the SQL would be as follows: SELECT Location, SUM(Value_USD) AS Revenue_Q3 FROM Transactions WHERE DATEPART(q, Date) = 3 AND YEAR(Date) = 2021 GROUP BY Location ORDER BY Location;
- 5. What if we can bring query capabilities directly into Ballerina language?
- 7. ● Brings query capabilities directly into the Ballerina language. ● It has a uniform query syntax which can be applied on different list comprehensions. ● By using query syntax, you can perform filtering, ordering operations on data collections with a minimum of code.
- 8. Ease of data processing using integrated queries
- 9. Anatomy of a Language Integrated Query ○ From ○ Optional operators (join, where, let, order by, limit) ○ Action(do, select)
- 10. Query Expressions int[] nums = [1, 2, 3, 4, 5]; int sum = 0; error? result = from int i in nums do { sum += i; }; int[] nums = [1, 2, 3, 4, 5]; int[] evenNums = from int i in nums where i % 2 == 0 select i; Query Actions
- 11. Query Clauses ○ From ○ Where ○ Let ○ Join ○ Limit ○ Order by ○ Select
- 14. Demonstration of a real-world example
- 15. Future plans for Language Integrated Queries
- 16. ● Support for grouping and aggregation ● Extend support for unbounded event streams
- 17. Open Discussion