Support for Function Expressions in String Queries

[otaviojava]

Jakarta Query supports a variety of built-in functions via its grammar:

function_expression
    : 'ABS' '(' scalar_expression ')'
    | 'LENGTH' '(' scalar_expression ')'
    | 'LOWER' '(' scalar_expression ')'
    | 'UPPER' '(' scalar_expression ')'
    | 'LEFT' '(' scalar_expression ',' scalar_expression ')'
    | 'RIGHT' '(' scalar_expression ',' scalar_expression ')'

These expressions are valid in WHERE clauses of string-based queries.

🎯 Goal

Enable support in Eclipse JNoSQL for the above function_expression types when using Jakarta Query integration.

🔍 Examples

Support should include queries such as:

SELECT * FROM Customer WHERE LENGTH(name) > 5
SELECT * FROM Product WHERE LOWER(category) = 'electronics'
SELECT * FROM Book WHERE ABS(price) > 10
SELECT * FROM Name WHERE LEFT(name, 2) = 'Jo'
SELECT * FROM Name WHERE RIGHT(name, 1) = 'y'

✅ With Parameters

Queries with parameters must also be supported:

SELECT * FROM Customer WHERE LENGTH(:name) > :minLength
SELECT * FROM Product WHERE LOWER(:category) = 'electronics'
SELECT * FROM Customer WHERE LEFT(:name, :quantity) = 'Jo'

Java example:

template.query("SELECT * FROM Customer WHERE LEFT(:name, :len) = 'Jo'", Customer.class)
        .bind("name", "Johnathan")
        .bind("len", 2)
        .result();

✅ Tasks

• Enhance the Jakarta Query parser integration in Eclipse JNoSQL to support the above function_expression types.
• Ensure parameters (e.g., :name, :len) can be bound in function expressions.
• Add tests for each supported function (with and without parameters).
• Document usage examples in JNoSQL reference guides.

[otaviojava]

Given the lack of maturity in this option for NoSQL databases, I will close this issue for now.

jakartaee/nosql#204

[omatheusmesmo]

@otaviojava , Could you please reopen this issue? As discussed in jakartaee/nosql#223, we believe it warrants further attention.