jinjasql-rs

WIP Rust port of the JinjaSQL Python extension for Jinja2, powered by minijinja.

Usage

The inclause and bind filters are the main attraction here, as they allow us to keep track of the variables injected into the SQL statement and stash them for passing into the client at query time via params.

let j = JinjaSqlBuilder::new().build();
let query_string = indoc! {"
select{% for col in columns %}
    {{ col }}{%- if not loop.last %},{% endif %}{% endfor %}
from
    (
    select {% for col in columns %}
    {{ col }}{%- if not loop.last %},{% endif %}{% endfor %} from {{ table_name | upper }}
    where sku in {{ skus | inclause }}
)a
where 
    tag in {{ tags | reverse | inclause }}
    and stock_date = {{ baz | bind }}
"};

let (res, params) = j
    .render_query(
        Some(query_string),
        None,
        context!(
            columns => vec!["apple", "lettuce", "lemon"],
            table_name => "orders.stock_data",
            tags => vec!["moldy", "sweet", "fresh"],
            skus => vec!["EE-001", "EA-001", "BA-001"],
            baz => "2022-01-01"
        ),
    )
    .unwrap();

returns:

select
    apple,
    lettuce,
    lemon
from
    (
    select 
    apple,
    lettuce,
    lemon from ORDERS.STOCK_DATA
    where sku in ($1, $2, $3)
)a
where 
    tag in ($4, $5, $6)
    and stock_date = $7

-- ["EE-001", "EA-001", "BA-001", "fresh", "sweet", "moldy", "2022-01-01"]

TODO

• alternate param styles
• automatic bind filtering (depends on the ability to modify the parser stream, a-la jinja2.Extension)
• benchmarks
• better state encapsulation
  • solved for now until a solution for mutable filter state stabilizes
• better tests
• publish to crates.io
  • docs
• python bindings?