dbt render macro 简单说明

dbt render macro 官方文档并没有说明，但是在一些三方adapter 中发现有使用到简单说明下

参考使用

{% materialization external, adapter="duckdb", supported_languages=['sql', 'python'] %}

  {%- set location = render(config.get('location', default=external_location(this, config))) -%})

  {%- set rendered_options = render_write_options(config) -%}

.....

内部处理

• context 定义

@contextmember

def render(self, string: str) -> str:

    return get_rendered(string, self._ctx, self.model)

• get_rendered 处理

可以看到内部实际上是一个jinja2 的处理

def get_rendered(

    string: str,

    ctx: Dict[str, Any],

    node=None,

    capture_macros: bool = False,

    native: bool = False,

) -> str:

    # performance optimization: if there are no jinja control characters in the

    # string, we can just return the input. Fall back to jinja if the type is

    # not a string or if native rendering is enabled (so '1' -> 1, etc...)

    # If this is desirable in the native env as well, we could handle the

    # native=True case by passing the input string to ast.literal_eval, like

    # the native renderer does.

    if not native and isinstance(string, str) and _HAS_RENDER_CHARS_PAT.search(string) is None:

        return string

    template = get_template(

        string,

        ctx,

        node,

        capture_macros=capture_macros,

        native=native,

    )

    return render_template(template, ctx, node)

说明

render macro 官方没有说明，但是从功能上看似乎是一个很强大的macro，可以实现macro 再调用处理,如下

{% set  location = "{{this}}" %}

{{log("render    info " ~ render(location),info=True) }}

select * from {{myref('pg','sensor')}}

参考资料

https://github.com/duckdb/dbt-duckdb