dbt config macro 简单说明

dbt 不少资源类型都支持config macro 的使用，可以进行灵活的配置管理

参考使用

• 配置
  模型的执行物化策略

{{ config(

    materialized="<materialization_name>",

    sql_header="<string>"

) }}

快照的

{{ config(

    target_schema="<string>",

    target_database="<string>",

    unique_key="<column_name_or_expression>",

    strategy="timestamp" | "check",

    updated_at="<column_name>",

    check_cols=["<column_name>"] | "all"

) }}

• 获取config

{% materialization incremental, default -%}

  {%- set unique_key = config.get('unique_key') -%}

  ...

• 提供的方法
  get，require，

内部处理

实际上就是一个类，实现了一些方法

• 参考配置

class Config(Protocol):

    def __init__(self, model, context_config: Optional[ContextConfig]):

        ...

 

# 这个是解析的，当然还有不少其他的实现

# Implementation of "config(..)" calls in models

class ParseConfigObject(Config):

    def __init__(self, model, context_config: Optional[ContextConfig]):

        self.model = model

        self.context_config = context_config

 

    def _transform_config(self, config):

        for oldkey in ("pre_hook", "post_hook"):

            if oldkey in config:

                newkey = oldkey.replace("_", "-")

                if newkey in config:

                    raise ConflictingConfigKeysError(oldkey, newkey, node=self.model)

                config[newkey] = config.pop(oldkey)

        return config

 

    def __call__(self, *args, **kwargs):

        if len(args) == 1 and len(kwargs) == 0:

            opts = args[0]

        elif len(args) == 0 and len(kwargs) > 0:

            opts = kwargs

        else:

            raise InlineModelConfigError(node=self.model)

 

        opts = self._transform_config(opts)

 

        # it's ok to have a parse context with no context config, but you must

        # not call it!

        if self.context_config is None:

            raise DbtRuntimeError("At parse time, did not receive a context config")

        self.context_config.add_config_call(opts)

        return ""

 

    def set(self, name, value):

        return self.__call__({name: value})

 

    def require(self, name, validator=None):

        return ""

 

    def get(self, name, default=None, validator=None):

        return ""

 

    def persist_relation_docs(self) -> bool:

        return False

 

    def persist_column_docs(self) -> bool:

        return False

• 上下文处理
  render_with_context 会使用_context_for ，_context_for会调用generate_parser_model_context 会使用到config

def generate_parser_model_context(

    model: ManifestNode,

    config: RuntimeConfig,

    manifest: Manifest,

    context_config: ContextConfig,

) -> Dict[str, Any]:

    # The __init__ method of ModelContext also initializes

    # a ManifestContext object which creates a MacroNamespaceBuilder

    # which adds every macro in the Manifest.

    ctx = ModelContext(model, config, manifest, ParseProvider(), context_config)

    # The 'to_dict' method in ManifestContext moves all of the macro names

    # in the macro 'namespace' up to top level keys

    return ctx.to_dict()

说明

以上是关于dbt config的简单说明，对于详细使用可以参考官方文档

参考资料

https://docs.getdbt.com/reference/data-test-configs
https://docs.getdbt.com/reference/dbt-jinja-functions/config