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Add order_by argument to get_column_values (#349)
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Claire Carroll authored and clrcrl committed May 19, 2021
1 parent 52bcb37 commit c02c009
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42 changes: 36 additions & 6 deletions CHANGELOG.md
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@@ -1,22 +1,52 @@
# dbt-utils v0.7.0 (unreleased)
## Breaking changes

### get_column_values
The order of (optional) arguments has changed in the `get_column_values` macro.

Before:
```jinja
{% macro get_column_values(table, column, order_by='count(*) desc', max_records=none, default=none) -%}
...
{% endmacro %}
```

After:
```jinja
{% macro get_column_values(table, column, max_records=none, default=none) -%}
...
{% endmacro %}
```
If you were relying on the position to match up your optional arguments, this may be a breaking change — in general, we recommend that you explicitly declare any optional arguments (if not all of your arguments!)
```
-- before: This works on previous version of dbt-utils, but on 0.7.0, the `50` would be passed through as the `order_by` argument
{% set payment_methods = dbt_utils.get_column_values(
ref('stg_payments'),
'payment_method',
50
) %}
-- after
{% set payment_methods = dbt_utils.get_column_values(
ref('stg_payments'),
'payment_method',
max_records=50
) %}
```

## Features
* Add new argument, `order_by`, to `get_column_values` (code originally in [#289](https://github.com/fishtown-analytics/dbt-utils/pull/289/) from [@clausherther](https://github.com/clausherther), merged via [#349](https://github.com/fishtown-analytics/dbt-utils/pull/349/))

## Fixes


## Under the hood

# dbt-utils v0.6.5
## Features
* Add new `accepted_range` test ([#276](https://github.com/fishtown-analytics/dbt-utils/pull/276) [@joellabes](https://github.com/joellabes))
* Make `expression_is_true` work as a column test (code originally in [#226](https://github.com/fishtown-analytics/dbt-utils/pull/226/) from [@elliottohara](https://github.com/elliottohara), merged via [#313](https://github.com/fishtown-analytics/dbt-utils/pull/313/))
* Add new schema test, `not_accepted_values` ([#284](https://github.com/fishtown-analytics/dbt-utils/pull/284) [@JavierMonton](https://github.com/JavierMonton))
* Support a new argument, `zero_length_range_allowed` in the `mutually_exclusive_ranges` test ([#307](https://github.com/fishtown-analytics/dbt-utils/pull/307) [@zemekeneng](https://github.com/zemekeneng))
* Add new schema test, `sequential_values` ([#318](https://github.com/fishtown-analytics/dbt-utils/pull/318), inspired by [@hundredwatt](https://github.com/hundredwatt))
* Support `quarter` in the `postgres__last_day` macro ([#333](https://github.com/fishtown-analytics/dbt-utils/pull/333/files) [@seunghanhong](https://github.com/seunghanhong))
* Add new argument, `unit`, to `haversine_distance` ([#340](https://github.com/fishtown-analytics/dbt-utils/pull/340) [@bastienboutonnet](https://github.com/bastienboutonnet))
* Add new schema test, `fewer_rows_than` (code originally in [#221](https://github.com/fishtown-analytics/dbt-utils/pull/230/) from [@dmarts](https://github.com/dmarts), merged via [#343](https://github.com/fishtown-analytics/dbt-utils/pull/343/))


## Fixes
* Handle booleans gracefully in the unpivot macro ([#305](https://github.com/fishtown-analytics/dbt-utils/pull/305) [@avishalom](https://github.com/avishalom))
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34 changes: 30 additions & 4 deletions README.md
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Expand Up @@ -510,24 +510,50 @@ These macros run a query and return the results of the query as objects. They ar


#### get_column_values ([source](macros/sql/get_column_values.sql))
This macro returns the unique values for a column in a given [relation](https://docs.getdbt.com/docs/writing-code-in-dbt/class-reference/#relation).
It takes an options `default` argument for compiling when the relation does not already exist.
This macro returns the unique values for a column in a given [relation](https://docs.getdbt.com/docs/writing-code-in-dbt/class-reference/#relation) as an array.

Arguments:
- `table` (required): a [Relation](https://docs.getdbt.com/reference/dbt-classes#relation) (a `ref` or `source`) that contains the list of columns you wish to select from
- `column` (required): The name of the column you wish to find the column values of
- `order_by` (optional, default=`'count(*) desc'`): How the results should be ordered. The default is to order by `count(*) desc`, i.e. decreasing frequency. Setting this as `'my_column'` will sort alphabetically, while `'min(created_at)'` will sort by when thevalue was first observed.
- `max_records` (optional, default=`none`): The maximum number of column values you want to return
- `default` (optional, default=`[]`): The results this macro should return if the relation has not yet been created (and therefore has no column values).


**Usage:**
```sql
-- Returns a list of the payment_methods in the stg_payments model_
{% set payment_methods = dbt_utils.get_column_values(table=ref('stg_payments'), column='payment_method') %}
{% for state in states %}
{% for payment_method in payment_methods %}
...
{% endfor %}
...
```

#### get_relations_by_pattern ([source](macros/sql/get_relations_by_pattern.sql))
```sql
-- Returns the list sorted alphabetically
{% set payment_methods = dbt_utils.get_column_values(
table=ref('stg_payments'),
column='payment_method',
order_by='payment_method'
) %}
```

```sql
-- Returns the list sorted my most recently observed
{% set payment_methods = dbt_utils.get_column_values(
table=ref('stg_payments'),
column='payment_method',
order_by='max(created_at) desc',
max_records=50,
default=['bank_transfer', 'coupon', 'credit_card']
%}
...
```

#### get_relations_by_pattern ([source](macros/sql/get_relations_by_pattern.sql))
Returns a list of [Relations](https://docs.getdbt.com/docs/writing-code-in-dbt/class-reference/#relation)
that match a given schema- or table-name pattern.

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2 changes: 1 addition & 1 deletion integration_tests/models/sql/test_get_column_values.sql
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@@ -1,5 +1,5 @@

{% set columns = dbt_utils.get_column_values(ref('data_get_column_values'), 'field', default = []) %}
{% set columns = dbt_utils.get_column_values(ref('data_get_column_values'), 'field', default=[], order_by="field") %}


{% if target.type == 'snowflake' %}
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24 changes: 6 additions & 18 deletions macros/sql/get_column_values.sql
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@@ -1,26 +1,13 @@
{#
This macro fetches the unique values for `column` in the table `table`

Arguments:
table: A model `ref`, or a schema.table string for the table to query (Required)
column: The column to query for unique values
max_records: If provided, the maximum number of unique records to return (default: none)

Returns:
A list of distinct values for the specified columns
#}

{% macro get_column_values(table, column, max_records=none, default=none) -%}
{{ return(adapter.dispatch('get_column_values', packages = dbt_utils._get_utils_namespaces())(table, column, max_records, default)) }}
{% macro get_column_values(table, column, order_by='count(*) desc', max_records=none, default=none) -%}
{{ return(adapter.dispatch('get_column_values', packages = dbt_utils._get_utils_namespaces())(table, column, order_by, max_records, default)) }}
{% endmacro %}

{% macro default__get_column_values(table, column, max_records=none, default=none) -%}
{% macro default__get_column_values(table, column, order_by='count(*) desc', max_records=none, default=none) -%}

{#-- Prevent querying of db in parsing mode. This works because this macro does not create any new refs. #}
{#-- Prevent querying of db in parsing mode. This works because this macro does not create any new refs. #}
{%- if not execute -%}
{{ return('') }}
{% endif %}
{#-- #}

{%- set target_relation = adapter.get_relation(database=table.database,
schema=table.schema,
Expand All @@ -40,12 +27,13 @@ Returns:

{%- else -%}


select
{{ column }} as value

from {{ target_relation }}
group by 1
order by count(*) desc
order by {{ order_by }}

{% if max_records is not none %}
limit {{ max_records }}
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