get_value¶

Call or Deploy get_value ?

✅ You can call this get_value bigfunction directly from your Google Cloud Project (no install required).

This get_value function is deployed in bigfunctions GCP project in 39 datasets for all of the 39 BigQuery regions. You need to use the dataset in the same region as your datasets (otherwise you may have a function not found error).
Function is public, so it can be called by anyone. Just copy / paste examples below in your BigQuery console. It just works!
You may prefer to deploy the BigFunction in your own project if you want to build and manage your own catalog of functions. This is particularly useful if you want to create private functions (for example calling your internal APIs). Discover the framework

Public BigFunctions Datasets:

Region	Dataset
`eu`	`bigfunctions.eu`
`us`	`bigfunctions.us`
`europe-west1`	`bigfunctions.europe_west1`
`asia-east1`	`bigfunctions.asia_east1`
...	...

Description¶

Signature

get_value(key_value_items, search_key)

Description

Return the first value with a key search_key from key_value_items (or return null if search_key does not exist in key_value_items).

Examples¶

EUUSeurope-west1

select bigfunctions.eu.get_value([struct('a' as key, 8 as value), struct('b' as key, 9 as value)], 'a')

select bigfunctions.us.get_value([struct('a' as key, 8 as value), struct('b' as key, 9 as value)], 'a')

select bigfunctions.europe_west1.get_value([struct('a' as key, 8 as value), struct('b' as key, 9 as value)], 'a')

+-------+
| value |
+-------+
| 8     |
+-------+

EUUSeurope-west1

select bigfunctions.eu.get_value([struct('a' as key, 8 as value), struct('b' as key, 9 as value)], 'c')

select bigfunctions.us.get_value([struct('a' as key, 8 as value), struct('b' as key, 9 as value)], 'c')

select bigfunctions.europe_west1.get_value([struct('a' as key, 8 as value), struct('b' as key, 9 as value)], 'c')

+-------+
| value |
+-------+
| null  |
+-------+

3. When there are multiple occurences of search_key, return the first found value

EUUSeurope-west1

select bigfunctions.eu.get_value([struct('a' as key, 8 as value), struct('a' as key, 9 as value)], 'a')

select bigfunctions.us.get_value([struct('a' as key, 8 as value), struct('a' as key, 9 as value)], 'a')

select bigfunctions.europe_west1.get_value([struct('a' as key, 8 as value), struct('a' as key, 9 as value)], 'a')

+-------+
| value |
+-------+
| 8     |
+-------+

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If the function does not work as expected, please

report a bug so that it can be improved.
or open the discussion with the community on Slack.

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Use cases¶

This get_value function is useful for extracting values from arrays of key-value pairs (structs). Here are a few use cases:

1. Parameter Extraction: Imagine you have a table storing event data, where one column contains parameters as an array of key-value structs:

| event_id | parameters                                      |
|----------|-------------------------------------------------|
| 1        | [{'key': 'user_id', 'value': '123'}, {'key': 'event_type', 'value': 'purchase'}] |
| 2        | [{'key': 'item_id', 'value': '456'}, {'key': 'user_id', 'value': '789'}] |

You could use get_value to extract the user_id for each event:

SELECT
    event_id,
    bigfunctions.YOUR_REGION.get_value(parameters, 'user_id') AS user_id
FROM
    your_table;

This would give you:

| event_id | user_id |
|----------|---------|
| 1        | 123     |
| 2        | 789     |

2. Configuration Management: Suppose you store configuration settings as key-value pairs in a table:

| setting_group | settings                                       |
|---------------|-------------------------------------------------|
| website       | [{'key': 'theme', 'value': 'dark'}, {'key': 'font_size', 'value': '16px'}] |
| mobile_app    | [{'key': 'version', 'value': '1.2.3'}, {'key': 'platform', 'value': 'ios'}] |

You could retrieve specific settings using get_value:

SELECT
    setting_group,
    bigfunctions.YOUR_REGION.get_value(settings, 'theme') AS theme
FROM
    your_config_table
WHERE setting_group = 'website';

3. Product Attributes: E-commerce platforms often store product attributes as key-value pairs. get_value can help extract these attributes:

| product_id | attributes                                     |
|------------|-------------------------------------------------|
| 1          | [{'key': 'color', 'value': 'red'}, {'key': 'size', 'value': 'L'}] |
| 2          | [{'key': 'weight', 'value': '1kg'}, {'key': 'material', 'value': 'cotton'}] |

You can extract the color of product 1 with:

SELECT bigfunctions.YOUR_REGION.get_value(attributes, 'color') AS color
FROM your_product_table
WHERE product_id = 1;

These are just a few examples. Anytime you have data stored as an array of key-value pairs in BigQuery, get_value can be a convenient way to access the values associated with specific keys. Remember to replace YOUR_REGION with the appropriate BigQuery region for your data.

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