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json in sql
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‎examples/official-site/sqlpage/migrations/50_blog_json.sql‎

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INSERT INTO blog_posts (title, description, icon, created_at, content)
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VALUES
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(
@@ -62,9 +61,9 @@ FROM users;
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| user_json |
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|-----------|
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| {"name":"Alice","birthday":"1990-01-15"} |
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| {"name":"Bob","birthday":"1985-05-22"} |
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| {"name":"Charlie","birthday":"1992-09-30"} |
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| `{"name":"Alice","birthday":"1990-01-15"}` |
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| `{"name":"Bob","birthday":"1985-05-22"}` |
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| `{"name":"Charlie","birthday":"1992-09-30"}` |
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### Creating a JSON array
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| user_array |
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|------------|
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| ["Alice","1990-01-15","Admin"] |
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| ["Bob","1985-05-22","User"] |
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| ["Charlie","1992-09-30","User"] |
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| `["Alice","1990-01-15","Admin"]` |
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| `["Bob","1985-05-22","User"]` |
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| `["Charlie","1992-09-30","User"]` |
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### Aggregating multiple values into a JSON array
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| names |
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|-------|
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| ["Alice","Bob","Charlie"] |
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| `["Alice","Bob","Charlie"]` |
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### Aggregating values into a JSON object
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```sql
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SELECT json_group_object(name, birthday) AS name_birthday_map
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SELECT json_group_object(name, group_name) AS name_group_map
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FROM users;
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```
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| name_birthday_map |
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| name_group_map |
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|-------------------|
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| {"Alice":"1990-01-15","Bob":"1985-05-22","Charlie":"1992-09-30"} |
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| `{"Alice":"Admin", "Bob":"User", "Charlie":"User"}` |
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### Iterating over a JSON array
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For more complex JSON structures, you can use the `json_tree()` function, which recursively walks through the entire JSON structure.
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These iteration functions can be used to test whether a value is present in a JSON array. For instance, to create a
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[multi-value select dropdown](documentation.sql?component=form#component) with pre-selected values, you can use the following query:
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These iteration functions can be used to check if specific values exist in a JSON array.
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Here''s a practical example:
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Let''s say you have a form with a [multiple-choice dropdown](documentation.sql?component=form#component) that allows selecting multiple users.
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Some users might already be selected, and their IDs are stored in a JSON array passed as an URL parameter called `$selected_ids`.
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You can create this dropdown using the following query:
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```sql
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select json_group_array(json_object(
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''label'', name
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''label'', name,
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''value'', id,
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''selected'', id in (select value from json_each_text($selected_ids))
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)) as options
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from users;
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```
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This query will:
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1. Create a dropdown option for each user
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2. Use their name as the display label
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3. Use their ID as the value
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4. Mark the option as selected if the user's ID exists in the $selected_ids array
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### Combining two JSON objects
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SQLite provides the `json_patch()` function to combine two JSON objects. This function takes two JSON objects as arguments and returns a new JSON object that is the result of merging the two input objects.
@@ -156,26 +164,35 @@ See [the list of JSON functions in PostgreSQL](https://www.postgresql.org/docs/c
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### Creating a JSON object
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```sql
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SELECT jsonb_build_object(''name'', name, ''birthday'', birthday) AS user_json FROM users;
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SELECT
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jsonb_build_object(
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''name'', name,
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''birthday'', birthday
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) AS user_json
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FROM users;
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```
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| user_json |
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|-----------|
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| {"name": "Alice", "birthday": "1990-01-15"} |
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| {"name": "Bob", "birthday": "1985-05-22"} |
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| {"name": "Charlie", "birthday": "1992-09-30"} |
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| `{"name":"Alice","birthday":"1990-01-15"}` |
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| `{"name":"Bob","birthday":"1985-05-22"}` |
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| `{"name":"Charlie","birthday":"1992-09-30"}` |
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### Creating a JSON array
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```sql
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SELECT jsonb_build_array(name, birthday, group_name) AS user_array FROM users;
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SELECT
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jsonb_build_array(
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name, birthday, group_name
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) AS user_array
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FROM users;
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```
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| user_array |
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|------------|
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| ["Alice", "1990-01-15", "Admin"] |
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| ["Bob", "1985-05-22", "User"] |
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| ["Charlie", "1992-09-30", "User"] |
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| `["Alice", "1990-01-15", "Admin"]` |
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| `["Bob", "1985-05-22", "User"]` |
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| `["Charlie", "1992-09-30", "User"]` |
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### Aggregating multiple values into a JSON array
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| names |
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|-------|
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| ["Alice", "Bob", "Charlie"] |
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| `["Alice","Bob","Charlie"]` |
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### Aggregating values into a JSON object
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```sql
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SELECT jsonb_object_agg(name, birthday) AS name_birthday_map
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SELECT
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jsonb_object_agg(
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name, birthday
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) AS name_birthday_map
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FROM users;
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```
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| name_birthday_map |
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|-------------------|
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| `{"Alice": "1990-01-15", "Bob": "1985-05-22", "Charlie": "1992-09-30"}` |
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| `{"Alice":"1990-01-15","Bob":"1985-05-22","Charlie":"1992-09-30"}` |
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### Iterating over a JSON array
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| user_json |
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|-----------|
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| {"name": "Alice", "birthday": "1990-01-15"} |
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| {"name": "Bob", "birthday": "1985-05-22"} |
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| {"name": "Charlie", "birthday": "1992-09-30"} |
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| `{"name":"Alice","birthday":"1990-01-15"}` |
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| `{"name":"Bob","birthday":"1985-05-22"}` |
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| `{"name":"Charlie","birthday":"1992-09-30"}` |
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### Creating a JSON array
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| user_array |
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|------------|
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| ["Alice", "1990-01-15", "Admin"] |
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| ["Bob", "1985-05-22", "User"] |
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| ["Charlie", "1992-09-30", "User"] |
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| `["Alice","1990-01-15","Admin"]` |
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| `["Bob","1985-05-22","User"]` |
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| `["Charlie","1992-09-30","User"]` |
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### Aggregating multiple values into a JSON array
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| names |
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|-------|
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| ["Alice", "Bob", "Charlie"] |
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| `["Alice","Bob","Charlie"]` |
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### Aggregating values into a JSON object
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| name_birthday_map |
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|-------------------|
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| {"Alice": "1990-01-15", "Bob": "1985-05-22", "Charlie": "1992-09-30"} |
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| `{"Alice":"1990-01-15","Bob":"1985-05-22","Charlie":"1992-09-30"}` |
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### Iterating over a JSON array
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| user_json |
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|-----------|
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| {"name":"Alice","birthday":"1990-01-15"} |
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| {"name":"Bob","birthday":"1985-05-22"} |
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| {"name":"Charlie","birthday":"1992-09-30"} |
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| `{"name":"Alice","birthday":"1990-01-15"}` |
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| `{"name":"Bob","birthday":"1985-05-22"}` |
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| `{"name":"Charlie","birthday":"1992-09-30"}` |
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Alternatively, you can use the `JSON_OBJECT` function:
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| user_array |
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|------------|
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| [{"name":"Alice","birthday":"1990-01-15","group_name":"Admin"}] |
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| [{"name":"Bob","birthday":"1985-05-22","group_name":"User"}] |
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| [{"name":"Charlie","birthday":"1992-09-30","group_name":"User"}] |
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| `[{"name":"Alice","birthday":"1990-01-15","group_name":"Admin"}]` |
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| `[{"name":"Bob","birthday":"1985-05-22","group_name":"User"}]` |
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| `[{"name":"Charlie","birthday":"1992-09-30","group_name":"User"}]` |
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You can also use the `JSON_ARRAY` function:
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| names |
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|-------|
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| [{"name":"Alice"},{"name":"Bob"},{"name":"Charlie"}] |
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| `[{"name":"Alice"},{"name":"Bob"},{"name":"Charlie"}]` |
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Alternatively, use the `JSON_ARRAYAGG` function:
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