How to Update A Json Field In Postgresql?

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To update a JSON field in PostgreSQL, you can use the jsonb_set function. This function allows you to modify values within a JSON object by specifying the path to the field you want to update.


For example, if you have a table named users with a column named data that stores JSON data, you can update a specific field within the JSON object like this:

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UPDATE users
SET data = jsonb_set(data, '{key}', '"new_value"', true)
WHERE id = 1;


In this example, jsonb_set is used to update the value of the field with the key key to the new value "new_value" for the record with id = 1.


You can also use jsonb_set to add new fields to the JSON object or delete existing fields by setting the third argument to either true or false.


Overall, updating a JSON field in PostgreSQL requires using the jsonb_set function along with the appropriate path and new value to make the desired modifications.

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How to update a json field with values from a function in postgresql?

You can update a JSON field in PostgreSQL with values from a function using the UPDATE statement along with the SET clause and the jsonb_set function.


Here is an example of how you can update a JSON field named data in a table named your_table with values returned from a function named your_function:

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UPDATE your_table
SET data = jsonb_set(data, '{key}', your_function(data->>'key'))
WHERE /* add your condition to filter the rows to be updated */;


In this example:

  • your_table is the name of the table you want to update.
  • data is the JSON field you want to update.
  • 'key' is the key in the JSON object that you want to update.
  • your_function is the function that returns the new value for the JSON field based on the existing value.


Make sure to replace your_table, data, key, and your_function with the actual table name, JSON field name, key, and function name in your database.


Remember to also add a WHERE clause to filter the rows you want to update based on your criteria.


How to update a json field using a subquery in postgresql?

To update a JSON field using a subquery in PostgreSQL, you can use the UPDATE statement along with the jsonb_set function. Here's an example of how you can do this:


Let's say you have a table called data with a JSON field called json_data and you want to update the value of a specific key within that JSON field using a subquery. For example, you want to update the value of the key "name" to "John" where the key "id" is equal to 1.

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UPDATE data
SET json_data = jsonb_set(json_data, '{name}', '"John"')
WHERE id = 1;


In this example, the jsonb_set function is used to update the value of the key "name" to "John" within the json_data field. The WHERE clause specifies that the update should only be applied to rows where the key "id" is equal to 1.


You can customize the query to fit your particular JSON structure and conditions. Make sure to test your query before running it in a production environment.


How to update a json field with values from a join in postgresql?

To update a JSON field with values from a join in PostgreSQL, you can use the UPDATE statement along with the jsonb_set function to update the JSON field with the values from the joined table. Here is an example:


Suppose you have a table table1 with a JSON field data and you want to update this field with values from another table table2 that is joined on a common column id.

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UPDATE table1
SET data = jsonb_set(data, '{key}', to_jsonb(table2.value))
FROM table2
WHERE table1.id = table2.id;


In this query:

  • jsonb_set function is used to update the JSON field data with the value from table2.value.
  • to_jsonb function is used to convert the value from table2.value to JSON data type.
  • The FROM clause is used to join table2 with table1 based on the common column id.
  • The WHERE clause specifies the join condition.


Make sure to replace table1, data, key, table2, value, and id with your actual table and column names.


This query will update the JSON field in table1 with values from table2 based on the join condition specified.


How to update multiple json fields in a single query in postgresql?

In PostgreSQL, you can update multiple JSON fields in a single query by using the jsonb_set function. Here's an example of how you can update multiple JSON fields in a single query:

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UPDATE your_table
SET your_json_column = jsonb_set(
    jsonb_set(your_json_column, '{field1}', '"new_value1"'),
    '{field2}', '"new_value2"'
)
WHERE your_condition;


In this example:

  • your_table is the name of the table where the JSON data is stored
  • your_json_column is the name of the column that contains the JSON data
  • {field1} and {field2} are the keys of the JSON fields you want to update
  • "new_value1" and "new_value2" are the new values for the JSON fields
  • your_condition is the condition that specifies which rows should be updated


You can update as many JSON fields as you want by chaining multiple jsonb_set functions within the jsonb_set function in the SET clause of the UPDATE statement.


How to update a json field based on a condition in postgresql?

To update a JSON field based on a condition in PostgreSQL, you can use the UPDATE statement with the jsonb_set function.


Here's an example:

  1. Suppose you have a table called data_table with a JSON field called json_data.
  2. To update the json_data field where the id is equal to a specific value and the name is equal to a specific value, you can use the following query:
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UPDATE data_table
SET json_data = jsonb_set(json_data, '{field_to_update}', '"new_value"', true)
WHERE json_data->>'id' = '1' AND json_data->>'name' = 'John';


In this query:

  • UPDATE data_table specifies the table to update.
  • SET json_data = jsonb_set(json_data, '{field_to_update}', '"new_value"', true) updates the JSON field json_data by setting a new value for the specified key field_to_update.
  • WHERE json_data->>'id' = '1' AND json_data->>'name' = 'John' specifies the condition where id is equal to 1 and name is equal to John.


Make sure to adjust the table name, JSON field, key to update, new value, and condition based on your specific requirements.

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