How to remove a field in a JSON document in MySQL
- 2 minutes read - 373 wordsYou can remove a field from JSON document in MySQL with the JSON_REMOVE
function.
NOTE: more info is available in the MySQL JSON functions documentation page
👉 Want a FREE MySQL database?👈
🦀 Check Aiven’s FREE plans! 🦀
⚡️ Want to optimize your SQL query with AI? ⚡️
Check Aiven SQL Query Optimizer!
⚡️ Want a Fully MySQL optimized Database? ⚡️
🐧 Check Aiven AI database optimizer! Powered by EverSQL 🐧
The dataset
The dataset is the following:
{
"id": 778,
"shop": "Luigis Pizza",
"name": "Edward Olson",
"phoneNumbers":
["(935)503-3765x4154","(935)12345"],
"address": "Unit 9398 Box 2056 DPO AP 24022",
"image": null,
"pizzas": [
{
"pizzaName": "Salami",
"additionalToppings": ["🥓", "🌶️"]
},
{
"pizzaName": "Margherita",
"additionalToppings": ["🍌", "🌶️", "🍍"]
}
]
}
Check out the description of the fields
The following examples use a pizza order dataset with an order having:id
: 778shop
: “Luigis Pizza”name
: “Edward Olson”phoneNumbers
:["(935)503-3765x4154","(935)12345"]address
: “Unit 9398 Box 2056 DPO AP 24022”image
: null- and two pizzas contained in the
pizzas
item:
[
{
"pizzaName": "Salami",
"additionalToppings": ["🥓", "🌶️"]
},
{
"pizzaName": "Margherita",
"additionalToppings": ["🍌", "🌶️", "🍍"]
}
]
If you want to reproduce the examples, check how to recreate the dataset
It can be recreated with the following script:
create table test(id serial primary key, json_data json);
insert into test(json_data) values (
'{
"id": 778,
"shop": "Luigis Pizza",
"name": "Edward Olson",
"phoneNumbers":
["(935)503-3765x4154","(935)12345"],
"address": "Unit 9398 Box 2056 DPO AP 24022",
"image": null,
"pizzas": [
{
"pizzaName": "Salami",
"additionalToppings": ["🥓", "🌶️"]
},
{
"pizzaName": "Margherita",
"additionalToppings": ["🍌", "🌶️", "🍍"]
}
]
}');
Remove a field from a JSON document with JSON_REMOVE
function
To remove one or more fields from a JSON document you can use the JSON_REMOVE
function. To remove the the pizzaName
from the second pizza in the above order you can:
select
JSON_REMOVE(json_data,'$.pizzas[1].pizzaName') remove_pizzaName from test;
Where
json_data
is the JSON column$.pizzas[1].pizzaName
selects thepizzas
item, the 2nd element in the array and thepizzaName
subitem
Result
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| remove_pizzaName |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| {"id": 778, "name": "Edward Olson", "shop": "Luigis Pizza", "image": null, "pizzas": [{"pizzaName": "Salami", "additionalToppings": ["🥓", "🌶️"]}, {"additionalToppings": ["🍌", "🌶️", "🍍"]}], "address": "Unit 9398 Box 2056 DPO AP 24022", "phoneNumbers": ["(935)503-3765x4154", "(935)12345"]} |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
Review all the JSON MySQL use-cases listed in the main page