SELECT type, key
FROM (
SELECT * FROM
js(
(SELECT json, type FROM arboreal-vision-339901.take_home.virtual_kitchen_ubereats_hours
),
-- Input columns.
json, type,
-- Output schema.
"[{name: 'key', type:'string'}, -- error here
{name: 'type', type:'string'}]",
-- The function.
"function(r, emit) {
x=JSON.parse(r.json)
Object.keys(x).forEach(function(entry) {
emit({key:entry, type:r.type,});
});
}"
)
)
LIMIT 10
can't understand why there's an error with "[{name: 'key', type:'string'}
could anyone please help me solve this. thanks!
For multi lines you need to use multi quotation marks i.e ””” or ’’’ at the beginning and end of the string. For more information you can refer to the google cloud documentation .
You can try this below query:
SELECT type, key
FROM (
SELECT * FROM
js(
(SELECT json, type FROM arboreal-vision-339901.take_home.virtual_kitchen_ubereats_hours
),
-- Input columns.
json, type,
-- Output schema.
"""[{name: 'key', type:'string'}, -- error here
{name: 'type', type:'string'}]""",
-- The function.
"""function(r, emit) {
x=JSON.parse(r.json)
Object.keys(x).forEach(function(entry) {
emit({key:entry, type:r.type,});
});
}"""
)
)
LIMIT 10
Related
In MySQL, I am trying to create a JSON_OBJECT from rows of data containing key-value pairs.
Here is the sample data:
CREATE TABLE TempValuePair( MyKey VARCHAR(64), MyValue VARCHAR(64) );
INSERT INTO TempValuePair VALUE
('Country', 'Argentina'),
('Capital', 'Buenos Aires'),
('Population', 45810000 );
The following statement seems to return an argument that conforms to the JSON_OBJECT requirements:
SELECT GROUP_CONCAT(
CONCAT( '\'', MyKey, '\',\'', Myvalue, '\'' )
ORDER BY MyKey
)
FROM TempValuePair;
However, the following statement fails:
SELECT GROUP_CONCAT(
CONCAT( '\'', MyKey, '\',\'', Myvalue, '\'' )
ORDER BY MyKey
)
FROM TempValuePair
);
Any advice about what I am doing wrong would be greatly appreciated. Thanks!
You seem to want json_objectagg, which is available in MySQL since version 5.7. The function aggregates key/value pairs from multiple rows into a single JSON object:
select json_objectagg(mykey, myvalue) as js from TempValuePair;
Yields:
{"Capital": "Buenos Aires", "Country": "Argentina", "Population": "45810000"}
Demo on DB Fiddle
How can I convert below query to json?
SELECT id ,name ,AddTime(created_at ,'04:30:00') as created_at2
I mean that I need something like this:
"select":[ "id","name" ],
"from":[
"table_name"
],
but I don't know how to use AddTime(created_at ,'04:30:00') as created_at2
Seems that you are looking for JSON_OBJECT() function in order to construct a JSON value such as
SELECT JSON_OBJECT(
'id', id,
'name', name,
'created_at2', AddTime(created_at ,'04:30:00')
) AS js
FROM t
Demo
Edit : perhaps you need to add JSON_ARRAY() function such as
SELECT JSON_OBJECT( 'select',
JSON_ARRAY( id, name, AddTime(created_at ,'04:30:00') )
) AS js
FROM t
Demo
I am trying to Insert/update a string (JSON). While inserting/Updating the value I get data truncation error.
I have tried making a JSON type column and passing an JSON_OBJECT() type but that fails as well.
select '''[{"id":"1202","title":"Asian","notes":"","active":"1"}]''';
CREATE TABLE mktesttable (
id int NOT NULL,
s VARCHAR(34530) NOT NULL
);
INSERT INTO mktesttable
select 1, '''[{"id":"1202","title":"Asian","notes":"","active":"1"}]''';
select * from mktesttable;
// That Works
INSERT INTO mktesttable
SELECT
patient_data.id,
CONCAT(
'''[{"id":"', patient_data.race,
'","title":"', list_options.title,
'","notes":"', list_options.notes,
'","active":"', list_options.active,
'"}]'''
) as s
FROM
patient_data
INNER JOIN list_options
ON patient_data.race = list_options.id order by 1 desc
Yields same result (Id's and data varies) but doesn't work
Result Set
If you want to store JSON object, you should use the JSON datatype instead of strings. To create a JSON object, you can use JSON_OBJECT.
CREATE TABLE mktesttable (
id int NOT NULL,
s JSON NOT NULL
);
INSERT INTO mktesttable
SELECT
patient_data.id,
JSON_OBJECT(
'id', patient_data.race,
'title', list_options.title,
'notes', list_options.notes,
'active', list_options.active,
)
FROM
patient_data
INNER JOIN list_options
ON patient_data.race = list_options.id
ORDER BY patient_data.id desc
If you need a JSON array as shown in your sample data, then :
JSON_ARRAY(
JSON_OBJECT(
'id', patient_data.race,
'title', list_options.title,
'notes', list_options.notes,
'active', list_options.active,
)
)
I'd like to convert result table to JSON array in MySQL using preferably only plain MySQL commands. For example with query
SELECT name, phone FROM person;
| name | phone |
| Jack | 12345 |
| John | 23455 |
the expected JSON output would be
[
{
"name": "Jack",
"phone": 12345
},
{
"name": "John",
"phone": 23455
}
]
Is there way to do that in plain MySQL?
EDIT:
There are some answers how to do this with e.g. MySQL and PHP, but I couldn't find pure MySQL solution.
New solution:
Built using Your great comments, thanks!
SELECT JSON_ARRAYAGG(JSON_OBJECT('name', name, 'phone', phone)) from Person;
Old solution:
With help from #Schwern I managed to put up this query, which seems to work!
SELECT CONCAT(
'[',
GROUP_CONCAT(JSON_OBJECT('name', name, 'phone', phone)),
']'
)
FROM person;
You can use json_object to get rows as JSON objects.
SELECT json_object('name', name, 'phone', phone)
FROM person;
This won't put them in an array, or put commas between them. You'll have to do that in the code which is fetching them.
If you're stuck on MySQL 5.6 like me, try this:
SELECT
CONCAT(
'[',
GROUP_CONCAT(
CONCAT(
'{"name":"', name, '"',
',"phone":"', phone, '"}'
)
),
']'
) as json
FROM person
There are two "group by" functions for JSON called json_arrayagg, json_objectagg.
This problem can be solved with:
SELECT json_arrayagg(
json_merge(
json_object('name', name),
json_object('phone', phone)
)
) FROM person;
This requires MySQL 5.7+.
If you need a nested JSON Array Object, you can join JSON_OBJECT with json_arrayagg as below:
{
"nome": "Moon",
"resumo": "This is a resume.",
"dt_inicial": "2018-09-01",
"v.dt_final": null,
"data": [
{
"unidade": "unit_1",
"id_unidade": 9310
},
{
"unidade": "unit_2",
"id_unidade": 11290
},
{
"unidade": "unit_3",
"id_unidade": 13544
},
{
"unidade": "unit_4",
"id_unidade": 13608
}
]
}
You can also do it like this:
CREATE DEFINER=`root`#`localhost` PROCEDURE `get_lst_caso`(
IN `codigo` int,
IN `cod_base` int)
BEGIN
DECLARE json TEXT DEFAULT '';
SELECT JSON_OBJECT(
'nome', v.nome,
'dt_inicial', v.dt_inicial,
'v.dt_final', v.dt_final,
'resumo', v.resumo,
'data', ( select json_arrayagg(json_object(
'id_unidade',`tb_unidades`.`id_unidade`,
'unidade',`tb_unidades`.`unidade`))
from tb_caso_unidade
INNER JOIN tb_unidades ON tb_caso_unidade.cod_unidade = tb_unidades.id_unidade
WHERE tb_caso_unidade.cod_caso = codigo)
) INTO json
FROM v_caso AS v
WHERE v.codigo = codigo and v.cod_base = cod_base;
SELECT json;
END
For most situations, I use DataGreap, but for big tables, it is not work.
My GIST shell script
Using only the native JSON fuctions (no PHP, etc) in MySQL version 5.7.12 (section 13.16 in the manual) I am trying to write a query to generate a JSON document from relational tables that contains a sub object. Given the following example:
CREATE TABLE `parent_table` (
`id` int(11) NOT NULL,
`desc` varchar(20) NOT NULL,
PRIMARY KEY (`id`)
);
CREATE TABLE `child_table` (
`id` int(11) NOT NULL,
`parent_id` int(11) NOT NULL,
`desc` varchar(20) NOT NULL,
PRIMARY KEY (`id`,`parent_id`)
);
insert `parent_table` values (1,'parent row 1');
insert `child_table` values (1,1,'child row 1');
insert `child_table` values (2,1,'child row 2');
I am trying to generate a JSON document that looks like this:
[{
"id" : 1,
"desc" : "parent row 1",
"child_objects" : [{
"id" : 1,
"parent_id" : 1,
"desc" : "child row 1"
}, {
"id" : 2,
"parent_id" : 1,
"desc" : "child row 2"
}
]
}]
I am new to MySQL and suspect there is a SQL pattern for generating nested JSON objects from one to many relationships but I'm having trouble finding it.
In Microsoft SQL (which I'm more familiar with) the following works:
select
[p].[id]
,[p].[desc]
,(select * from [dbo].[child_table] where [parent_id] = [p].[id] for json auto) AS [child_objects]
from [dbo].[parent_table] [p]
for json path
I attempted to write the equivalent in MySQL as follows:
select json_object(
'id',p.id
,'desc',p.`desc`
,'child_objects',(select json_object('id',id,'parent_id',parent_id,'desc',`desc`)
from child_table where parent_id = p.id)
)
from parent_table p;
select json_object(
'id',p.id
,'desc',p.`desc`
,'child_objects',json_array((select json_object('id',id,'parent_id',parent_id,'desc',`desc`)
from child_table where parent_id = p.id))
)
from parent_table p
Both attempts fail with the following error:
Error Code: 1242. Subquery returns more than 1 row
The reason you are getting these errors is that the parent json object is not expecting a result set as one of its inputs, you need to have simple object pairs like {name, string} etc bug report - may be available in future functionality... this just means that you need to convert your multi row results into a concatination of results separated by commas and then converted into a json array.
You almost had it with your second example.
You can achieve what you are after with the GROUP_CONCAT function
select json_object(
'id',p.id
,'desc',p.`desc`
,'child_objects',json_array(
(select GROUP_CONCAT(
json_object('id',id,'parent_id',parent_id,'desc',`desc`)
)
from child_table
where parent_id = p.id))
)
from parent_table p;
This almost works, it ends up treating the subquery as a string which leaves the escape characters in there.
'{\"id\": 1,
\"desc\": \"parent row 1\",
\"child_objects\":
[\"
{\\\"id\\\": 1,
\\\"desc\\\": \\\"child row 1\\\",
\\\"parent_id\\\": 1
},
{\\\"id\\\": 2,
\\\"desc\\\": \\\"child row 2\\\",
\\\"parent_id\\\": 1}\"
]
}'
In order to get this working in an appropriate format, you need to change the way you create the JSON output as follows:
select json_object(
'id',p.id
,'desc',p.`desc`
,'child_objects',(select CAST(CONCAT('[',
GROUP_CONCAT(
JSON_OBJECT(
'id',id,'parent_id',parent_id,'desc',`desc`)),
']')
AS JSON) from child_table where parent_id = p.id)
) from parent_table p;
This will give you the exact result you require:
'{\"id\": 1,
\"desc\": \"parent row 1\",
\"child_objects\":
[{\"id\": 1,
\"desc\": \"child row 1\",
\"parent_id\": 1
},
{\"id\": 2,
\"desc\": \"child row 2\",
\"parent_id\": 1
}]
}'
For MariaDb, CAST AS JSON does not work. But JSON_EXTRACT may be used to convert a string to a JSON object:
select json_object(
'id',p.id
,'desc',p.`desc`
,'child_objects',JSON_EXTRACT(IFNULL((select
CONCAT('[',GROUP_CONCAT(
json_object('id',id,'parent_id',parent_id,'desc',`desc`)
),']')
from child_table where parent_id = p.id),'[]'),'$')
) from parent_table p;
I tried group_concat solution but I found it's problems larger string because of group_concat limitations (group_concat_max_len).
I wrote the new function resolve the problem about converting a string to JSON object as bellow and how to use it.
Tested on MariaDB 10.5.12
Usage: https://i.stack.imgur.com/cWfd7.jpg
CREATE FUNCTION `ut_tf_array`(input_json longtext) RETURNS longtext CHARSET utf8mb4 COLLATE utf8mb4_unicode_ci
COMMENT 'Function for transform json array agg'
BEGIN
DECLARE transformed_data_list longtext ;
DECLARE record longtext ;
DECLARE i_count int ;
DECLARE i_count_items int ;
SET i_count = 0;
SET i_count_items = JSON_LENGTH(JSON_EXTRACT(input_json,'$'));
SET transformed_data_list = '[]';
-- return array with length = zero
IF input_json is NULL THEN
RETURN transformed_data_list;
END IF;
WHILE i_count < i_count_items DO
-- fetch into record
SELECT JSON_EXTRACT( JSON_EXTRACT( input_json ,'$') , CONCAT('$[',i_count,']')) INTO record;
-- append to transformed_data_list
SELECT JSON_ARRAY_APPEND(transformed_data_list, '$', JSON_EXTRACT(record, '$')) into transformed_data_list;
SET i_count := i_count + 1;
END WHILE;
-- done
RETURN transformed_data_list;
END
Below Query works for me.
SELECT JSON_ARRAYAGG(JSON_OBJECT('Id', p.id, 'desc', p.`desc`, 'child_objects', temp_json)) AS json_value
FROM (
SELECT p.id, p.`desc`,
JSON_ARRAYAGG(JSON_OBJECT('id', p.id, 'parent_id', p.parent_id, 'desc', p.`desc`)) AS temp_json
FROM parent_table p
GROUP BY p.id
) t;