Parse JSON in MySQL - mysql

I need help on how to parse JSON data in MySQL.
I can parse a column named config containing data such as:
{"encounterId":"f45bf821-98e1-4496-82ef-047971e168cb","providerId":"38001853-d2e1-4361-9fff-cfca1aedf406","patientId":"f4d04edb-652f-427c-ac25-6fecbda2a0aa","obs":[{"conceptId":"4e903795-ad79-48fc-851e-9e67c9628e6b","value":0.0},{"conceptId":"5300c3e4-3b53-4a0b-874b-3060d18cec9b","value":"Q"},{"conceptId":"dded4485-6160-4791-a13d-16c87f5004dc","value":"000019"},{"conceptId":"4e503f63-caa0-419a-8670-112441d228da","value":"girl"}],"dateCreated":"Dec 5, 2012 9:39:01 AM","formId":"ETAT","locationId":"","created":1354693141902}
by using
select common_schema.get_option(be.config,'encounterid') AS eid
, common_schema.get_option(be.config,'providerid') AS gender
, common_schema.get_option(be.config,'patientid') AS pid
from bencounter be
to get what I need.
However, I am unable to get the data for 'obs' which is several 'rows' of the fields conceptid and value.
Further more any reference to a field after the 'set' of obs returns a null
select common_schema.get_option(be.config,'encounterid') AS eid
, common_schema.get_option(be.config,'providerid') AS gender
, common_schema.get_option(be.config,'patientid') AS pid
, common_schema.get_option(be.config,'formId') AS formid -- THIS RETURNS NULL
from bencounter be
Can some one please help me figure this out.
I would like to solve this directly in MySQL...
Clemens

Here's a solution in MySQL 5.7 syntax:
select be.config->'$.encounterId' AS eid
, be.config->'$.providerId' AS gender
, be.config->'$.patientId' AS pid
, be.config->'$.formId' AS formid
from bencounter be \G
Output:
*************************** 1. row ***************************
eid: "f45bf821-98e1-4496-82ef-047971e168cb"
gender: "38001853-d2e1-4361-9fff-cfca1aedf406"
pid: "f4d04edb-652f-427c-ac25-6fecbda2a0aa"
formid: "ETAT"
Remember that field keys in JSON are case-sensitive. For example, 'formId' is not the same as 'formid'.

It appears you are using https://common-schema.googlecode.com/svn/trunk/common_schema/doc/html/get_option.html. It specifies that subdictionaries are not supported, which I think is your problem here.
Mysql is not a great tool for parsing JSON.
I think there are some efforts for future versions like 5.7 to start including some support for JSON (see http://blog.ulf-wendel.de/2014/mysql-5-7-http-plugin-mysql/).
If you are on an earlier version now you might try using UDFs like http://www.slideshare.net/mobile/SvetaSmirnova/mysql-json-functions
HTH

Either you could use a cumbersome MySQL UDF for parsing JSON for MySQL like for example https://github.com/ChrisCinelli/mysql_json
...but a better way would be to pull out the JSON and parse it in your app, and perhaps convert the data to a more suited schema for your intentions.

Related

how to include hard-coded value to output from mysql query?

I've created a MySQL sproc which returns 3 separate result sets. I'm implementing the npm mysql package downstream to exec the sproc and get a result structured in json with the 3 result sets. I need the ability to filter the json result sets that are returned based on some type of indicator in each result set. For example, if I wanted to get the result set from the json response which deals specifically with Suppliers then I could use some type of js filter similar to this:
var supplierResultSet = mySqlJsonResults.filter(x => x.ResultType === 'SupplierResults');
I think SQL Server provides the ability to include a hard-coded column value in a SQL result set like this:
select
'SupplierResults',
*
from
supplier
However, this approach appears to be invalid in MySQL b/c MySQL Workbench is telling me that the sproc syntax is invalid and won't let me save the changes. Do you know if something like what I'm trying to achieve is possible in MySQL and if not then can you recommend alternative approaches that would help me achieve my ultimate goal of including some type of fixed indicator in each result set to provide a handle for downstream filtering of the json response?
If I followed you correctly, you just need to prefix * with the table name or alias:
select 'SupplierResults' hardcoded, s.* from supplier s
As far as I know, this is the SQL Standard. select * is valid only when no other expression is added in the selec clause; SQL Server is lax about this, but most other databases follow the standard.
It is also a good idea to assign a name to the column that contains the hardcoded value (I named it hardcoded in the above query).
In MySQL you can simply put the * first:
SELECT *, 'SupplierResults'
FROM supplier
Demo on dbfiddle
To be more specific, in your case, in your query you would need to do this
select
'SupplierResults',
supplier.* -- <-- this
from
supplier
Try this
create table a (f1 int);
insert into a values (1);
select 'xxx', f1, a.* from a;
Basically, if there are other fields in select, prefix '*' with table name or alias

Json_object in Oracle returns ORA-00907: missing right parenthesis

I am trying to convert Oracle table data into JSON files. I have three databases and the below code gives output as JSON file in one DB but the other two databases throw ORA-00907: missing right parenthesis error.
Syntactically it is correct, as it gave output in one DB. Don't understand what is going wrong.
This is in Oracle DB, How do I find out which version of Oracle is installed in those DB's and if they are 12.2 and above, Is there a way to fix this issue? All I want is to convert the output of a select statement to a json file. Thanks in advance
code:
SELECT JSON_OBJECT ( 'empid' value eid , 'name' value ename , 'add' value eaddr )
FROM abc.emp
JSON_Object is available from Oracle version 12.2 .
Run the query Select * from v$version to check your oracle version

SQL Querying inside XML column

Am trying to Query inside an SQL table which has XML Column .
Table name: 'Purchase'
Column name: 'XML_COL'
Please find below xml data for column name 'XML_COL' under purchase table:
<ns1:Request xmlns:ns1="http://www.sample.com/hic/event/request"
xmlns:ns2="http://www.sample.com/hic/eventpayload/request">
<ns1:createeventRequest>
<ns1:eventPayLoad>
<ns2:eventPayLoad>
<Id>123456</Id>
</ns2:eventPayLoad>
</ns1:eventPayLoad>
</ns1:createeventRequest>
</ns1:Request>
I have written below query :
`select * from purchase,
XMLTABLE ('$d/Request/createeventRequest/eventPayLoad/eventPayLoad' PASSING XML_COL as "d"
COLUMNS
Id varchar(20) PATH 'Id') as a where(a.Id like '1234%');`
But this is returning me an empty column with no data.
But my requirement is it should fetch all the data for this particular Id.
Please help if any one faced this kind of issue.
Do we need to include namespaces as well while querying?? or am I missing any thing?
I think the expression PATH 'Id' is bit to simple...
I'm not familiar with MySQL's abilities to query XML... The Path Id would try to find an element "Id" from the current node (which is the root node in the first action). But there is no "Id"... You must either specify the full path, starting with a single / to start at the root node, or let the engine try a deep search, starting with two //
These paths should work:
SELECT ExtractValue(
'<ns1:Request xmlns:ns1="http://www.sample.com/hic/event/request" xmlns:ns2="http://www.sample.com/hic/eventpayload/request">
<ns1:createeventRequest>
<ns1:eventPayLoad>
<ns2:eventPayLoad>
<Id>123456</Id>
</ns2:eventPayLoad>
</ns1:eventPayLoad>
</ns1:createeventRequest>
</ns1:Request>',
'/ns1:Request[1]/ns1:createeventRequest[1]/ns1:eventPayLoad[1]/ns2:eventPayLoad[1]/Id[1]' ) AS result;
If there is only one element with a value (in your case "Id") you might use the simple deep search like this:
SELECT ExtractValue(
'<ns1:Request xmlns:ns1="http://www.sample.com/hic/event/request" xmlns:ns2="http://www.sample.com/hic/eventpayload/request">
<ns1:createeventRequest>
<ns1:eventPayLoad>
<ns2:eventPayLoad>
<Id>123456</Id>
</ns2:eventPayLoad>
</ns1:eventPayLoad>
</ns1:createeventRequest>
</ns1:Request>',
'//Id[1]' ) AS result;
But - in general - it is good advise to be as specific as possible...
Just cracked the query...When name spaces are being used in an XML, instead of the entire path, I found it's better to use '/*//' which traverses through the required element tag through XML.
Final Query:
select * from purchase,
XMLTABLE('$d' PASSING XML_COL as "d"
COLUMNS
Id varchar(20) PATH '/*//Id') as a where(a.Id like '1234%') with ur
Using 'with ur' helps to read the data that has not been committed in the database.
Please post comments if it is helpful.

Select query returns false result

eg:
Table : user
column : user_id (type is int)
SELECT * FROM user WHERE user_id = '10xyz'
is giving same result of
SELECT * FROM user WHERE user_id = '10'
The input value is not integer but not giving an error in this case.
The reason why you are getting the same result is because MySQL automatically removes the trailing characters from the string and implicitly converts it to integer.
SQLFiddle Demo
SQLFiddle Demo (updated)
If you don't want to change all your code, but you have your database queries all going through one or a few subs, you can change those to check for warnings after using a statement handle (e.g. if ( $sth->{mysql_warning_count} ) ...).
Or you can create a DBI subclass that does that automatically for you, promoting warnings to errors. If you do, many others have use for such a thing. There are configuration settings to give an error instead of a warning when updating or inserting something like '10xyz' into an integer field, but not anything broader than that, and dear Oracle considers it Not a Bug. Maybe MariaDB does (or could do) better?
datatype of user_id is in database is INT
that why it giving same output and not error

Entity Framework - MySQL - Datetime format issue

I have a simple table with few date fields.
Whenever I run following query:
var docs = ( from d in base.EntityDataContext.document_reviews
select d ).ToList();
I get following exception:
Unable to convert MySQL date/time value to System.DateTime.
MySql.Data.Types.MySqlConversionException: Unable to convert MySQL date/time value to System.DateTime
The document reviews table has two date/time fields. One of them is nullable.
I have tried placing following in connection string:
Allow Zero Datetime=true;
But I am still getting exception.
Anyone with a solution?
#effkay - if you solved this it would be great if you could post the answer.
Also if anyone else has a solution that would be great too :).
Edit:
The solution can be found in the http://dev.mysql.com/doc/refman/5.1/en/connector-net-connection-options.html connector documentation.
I needed to set "Convert Zero Datetime" to true, and now it works.
hth.
You need to set Convert Zero Datetime=True in connection string of running application