I'm trying to figure out how to work with a list datatype in a Gridgain query, I have an object which has a field
#QuerySqlField private final List<Integer> expertGroupIds; that I can receive during selects but I can't manage to create an update query on the list, and can't find anywhere what is the correct syntax while working from the Gridgain sqlline client.
Also, what I'm finally trying to achieve is to have a select query that will find all objects where expertGroupIds has at least one element similar to a list receive as a parameter (basically I need to check if the 2 lists have any intersections)
Thanks for your help!
You can't is the short answer. There's no way to filter (a WHERE clause) or update it from SQL.
But you can if you normalise it, as you would with a traditional relational database.
Related
I've got a bigquery import from a firestore database where I want to query on a particular field from a document. This was populated via the firestore-bigquery extension and the document data is stored as a JSON string.
I'm trying to use a WHERE clause in my query that uses one of the fields from the JSON data. However this doesn't seem to work.
My query is as follows:
SELECT json_extract(data,'$.title') as title,p
FROM `table`
left join unnest(json_extract_array(data, '$.tags')) as p
where json_extract(data,'$.title') = 'technology'
data is the JSON object and title is an attribute of all of the items. The above query will run but yield 'no results' (There are definitely results there for the title in question as they appear in the table preview).
I've tried using WHERE title = 'technology' as well but this returns an error that title is an unrecognized field (hence the json_extract).
From my research this should work as a standard SQL JSON query but doesn't seem to work on Bigquery. Does anyone know of a way around this?
All I can think of is if I put the results in another table, but I don't know if that's a workable solution as the data is updated via the extension on an update, so I would need to constantly refresh my second table as well.
Edit
I'm wondering if configuring a view would help with this? Though ultimately I would like to query this based on different parameters and the docs here https://cloud.google.com/bigquery/docs/views suggest you can't reference query parameters in a view
I've since managed to work this out, and will share the solution for anyone else with the same problem.
The solution was to use JSON_VALUE in the WHERE clause instead e.g:
where JSON_VALUE(data,'$.title') = 'technology';
I'm still not sure if this is the best way to do this in terms of performance and cost so I will wait to see if anyone else leaves a better answer.
When you read in a result set in Groovy it comes in a collection of maps.
Seems like you should be able to update values inside those maps and write them back out, but I can't find anything built into groovy to allow me to do so.
I'm considering writing a routine that allows me to write a modified map by iterating over the fields of one of the result objects, taking each key/value pair and using them to create the appropriate update statement, but it could be annoying so I was wondering if anyone else had done this or if it'sa vailable already in groovy.
It seems like just a few lines of code so I'd rather not bring in hibernate for this. I'm just thinking a little "update" method that would allow:
def rows=sql.rows(query)
rows[0].name="newName"
update(sql, rows[0])
to update the first guy's name in the database. Anyone seen/created such a monster, or is something like this already built into Groovy Sql and I'm just missing it?
(I suppose you may have to point out to the update method which field is the key field, but that's doable...)
Using the rows method will actually read out all of the values into a List of GroovyRowResult so it's not really possible to update the data without creating an update method like the one you mention.
It's not really possible to do that in the generic case because your query can contain joins or a column reference that is an aggregate, etc.
If you're selecting from a single table use the Sql.eachRow method however and set the ResultSet to be an updatable one, you can use the underlying ResultSet interface to update as you iterate through:
sql.resultSetConcurrency = ResultSet.CONCUR_UPDATABLE
sql.resultSetType = ResultSet.TYPE_FORWARD_ONLY
sql.eachRow(query) { row ->
row.updateString('name', 'newName')
row.updateRow()
}
Depending on the database/driver you use, you may not be able to create an updatable ResultSet.
How can i implement a KeywordFilter field to filter data from the database table as soon as text is fed into the field.
Most of the samples I have come across demonstrates filtering from predefined arrays.What i am looking out for is filtering from database.
Please guide how to go about it.Thanks
I have tried out this example of BB docs which shows in arrays
A straightforward approach would be to load the data from the database into a ReadableList and pass that to the KeywordFilterField.
The method used to set the values is
setSourceList(ReadableList list, KeywordProvider helper)
ReadableList is an interface which has a few implementations. The example code you are looking at uses the SortedReadableList but a BasicFilteredList would work nicely too.
I have that table:
create table t_place(
f_plc_timefrom time,
f_plc_timeto time,
f_plc_minute_cost Decimal(18,4)[24]
);
So, I can create array field, but I don't know, how can I fill in this array field in SQL code. I tryed to find way in many sources, but I could find nothing. I need your help.
AFAIK one can work with arrays only via API, there is no SQL syntax for that.
There is virtually no array support in Firebird in the query and procedural language. As ain says there is only some support via the API. Removal of the array functionality is on the table as well. See also ticket CORE-710.
I have 150+ SQL queries in separate text files that I need to analyze (just the actual SQL code, not the data results) in order to identify all column names and table names used. Preferably with the number of times each column and table makes an appearance. Writing a brand new SQL parsing program is trickier than is seems, with nested SELECT statements and the like.
There has to be a program, or code out there that does this (or something close to this), but I have not found it.
I actually ended up using a tool called
SQL Pretty Printer. You can purchase a desktop version, but I just used the free online application. Just copy the query into the text box, set the Output to "List DB Object" and click the Format SQL button.
It work great using around 150 different (and complex) SQL queries.
How about using the Execution Plan report in MS SQLServer? You can save this to an xml file which can then be parsed.
You may want to looking to something like this:
JSqlParser
which uses JavaCC to parse and return the query string as an object graph. I've never used it, so I can't vouch for its quality.
If you're application needs to do it, and has access to a database that has the tables etc, you could run something like:
SELECT TOP 0 * FROM MY_TABLE
Using ADO.NET. This would give you a DataTable instance for which you could query the columns and their attributes.
Please go with antlr... Write a grammar n follow the steps..which is given in antlr site..eventually you will get AST(abstract syntax tree). For the given query... we can traverse through this and bring all table ,column which is present in the query..
In DB2 you can append your query with something such as the following, but 1 is the minimum you can specify; it will throw an error if you try to specify 0:
FETCH FIRST 1 ROW ONLY