I’m using NestJS with TypeORM, database is MySQL, and I’d like to filter multiple parameters that can be passed in.
The frontend has a list of products and filters are applied as query params sent to NestJS, filtering works for a single param eg api.example.com?manufacturer=Acer but how would I filter an Array eg api.example.com?manufacturer=Acer,Toshiba,Asus.
I tried quite a few things in TypeORM, currently using the QueryBuilder to build the array with an if statement if the filter exists if so I’m doing something like a where statement.
.andWhere(manufacturer = filterOne, {filterOne: *manufacturers from the query param*})
But yeah just can’t hack something together, tried a couple of things, above is a rough example, did try methods that TypeORM had as an example on filtering arrays but it seemed like it was more for an array of integers only? Regardless, I’m open to any methods that allow for the end result of filtering the example I provided, cheers and thanks again!
You have to use IN to get all data where manufacturer equal the data came from the query, first, you have to convert the query to an array:
var manufacturerParam = filterOne.split(",");
then add it to your query:
.andWhere(manufacturer IN (:filter)", { filter: manufacturerParam })
I'm trying to filter my users list by comparing two parameters
query="EmployeeData.EmployeeID=externalId"
EmployeeData.EmployeeID is a custom schema that is populated, with a cron job, with the same value as externalId.
Of course I let the cron do the field copy only if necessary, this is the reason I'm trying to filtering the users list.
In the way i wrote seems that the query trying to looking for a value "externalId" into the EmployeeData.EmployeeID ignoring that "externalId" is a even a field
any suggestion?
The way your code is written, the query sent to Google's servers is as you correctly guessed the following:
EmployeeData.EmployeeID=externalId where your actual externalId is not sent but rather the string "externalId".
To replace this string for the actual value of your variable, you can use what is called "string concatenation" 1. To do it, you just need to modify your code as shown below:
query="EmployeeData.EmployeeID=" + externalId;
This way, the query will be sent as you need to Google's servers.
My goal is very simple and I would guess it is a very common goal among web developers.
I am creating a Rails (5.1) application, and I simply want to use AJAX to get the value of a specific cell in a specific row of a specific table in my database (later I am going to use that value to highlight some text on the current page in the user's browser).
I have not been able to find any documentation online explaining how to do this. As I said, it seems like a basic task to ask of jquery and ajax, so I'm confused as to why I'm having so much trouble figuring it out.
For concreteness, say I have a table called 'animals', and I want to get the value of the column 'species' for the animal with 'id' = 99.
How can I construct an AJAX call to query the database for the value of 'species' for the 'animal' with 'id' = 99 .
Though some DBs provide a REST API, what we commonly do is define a route in the app to pull and return data from the DB.
So:
Add a route
Add a controller/action for that route
In that action, fetch the data from the DB and render it in your preferred format
On the client-side, make the AJAX call to that controller/action and do something with the response.
I have a file object store by indexing name and library_id like below,
let objectStore = db.createObjectStore('file', { keyPath: 'id' });
tempStore.createIndex('nameLibId', ['attributes.name', 'attributes.library_id'], { unique: false });
The object store contains multiple library id's files. I'd like apply the name sort to the particular library id's files. I tried indexing in the below format but it returns empty data.
let self = this,
db = get(self, 'db'),
transaction = db.transaction(["file"], "readonly"),
objectStore = transaction.objectStore("file"),
index = objectStore.index('nameLibId'),
keyRange = IDBKeyRange.only('library_id')),
req = index.getAll(keyRange);
req.onsuccess = ((e)=>{
console.log(e.target.result); // returns empty array
});
Attached the screenshot of db model for reference.
24536475, abc, created, jhgf and lastmodified file names are belongs to a library id called 123.
Screen Shot..* file names are belongs to an another library id called 234.
I need the files which are sorted by name only the given library id. Any help would be highly appreciated.
If your index is based on a properties array and you want to match something using IDBKeyRange.only, then your parameter to IDBKeyRange.only should also be an array. Right now you are comparing a basic string value against a properties array value, where of course nothing matches. In other words, you cannot query against a two-part array using only one part of it.
Furthermore, the parameter to IDBKeyRange.only isn't a property name, it is a value. You want to specify a value to match in the index's set of keypath values. For example, if your index was based exclusively on attributes.name, then you would want to specify a particular value within that index, such as "abc".
And so, taking into account the above two points, and given that your index is not a single value but is instead an array of two properties, you need to revise your parameter to IDBKeyRange.only to look for an array. Something like IDBKeyRange.only(['abc', 'yoktc....']);.
Now, this is further complicated by the fact that what you are doing in your code does not actually accomplish what you want. Ignoring the sort concern for a moment, you only want to use the id condition, and not the name, when matching rows of this index. So you might be tempted to try IDBKeyRange.only([undefined, 'asdf']). Unfortunately this will not work at all because you cannot specify undefined (you will get a javascript error).
So, you must always query by both values, even though you only want to apply criteria to one of the values. The trick here is that you switch to using a different method than only. You use IDBKeyRange.bound(), and furthermore, you do a trick where you specify a criteria such as "smallest possible number is less than my number and my number is less than largest possible number", e.g. a condition that always is true. You use "smallest possible value" as your lower boundary, and "largest possible value" as your upper boundary.
Here is an example in your case. The smallest possible value of name I think is empty string. The largest possible value of name is probably any non-alphanumeric character, so let's use tilde "~". So, now we would rewrite the range parameter. Instead of using IDBKeyRange.only, we use IDBKeyRange.bound. It looks like the following (roughly):
var libId = ???;
var smallestNameValue = '';
var largestNameValue = '~';
var lowerBound = [smallestNameValue, libId];
var upperBOund = [largestNameValue, libId];
var range = IDBKeyRange.bound(lowerBound, upperBound);
Now, the second part, regarding sorting, and a major caveat of using indices that have multiple parts (not to be confused with the multiPart index property, ugh). And I myself get this backwards all the time, so I might even be wrong here and the above will work. The problem with the above is that one the first criterion is met the second is ignored, because of how the short-circuited array sorting algorithm works in indexedDB's comparison function. Your query is going to match everything, because every index row meets the criteria. So the trick to this is to always query first by the important condition, to basically pay attention to the order in which you specify your conditions. So what that means is that you need to switch the order of the properties you specified when creating the index, so that you can query first by libId and then by name.
Instead of createIndex('nameLibId',['attributes.name','attributes.library_id']); you want to do createIndex('nameLibId',['attributes.library_id', 'attributes.name']);. And this also means you need to swap your lower and upper bound queries, e.g. var lowerBound = [libId, smallestNameValue]; (and don't forget to switch the upper).
As I mentioned in my answer on using compound indices, you can always using indexedDB.cmp to experiment. Right now, open up the console on this web page. In the console, type something like this:
indexedDB.cmp(['', '5'], ['~', '5']);
Take a look at the results.
Some final notes:
Tilde might be the wrong thing to use, sorry but I am not bothering to remember, you could also just try any valid sentinel value, where by sentinel I mean any value you know will always come after all your other valid values
As I point out in my other answer, if either prop is missing in the data the actual object won't match
for cmp, -1 means left is less than right, 0 means left equals right, and 1 means left greater than right
I am adding rows in sequence in a script component. The sequence is such that I am parsing values from an input string then adding them to the output. This way all values from a particular input string are added before those from the next input string ( or so I assume).
Is this assumption incorrect?
I ask because I need to use the pivot transform (needs data sorted) after the script component and for performance reasons I would rather not add a sort between them.
So when I pivot on the original input string's identifier, will my pivot results be correct?
I needed a similar solution. Short answer is yes but this may depend on how you write your script task. Using the Input0Buffer buffer and calling .NextRow and then after what ever logic / processing you do, send the row to the one of your outputbuffers using AddRow. The operation becomes a synchronous row by row operation.