Hi I'm using NestJs with TypeOrm and currently connected to a MongoDB (but I want to be independent because most customers use MSSQL and Postgres databases).
Basically I want to store a key/value pair to the database. Both are of type String. This is the mapping entity holding the pair
#Entity()
export class Mapping extends BaseEntity {
#PrimaryColumn()
key: string;
#Column()
value: string;
}
The repository is currently empty
#EntityRepository(Mapping)
export class MappingsRepository extends Repository<Mapping> {}
In my service file I try to find a value by its key
public async getValueByKey(key: string): Promise<string> {
const mapping: Mapping = await this.mappingsRepository.findOne(key);
if (!mapping) {
throw new NotFoundException(`Key ${key} does not exist`);
}
return mapping.value;
}
Unfortunately the findOne function always throws this error when passing in a key
Argument passed in must be a single String of 12 bytes or a string of
24 hex characters
How can I fix this so that I can pass in any keys of type String? The parameter key is defined, I tried it with dummy values like f or ffsdagsdgfdg
Can you try
await this.mappingsRepository.findOne({key});
My guess it that typeorm doesn't understand primary key other than id
findOne for mongo means it will search document by property _id and not your key
because, mongo, by default, always add this _id as unique validator for each document
so, you should provide a query to that method like it is defined in itssajan answer
but i think your use case of TypeORM is not the best, because it is made to work with SQL dbs, and not NoSQL dbs
Related
I'm using the typescript-mongodb plugin to graphql-codegen to generate Typescript types for pulling data from MongoDB and outputting it via GraphQL on Node.
My input GraphQL schema looks like this
type User #entity{
id: ID #id,
firstName: String #column #map(path: "first_name"),
...
The generated output Typescript types look correct
export type User = {
__typename?: 'User',
id?: Maybe<Scalars['ID']>,
firstName?: Maybe<Scalars['String']>,
...
And the corresponding DB object
export type UserDbObject = {
_id?: Maybe<String>,
first_name: Maybe<string>,
...
The problem is when actually sending back the mongo document as a UserDbObject I do not get the fields mapped in the output. I could write a custom resolver that re-maps the fields back to the User type, but that would mean I'm mapping the fields in two different places.
i.e. I do not get mapped fields from a resolver like this
userById: async(_root: any, args: QueryUserByIdArgs, _context: any) : Promise<UserDbObject> => {
const result = await connectDb().then((db) => {
return db.collection<UserDbObject>('users').findOne({'_id': args.id}).then((doc) => {
return doc;
});
})
...
return result as UserDbObject;
}
};
Is there a way to use the typescript-mongodb plugin to only have to map these fields in the schema, then use the auto-generated code to resolve them?
You can use mappers feature of codegen to map between your GraphQL types and your models types.
See:
https://graphql-code-generator.com/docs/plugins/typescript-resolvers#mappers---overwrite-parents-and-resolved-values
https://graphql-code-generator.com/docs/plugins/typescript-resolvers#mappers-object
Since all codegen plugins are independent and not linked together, you should do it manually, something like:
config:
mappers:
User: UserDbObject
This will make typescript-resolvers plugin to use UserDbObject at any time (as parent value, or as return value).
If you wish to automate this, you can either use the codegen programmatically (https://graphql-code-generator.com/docs/getting-started/programmatic-usage), or you can also create a .js file instead of .yaml file that will create the config section according to your needs.
I am trying to access a table in my Secondary DB whose name I am obtaining from my Primary DB. My difficulty is to pass the "DB-Name" as a parameter into my secondary query, (BTW I am using MyBatis annotation based Mappers).
This is my Mapper
#SelectProvider(type = DealerQueryBuilder.class, method = "retrieveDealerListQuery")
#Results({
#Result(property="dealerID", column="frm_dealer_master_id"),
#Result(property="dealerTypeID", column="frm_dealer_type_id", one=#One(select="retrieveDealerTypeDAO")),
#Result(property="dealerName", column="frm_dealer_name")
})
public List<Dealer> retrieveDealerListDAO(#Param("firmDBName") String firmDBName);
#Select("SELECT * from ${firmDBName}.frm_dealer_type where frm_dealer_type_id=#{frm_dealer_type_id}")
#Results({
#Result(property="dealerTypeID", column="frm_dealer_type_id"),
#Result(property="dealerType", column="frm_dealer_type")
})
public DealerType retrieveDealerTypeDAO(#Param("firmDBName") String firmDBName, #Param("frm_dealer_type_id") int frm_dealer_type_id);
The firmDBName I have is obtained from my "Primary DB".
If I omit ${firmDBName} in my second query, the query is trying to access my Primary Database and throws out table "PrimaryDB.frm_dealer_type" not found. So it is basically trying to search for a table named "frm_dealer_type" in my Primary DB.
If I try to re-write the #Result like
#Result(property="dealerTypeID", column="firmDBName=firmDBName, frm_dealer_type_id=frm_dealer_type_id", one=#One(select="retrieveDealerTypeDAO")),
It throws an error that Column"firmDBName" does not exist.
Changing ${firmDBName} to #{firmDBName} also did not help.
I did refer to this blog - here
I want a solution to pass my parameter firmDBName from my primary query into secondary query.
The limitation here is that your column must be returned by the first #SELECT.
If you look at the test case here you will see that parent_xxx values returned by the first Select.
Your DealerQueryBuilder must select firmDBName as a return value and your column must map the name of the return column to that.
Your column definition is always wrong, it should be:
{frm_dealer_type_id=frm_dealer_type_id,firmDBName=firmDBName} or whatever it was returned as from your first select.
Again you can refer to the test case I have above as well as the documentation here http://www.mybatis.org/mybatis-3/sqlmap-xml.html#Nested_Select_for_Association
I have an Entity with a String field (storing JSON), and need to compare value from its database column with another value. Problem is that type of this database column is TEXT, but in fact it contains JSON. So, is there a way to write something like this? I.e. I need to compare my value with some field of JSON from TEXT column.
criteriaBuilder.equal(root.get("json_column").customExpressionn(new Expression{
Object handle(Object data){
return ((Object)data).get("json_field")
}
}), value)
Assuming, you have a MySQL server with version > 5.7.x
I just had the same issue. I wanted to find all entities of a class that had a JSON field value inside a JSON object column.
The solution that worked for me was something along the lines (sorry typing from a phone)
(root, query, builder)->{
return builder.equal(
builder.function("JSON_EXTRACT", String.class, root.get("myEntityJsonAttribute"), builder.literal("$.json.path.to.json.field")),
"searchedValueInJsonFieldOfJsonAttribute"
)
}
I have a base class Entity that has a string Id member and a derived class A.
But when creating a new instance of the derived class and using InsertOneAsync to add it to my collection, the document is added to the database with null as the Id value.
Using an ObjectId as the Id does seem to work, but I'm trying to prevent MongoDB dependency in my models.
I also experimented with the following code, but the results are the same:
BsonClassMap.RegisterClassMap<Entity>(cm =>
{
cm.MapIdField(x => x.Id).SetSerializer(new StringSerializer(BsonType.ObjectId));
});
I had the same issue and finally got it to work (with the 2.0 driver) with these attributes:
[BsonId]
[BsonRepresentation(BsonType.ObjectId)]
[BsonIgnoreIfDefault]
Or the equivalent BsonClassMap fluent interface:
BsonClassMap.RegisterClassMap<Entity>(cm =>
{
cm.MapIdField(x => x.Id)
.SetSerializer(new StringSerializer(BsonType.ObjectId))
.SetIgnoreIfDefault(true);
});
I tried to get the same working with .ReplaceOneAsync with Upsert on but that always leaves the id still null
Are you trying not to use ObjectID in your model. The ID doesn't have to be an objectID. You can decorate a string field as ID.
I have used string property with [BsonId] attribute without any issues.
I am querying a collection that includes an integer value among it's values, and loading resulting documents into this struct:
type Subscription struct {
Id bson.ObjectId "_id,omitempty"
Listen string
Job string
TimeoutSeconds int
Data string
}
var subscription Subscription
subscriptions := subscriptionsCol.Find(bson.M{"listen": "example_channel"}).Iter()
for subscriptions.Next(&subscription) {
log("Pending job: %s?%s (timeout: %d)\n",
subscription.Job,
subscription.Data,
subscription.TimeoutSeconds)
}
This is what phpMoAdmin shows me:
[_id] => MongoId Object (
[$id] => 502ed8d84eaead30a1351ea7
)
[job] => partus_test_job_a
[TimeoutSeconds] => 30
[listen] => partus.test
[data] => a=1&b=9
It puzzles me that subscription.TimeoutSeconds contains always 0, when I'm positive I have 30 in the document I inserted in the collection.
All other values are retrieved OK.
What's wrong with the int type?
Have you tried setting the "key" value for that field?
Unmarshal
The lowercased field name is used as the key for each exported field,
but this behavior may be changed using the respective field tag.
type Subscription struct {
Id bson.ObjectId "_id,omitempty"
Listen string
Job string
TimeoutSeconds int "TimeoutSeconds"
Data string
}
The other fields are working fine because their lowercase value matches your Mongo fields in the collection, whereas TimeoutSeconds is using the TitleCase. What is happening is the int field is being left at its zero value, since the Unmarshal can't map a field to it.
When UnMarshalling data, there are multiple keys that are supported.
Below are some examples:
type T struct {
A bool
B int "myb"
C string "myc,omitempty"
D string `bson:",omitempty" json:"jsonkey"`
E int64 ",minsize"
F int64 "myf,omitempty,minsize"
}
The general spec for 1 key-value pair during marshal is :
"[<key>][,<flag1>[,<flag2>]]"
`(...) bson:"[<key>][,<flag1>[,<flag2>]]" (...)`
GO provides support for particular keywords like bson (for mongo keys) and json for setting the json key in a resposne.
Check the Marshal GO Reference for more information.
Similarly there are some frameworks which provide further options to define the keys befor parsing. For example, in sql jinzhu github library gives support for setting default values, column ids to map, etc.
Anyone can use this feature and provide customized support.