where can i learn more abt creating database markup in yaml and data fixtures.
i followed a tutorial and they create a relationship like so: under relations in both User and Car. my qn is why is 'type: many' in Car. can i have it in User instead (just curious)?
abt data types. different database have different database support. i thought that in MySQL (InnoDB as used here) integer shld be tinyint(x), bigint(x), int(x) ... or string shld be varchar not string? isit not strict what i shld use here?
options:
type: INNODB
collate: utf8_general_ci
charset: utf8
User:
columns:
id:
type: integer
primary: true
autoincrement: true
name: string(300)
email: string(300)
phone: string(9)
car_id: integer
relations:
Car:
local: car_id
foreign: id
Car:
columns:
id:
type: integer
primary: true
autoincrement: true
brand: string(300)
relations:
Users:
class: User
foreign: car_id
local: id
type: many
UPDATE 1
"it is only necessary to specify the relationship on the end where the foreign key exists" in my example, that will be? do they mean the FK table (car) or the FK column (user)?
i dont see TEXT data type, is that clob (Character Large OBject)? – iceangel89 0 secs ago [delete this comment]
what is foreignAlias? is there a alias too?
UPDATE 2
this will be abit long, i just wish to clarify some of the code examples in the Doctrine YAML Schema Files docs page. focus on the relationships section -> in // comments
User:
columns:
username:
type: string(255)
password:
type: string(255)
contact_id:
type: integer
relations:
Contact:
class: Contact // if the table is named Contact, class will be Contact also?
local: contact_id
foreign: id
foreignAlias: User // whats alias for?
foreignType: one // one contact ... to ...
type: one // one user?
Contact:
columns:
first_name:
type: string(255)
last_name:
type: string(255)
phone:
type: string(255)
email:
type: string(255)
address:
type: string(255)
relations:
User:
class: User
local: id
foreign: contact_id
foreignAlias: Contact
foreignType: one
type: one
regarding the many to many example, what does the following mean?
attributes:
export: all
validate: true
tableName: group_table
refClass: GroupUser
where can i learn more abt creating database markup in yaml and data fixtures.
Doctrine manual, “YAML schema files” and “Data Fixtures” chapters.
can i have it in User instead (just curious)?
Yes, but this section will be called foreignType then. Here, an example:
User:
columns:
id:
type: integer
primary: true
autoincrement: true
name: string(300)
email: string(300)
phone: string(9)
car_id: integer
relations:
Car:
local: car_id
foreign: id
foreignType: many
abt data types...
Well, Doctrine column types and database column types are “slightly” different. Just compare list of Doctrine column types and, say, MySQL's one.
I know this is old, but these are things I've found confusing, and still do. In fact I'm not expert in all the possibilities, this is just based on what works for me. I think you may be looking for many-to-many relations, but I completely avoid the Doctrine support for them, and instead define my own association tables explicitly, so I only ever use one-to-many and one-to-one relations.
As noted in UPDATE1, you only specify the relationship on the end that has the foreign key.
In this case, User has a column car_id that is a foreign key that
refers to the id column of Car. So on the User end, the relation
is with Car, the local column containing the key value is
car_id, and the column in the other (foreign) table to which it refers is id.
Doctrine defines its own data types, and automatically maps them
onto the data types of the particular database you are using.
develop7 gave links to the documentation, or you can look in the
doctrine sources.
foreignAlias gives a name to the relation on the foreign side.
There is no alias because the name of the relation on the side
containing the foreign key is given by the name used at the level
below relations:, which is commonly specified as the name of the
table to which the foreign key refers.
Regarding UPDATE 2:
class: Contact The yaml for User says that it has a relation named Contact which refers to the class Contact. By default, class names and table names are the same; the yaml schema deals only with class names, though it is possible to tell it to use a different table name for a given class.
foreignAlias: User The name of the relation from Contact to User is "User". As explained above, there is nothing called "alias", the name of the relation from User to Contact is "Contact", because that's the name in the list of relations for User under which this line appears. Of course these default relation namings fall apart if you happen to have more than one relationship between the same two classes; you need the ability to give explicit relation names that differ from the class names. The names of relations are important because you use them in DQL joins.
foreignType: one A Contact (the foreign side) has one User
type: one A User (the local side) has one Contact.
Note that this example is a little unusual in showing explicitly both sides of the same relation. Normally, you'd show it only on the side containing the foreign key (the User side). Since a User contains a foreign key pointing to a Contact, the "type" can only be "one". But the foreignType could be "many", indicating that a given Contact could be pointed-to by many Users, though in this case it is specified that only one User can refer to a given Contact.
I don't actually know what would happen if you specified the type as "many". Implementing that would require an extra association table like many-to-many relations do, and I don't happen to know if Doctrine would create such a table "automatically" as it does for many-to-many relations. For my use of Doctrine, I avoid implicit machinery based on naming conventions that I don't understand as much as possible, so I turn off "detect_relations" and avoid many-to-many relations.
Related
I'm using Amplify from AWS to build a small ecommerce project using React as frontend.
I'd like to know how I should write the "Product" and "Order" types in the schema in order to be able to write productId's to a product array in the Order table when users complete a purchase.
My schema.graphql file:
type Product #model {
id: ID!
name: String!
price: Int!
category: String!
images: [String]!
}
type Order #model {
id: ID!
products: [Product] #connection
}
My question is about the last line, do I need to define that [Product] connection there or I can use [String] to store product id's in a simple string array?
Point 1: In dynamoDB, you only need to define the data type of your partition key and sort key, and these can be string, number etc. For all the other attributes, you don't need to define anything.
Point 2: The dynamoDB designers prefer using a single table per application, unless it's impossible to manage data without multiple tables. Keeping this in mind, your table can be something like this.
Please observe: Only Id aka partition key and Sk aka sort key column is fixed here, all other columns can be anything per item. This is the beauty of DynamoDB. Refer to this document for dynamoDB supported data types.
I'm pondering a rebuild of a meal seating assignment app. I'll make use of GraphQL to query for attendees and their guests of a table at a meal event (assigned seating). The delivered data model looks something like this:
meal event 1
table A
attendee 1
guest 1
...
meal event 2
table L
attendee 1 (no guest this time)
...
An attendee may attend multiple meal events e.g. at a multi-day conference. That attendee may have a guest(s) at meal event(s). This could be another attendee record (two meal tickets, same info), noted as a guest however as an attendee and their guest(s) need to be seated at the same table (don't want spouse on other side of the room for example). Attendees will usually have the same guest(s) at multiple events, however not always due to cost or conflicting guest commitments or wanting to rotate guests per meal, etc.
How would I model this in a GraphQL schema? In the database I'd use join tables. However for client-facing GraphQL queries and schema types, I need to model this a bit differently (I think?). Here's what I have so far:
type Attendee {
name: String
** Can't add guests here as this may change per event
}
type Event {
name: String
tables: [Table]
}
type Table {
name: String
attendees: [Attendee]
** How do I "tree" in guests here for attendees for this table?
}
At this point do I need a join type to get guests per attendee per table per event?
When writing our server code, we typically encapsulate our business logic inside domain models like Event, Table, Attendee or Guest. However, these domain models don't have to have a strict one-to-one mapping with the tables we use to persist their data -- for example, an individual model might aggregate data from multiple tables.
Similarly, your GraphQL types do not have to have a one-to-one mapping to your domain models. It can often make sense to represent the same domain model as multiple types. For example, we can do something like:
type EventAttendee {
id: ID!
name: String!
}
type TableAttendee {
id: ID!
name: String!
guests: [Guest!]!
}
type Table {
id: ID!
attendees: [TableAttendee!]!
}
type Event {
id: ID!
name: String!
attendees: [EventAttendee!]!
tables: [Table!]!
}
Your schema effectively represents multiple graphs or views of your data. Depending on where on that graph your domain model ends up should determine what fields it exposes as a type -- in some contexts, exposing certain properties or relationships makes sense, in others it does not.
I have this game type:
type Game {
id: ID! #id
goals: [Goal]
}
which have a Goal relationship to:
type Goal {
id: Int! #id(strategy: SEQUENCE) #sequence(name: "IncID", initialValue: 1, allocationSize: 20)
thumbnail: String!
player: String!
minute: Int!
}
what i'm trying to do by that "id" mess is to create an incremental id value for the goal, for the purpose of creating a url for each goal, like this:
domaine.com/game/{id-of-the-game}/goal/{incremental-id(1,2..)}
the problem is, the Goal type looks like it is an entity of its own, it is gonna keep the last incremented id even if it is new game.
so i want to reset the id sequence for each new game.
What you ask for is not possible using the #id annotation. Each type in the prisma model needs to have a unique id to identify the object in the database. If the underlying database used is MongoDB there will be a Goal collection with documents in it, each representing an individual Goal identified by the id. If the underlying database used is MySQL/PostgreSQL the Goals will be stored in a Goal table with each row representing an individual Goal.
Each individual object (no matter if it is stored as a document or row) needs to be uniquely identified to access it and to create relations, e.g. between Goal objects and Game objects.
If the Goal id would start at 1 for each Game this would violate the unique constraint for the id field since two Goals in the table or collection would be identified by the same id (e.g. 1).
What I would suggest is to simply add something like a "numberInGame" field to the Goal type and fill it while creating the Goal (e.g. by taking goals.length in the Game.type into consideration).
Hope that helped to clarify the id field uniqueness constraint.
I'm using Doctrine2 with codeIgniter, I've created some models in yml format. Using command line I've created the Proxies and Entities. When I'm trying to create the database tables, I'm getting the following error:
[Doctrine\ORM\Mapping\MappingException]
Invalid mapping file 'Entities.category.dcm.yml' for class
'Entities\category'.
Here's Entities.category.dcm.yml:
Entities\Category:
type: entity
table: categories
fields:
id:
type: integer
id: true
generator:
strategy: AUTO
name:
type: string
length: 50
nullable: false
description:
type: string
length: 255
First of all, check the paths configured for your entities and for the YML mapping driver.
Also, your Entities.category.dcm.yml contains mappings for Entities\Category, and not Entities\category.
As you can see in the base FileDriver Doctrine ORM does direct matching for mapped classes, and applies no normalization on the class names. Category and category are therefore different.
I have a site that is for a video game I play and am working on improving the performance of the site by implementing some additional caching. I've already been able to implement query result caching on custom repository functions, but haven't been able to find anywhere that explains how I can include query result caching on the built in functions (findOneById, etc). I'm interested in doing this because many of my database queries are executed from these 'native' repository functions.
So as an example I have a character entity object with the following properties: id, name, race, class, etc.
Race and class in this object are references to other entity objects for race and class.
When I load a character for display I get the character by name (findOneByName) and then in my template I display the character's race/class by $characterObject->getRace()->getName(). These method calls in the template result in a query being run on my Race/Class entity tables fetching the entity by id (findOneById I assume).
I've attempted to create my own findOneById function in the repository, but it is not called under these circumstances.
How can I setup doctrine/symfony such that these query results are cache-able?
I am running Symfony 2.1.3 and doctrine 2.3.x
I've found out that it isn't possible to enable query cache on doctrine build in functions. I will post a link which explains why later after I find it again.
Your entities probably look something like this:
MyBundle\Entity\Character:
type: entity
table: Character
fields:
id:
id: true
type: bigint
name:
type: string
length: 255
manyToOne:
race:
targetEntity: Race
joinColumns:
raceId:
referencedColumnName: id
MyBundle\Entity\Race:
type: entity
table: Race
fields:
id:
id: true
type: bigint
name:
type: string
length: 255
oneToMany:
characters:
targetEntity: Character
mappedBy: race
If that's the case, then modify your Character entity mapping so that it eagerly loads the Race entity as well:
MyBundle\Entity\Character:
...
manyToOne:
race:
targetEntity: Race
joinColumns:
raceId:
referencedColumnName: id
fetch: EAGER
Doctrine documentation on the fetch option: #ManyToOne