The schema.prisma
file defines the data models, relationships, and database connection details for Prisma. When using different databases like MongoDB and MySQL, the schema.prisma
file will have differences due to the unique characteristics and data types of each database.
Key Differences Between schema.prisma
for MongoDB and MySQL
1. Datasource Configuration
The datasource
block specifies the database provider (mongodb
or mysql
) and connection details. The provider will change depending on the database you are using.
- MongoDB Configuration:
datasource db {
provider = "mongodb"
url = env("DATABASE_URL")
}
- MySQL Configuration:
datasource db {
provider = "mysql"
url = env("DATABASE_URL")
}
2. Data Model Differences
MongoDB and MySQL have different data types and ways of defining primary keys and relationships. Here are the primary differences:
-
Primary Key Definition:
- In MongoDB, the primary key is usually an
ObjectId
and is mapped using the@map("_id")
directive. - In MySQL, the primary key is typically an integer with auto-increment.
- In MongoDB, the primary key is usually an
-
Data Type Differences:
-
MongoDB supports data types like
String
,Int
,Float
,Boolean
,DateTime
, and custom types likeJson
andObjectId
. -
MySQL has a more structured type system, including
Int
,Float
,Double
,Boolean
,DateTime
,Decimal
, andString
.
-
MongoDB supports data types like
Example of schema.prisma
for MongoDB:
datasource db {
provider = "mongodb"
url = env("DATABASE_URL")
}
generator client {
provider = "prisma-client-js"
}
model User {
id String @id @default(auto()) @map("_id") @db.ObjectId
name String
email String @unique
posts Post[]
}
model Post {
id String @id @default(auto()) @map("_id") @db.ObjectId
title String
content String
published Boolean @default(false)
authorId String @db.ObjectId
author User? @relation(fields: [authorId], references: [id])
}
Example of schema.prisma
for MySQL:
datasource db {
provider = "mysql"
url = env("DATABASE_URL")
}
generator client {
provider = "prisma-client-js"
}
model User {
id Int @id @default(autoincrement()) // Integer auto-increment primary key
name String
email String @unique
posts Post[]
}
model Post {
id Int @id @default(autoincrement())
title String
content String
published Boolean @default(false)
authorId Int
author User @relation(fields: [authorId], references: [id])
}
Summary of Differences
Feature | MongoDB (schema.prisma ) |
MySQL (schema.prisma ) |
---|---|---|
Datasource Provider | provider = "mongodb" |
provider = "mysql" |
Primary Key Definition | id String @id @default(auto()) @map("_id") @db.ObjectId |
id Int @id @default(autoincrement()) |
Data Types | Supports String , Int , Float , Boolean , DateTime , etc. |
More structured, includes Int , Float , Double , etc. |
Foreign Key Relationship | Foreign keys defined with @db.ObjectId
|
Foreign keys with Int or other standard SQL types |
Autoincrement ID | Not applicable (@default(auto()) ) |
@default(autoincrement()) |
Unique Identifier |
@unique for unique fields |
@unique for unique fields |
Conclusion
The main differences in the schema.prisma
file between MongoDB and MySQL revolve around how primary keys are handled, the differences in data types, and the way relationships and fields are mapped to the database. When switching from MongoDB to MySQL, these differences must be adjusted to accommodate the underlying database system's constraints and data modeling.
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