prisma Order by relation 只有_count 属性。不能按关系字段排序
prisma Order by relation has only _count property. Can not order by relation fields
考虑以下 Prisma 架构:
model Conversation {
id Int @id @default(autoincrement())
createdAt DateTime @db.Timestamp(6)
messages ConversationMessage[]
}
model ConversationMessage {
id Int @id @default(autoincrement())
text String @db.VarChar(1000)
sentAt DateTime @map("sent_at") @db.Timestamp(6)
conversationId Int? @map("conversation_id")
userId Int? @map("user_id")
conversation Conversation? @relation(fields: [conversationId], references: [id])
sender User? @relation(fields: [userId], references: [id])
}
我想 运行 这样的查询,以便我得到一个按消息日期排序的对话列表,即首先有新消息的对话。
prisma.conversation.findMany({
orderBy: {
messages: {
sentAt: 'desc'
}
},
...
})
但是我现在可以查询的唯一方法是这样的,即关系只有 _count
属性 不知何故。
prisma.conversation.findMany({
orderBy: {
messages: {
'_count': 'desc'
}
},
...
})
环境与设置
OS: Mac OS,
Database: PostgreSQL
Node.js version: v12.19.0
Prisma 版本
prisma : 2.24.1
@prisma/client : 2.24.1
Current platform : darwin
Query Engine : query-engine 18095475d5ee64536e2f93995e48ad800737a9e4 (at node_modules/@prisma/engines/query-engine-darwin)
Migration Engine : migration-engine-cli 18095475d5ee64536e2f93995e48ad800737a9e4 (at node_modules/@prisma/engines/migration-engine-darwin)
Introspection Engine : introspection-core 18095475d5ee64536e2f93995e48ad800737a9e4 (at node_modules/@prisma/engines/introspection-engine-darwin)
Format Binary : prisma-fmt 18095475d5ee64536e2f93995e48ad800737a9e4 (at node_modules/@prisma/engines/prisma-fmt-darwin)
Default Engines Hash : 18095475d5ee64536e2f93995e48ad800737a9e4
Studio : 0.397.0
Preview Features : orderByRelation
谢谢!
OrderBy 关系仍然是一个预览功能 - 您需要确保使用功能标志
generator client {
provider = "prisma-client-js"
previewFeatures = ["orderByRelation"]
}
虽然 Prisma V2.19 引入了 sort by relation aggregate value,但截至撰写本文时,唯一支持的聚合 属性 是 count
。据我所知,目前 Prisma 不直接支持您的要求。如果他们添加 min
和 max
聚合属性进行排序,那将是可能的。
一种可能的解决方法是在检索后对 Node.js 中的邮件进行排序。我正在添加一个解决方案,该解决方案使用 orderByRelation
预览功能来简化排序并确保对话中的消息始终有序(最新的优先)。
正在更新 Prisma 客户端以使用 orderByRelation
预览功能。
首先,更新schema.prisma
以添加预览功能
generator client {
provider = "prisma-client-js"
previewFeatures = ["orderByRelation"]
}
现在更新 prisma 客户端
prisma generate client
获取 conversations
并按最新消息排序
// Assuming inside an async function
let unsortedConversations = await prisma.conversation.findMany({
include: {
messages: {
orderBy: {
sentAt: 'desc' // messages for each converastion will be ordered newest first.
}
}
},
// other conditions
})
unsortedConversations
包含所有必需的对话,但它们是无序的。您可以通过创建自定义比较器函数按所需顺序对其进行排序。
function conversationComparatorFunction(conversationA, conversationB) {
// Conversations with 0 messages will be placed last in arbitrary order.
if (!conversationB.messages.length) return 1;
if (!conversationA.messages.length) return -1;
// sort conversations based on sentAt date of the first message.
// since messages were previously sorted, messages[0] always contain the most recent message.
if (conversationA.messages[0].sentAt > conversationB.messages[0].sentAt) {
return -1;
} else if (conversationA.messages[0].sentAt < conversationB.messages[0].sentAt) {
return 1;
} else return 0;
}
let sortedConversations = unsortedConversations.sort(conversationComparatorFunction)
请注意,如果 Conversation
记录的数量 非常多 ,那么在应用程序端进行大排序可能会导致性能不佳,尤其是考虑到 Node.js是单线程的。
如果启用此预览功能,现在可以按一对多关系排序:
One-to-Many
For one-to-many relationships, you can order by the relation from one side:
✅ Order posts by their author's name
⛔️ Order authors by their post's titles
model Author {
id Int @id
name String
posts Post[]
}
model Post {
id Int @id
title String
author Author
}
prisma.post.findMany({
orderBy: [{
author: {
name: 'asc'
}
}]
})
考虑以下 Prisma 架构:
model Conversation {
id Int @id @default(autoincrement())
createdAt DateTime @db.Timestamp(6)
messages ConversationMessage[]
}
model ConversationMessage {
id Int @id @default(autoincrement())
text String @db.VarChar(1000)
sentAt DateTime @map("sent_at") @db.Timestamp(6)
conversationId Int? @map("conversation_id")
userId Int? @map("user_id")
conversation Conversation? @relation(fields: [conversationId], references: [id])
sender User? @relation(fields: [userId], references: [id])
}
我想 运行 这样的查询,以便我得到一个按消息日期排序的对话列表,即首先有新消息的对话。
prisma.conversation.findMany({
orderBy: {
messages: {
sentAt: 'desc'
}
},
...
})
但是我现在可以查询的唯一方法是这样的,即关系只有 _count
属性 不知何故。
prisma.conversation.findMany({
orderBy: {
messages: {
'_count': 'desc'
}
},
...
})
环境与设置
OS: Mac OS,
Database: PostgreSQL
Node.js version: v12.19.0
Prisma 版本
prisma : 2.24.1
@prisma/client : 2.24.1
Current platform : darwin
Query Engine : query-engine 18095475d5ee64536e2f93995e48ad800737a9e4 (at node_modules/@prisma/engines/query-engine-darwin)
Migration Engine : migration-engine-cli 18095475d5ee64536e2f93995e48ad800737a9e4 (at node_modules/@prisma/engines/migration-engine-darwin)
Introspection Engine : introspection-core 18095475d5ee64536e2f93995e48ad800737a9e4 (at node_modules/@prisma/engines/introspection-engine-darwin)
Format Binary : prisma-fmt 18095475d5ee64536e2f93995e48ad800737a9e4 (at node_modules/@prisma/engines/prisma-fmt-darwin)
Default Engines Hash : 18095475d5ee64536e2f93995e48ad800737a9e4
Studio : 0.397.0
Preview Features : orderByRelation
谢谢!
OrderBy 关系仍然是一个预览功能 - 您需要确保使用功能标志
generator client {
provider = "prisma-client-js"
previewFeatures = ["orderByRelation"]
}
虽然 Prisma V2.19 引入了 sort by relation aggregate value,但截至撰写本文时,唯一支持的聚合 属性 是 count
。据我所知,目前 Prisma 不直接支持您的要求。如果他们添加 min
和 max
聚合属性进行排序,那将是可能的。
一种可能的解决方法是在检索后对 Node.js 中的邮件进行排序。我正在添加一个解决方案,该解决方案使用 orderByRelation
预览功能来简化排序并确保对话中的消息始终有序(最新的优先)。
正在更新 Prisma 客户端以使用 orderByRelation
预览功能。
首先,更新schema.prisma
以添加预览功能
generator client {
provider = "prisma-client-js"
previewFeatures = ["orderByRelation"]
}
现在更新 prisma 客户端
prisma generate client
获取 conversations
并按最新消息排序
// Assuming inside an async function
let unsortedConversations = await prisma.conversation.findMany({
include: {
messages: {
orderBy: {
sentAt: 'desc' // messages for each converastion will be ordered newest first.
}
}
},
// other conditions
})
unsortedConversations
包含所有必需的对话,但它们是无序的。您可以通过创建自定义比较器函数按所需顺序对其进行排序。
function conversationComparatorFunction(conversationA, conversationB) {
// Conversations with 0 messages will be placed last in arbitrary order.
if (!conversationB.messages.length) return 1;
if (!conversationA.messages.length) return -1;
// sort conversations based on sentAt date of the first message.
// since messages were previously sorted, messages[0] always contain the most recent message.
if (conversationA.messages[0].sentAt > conversationB.messages[0].sentAt) {
return -1;
} else if (conversationA.messages[0].sentAt < conversationB.messages[0].sentAt) {
return 1;
} else return 0;
}
let sortedConversations = unsortedConversations.sort(conversationComparatorFunction)
请注意,如果 Conversation
记录的数量 非常多 ,那么在应用程序端进行大排序可能会导致性能不佳,尤其是考虑到 Node.js是单线程的。
如果启用此预览功能,现在可以按一对多关系排序:
One-to-Many
For one-to-many relationships, you can order by the relation from one side:
✅ Order posts by their author's name
⛔️ Order authors by their post's titles
model Author {
id Int @id
name String
posts Post[]
}
model Post {
id Int @id
title String
author Author
}
prisma.post.findMany({
orderBy: [{
author: {
name: 'asc'
}
}]
})