feat(orm): support evaluatation api

koishijs · Aug 21, 2021 · 9172e95 · 9172e95
1 parent 3cad36f
commit 9172e95
Show file tree

Hide file tree

Showing 2 changed files with 76 additions and 44 deletions.
diff --git a/packages/koishi-core/src/database.ts b/packages/koishi-core/src/database.ts
@@ -212,12 +212,47 @@ export namespace Query {
     return modifier || {}
   }
 
+  type Projection<T extends TableType, K extends string> = Record<K, Evaluation.Aggregation<Tables[T]>>
+
   export interface Database {
+    drop(table?: TableType): Promise<void>
     get<T extends TableType, K extends Field<T>>(table: T, query: Query<T>, modifier?: Modifier<K>): Promise<Pick<Tables[T], K>[]>
     remove<T extends TableType>(table: T, query: Query<T>): Promise<void>
     create<T extends TableType>(table: T, data: Partial<Tables[T]>): Promise<Tables[T]>
     update<T extends TableType>(table: T, data: Partial<Tables[T]>[], key?: Index<T>): Promise<void>
-    drop(table?: TableType): Promise<void>
+    aggregate<T extends TableType, K extends string>(table: T, fields: Projection<T, K>, query?: Query<T>): Promise<Record<K, number>>
+  }
+}
+
+export namespace Evaluation {
+  export type Numeric<T = any, U = never> = U | number | Keys<T, number> | NumericExpr<Numeric<T, U>>
+
+  export interface NumericExpr<N = Numeric> {
+    $add?: N[]
+    $multiply?: N[]
+    $subtract?: [N, N]
+    $divide?: [N, N]
+  }
+
+  export type Boolean<T = any, U = never> = U | boolean | Keys<T, boolean> | BooleanExpr<Numeric<T, U>>
+
+  export interface BooleanExpr<N = Numeric> {
+    $eq?: [N, N]
+    $ne?: [N, N]
+    $gt?: [N, N]
+    $gte?: [N, N]
+    $lt?: [N, N]
+    $lte?: [N, N]
+  }
+
+  export type Aggregation<T = any> = Numeric<{}, AggregationExpr<Numeric<T>>>
+
+  export interface AggregationExpr<N = Numeric> {
+    $sum?: N
+    $avg?: N
+    $max?: N
+    $min?: N
+    $count?: N
   }
 }
 

diff --git a/packages/plugin-mysql/src/index.ts b/packages/plugin-mysql/src/index.ts
@@ -1,5 +1,5 @@
-import MysqlDatabase, { Config, TableType } from './database'
-import { User, Channel, Database, Context, Query } from 'koishi-core'
+import MysqlDatabase, { Config } from './database'
+import { User, Channel, Database, Context, Query, Evaluation } from 'koishi-core'
 import { difference } from 'koishi-utils'
 import { OkPacket, escapeId, escape } from 'mysql'
 import * as Koishi from 'koishi-core'
@@ -74,50 +74,47 @@ const queryOperators: QueryOperators = {
   $bitsAnyClear: (key, value) => `${key} & ${escape(value)} != ${escape(value)}`,
 }
 
-export function createFilter<T extends TableType>(name: T, query: Query<T>) {
-  function parseQuery(query: Query.Expr) {
-    const conditions: string[] = []
-    for (const key in query) {
-      // logical expression
-      if (key === '$not') {
-        conditions.push(`!(${parseQuery(query.$not)})`)
-        continue
-      } else if (key === '$and') {
-        if (!query.$and.length) return '0'
-        conditions.push(...query.$and.map(parseQuery))
-        continue
-      } else if (key === '$or' && query.$or.length) {
-        conditions.push(`(${query.$or.map(parseQuery).join(' || ')})`)
-        continue
-      }
+function parseQuery(query: Query.Expr) {
+  const conditions: string[] = []
+  for (const key in query) {
+    // logical expression
+    if (key === '$not') {
+      conditions.push(`!(${parseQuery(query.$not)})`)
+      continue
+    } else if (key === '$and') {
+      if (!query.$and.length) return '0'
+      conditions.push(...query.$and.map(parseQuery))
+      continue
+    } else if (key === '$or' && query.$or.length) {
+      conditions.push(`(${query.$or.map(parseQuery).join(' || ')})`)
+      continue
+    }
 
-      // query shorthand
-      const value = query[key]
-      const escKey = escapeId(key)
-      if (Array.isArray(value)) {
-        conditions.push(createMemberQuery(escKey, value))
-        continue
-      } else if (value instanceof RegExp) {
-        conditions.push(createRegExpQuery(escKey, value))
-        continue
-      } else if (typeof value === 'string' || typeof value === 'number' || value instanceof Date) {
-        conditions.push(createEqualQuery(escKey, value))
-        continue
-      }
+    // query shorthand
+    const value = query[key]
+    const escKey = escapeId(key)
+    if (Array.isArray(value)) {
+      conditions.push(createMemberQuery(escKey, value))
+      continue
+    } else if (value instanceof RegExp) {
+      conditions.push(createRegExpQuery(escKey, value))
+      continue
+    } else if (typeof value === 'string' || typeof value === 'number' || value instanceof Date) {
+      conditions.push(createEqualQuery(escKey, value))
+      continue
+    }
 
-      // query expression
-      for (const prop in value) {
-        if (prop in queryOperators) {
-          conditions.push(queryOperators[prop](escKey, value[prop]))
-        }
+    // query expression
+    for (const prop in value) {
+      if (prop in queryOperators) {
+        conditions.push(queryOperators[prop](escKey, value[prop]))
       }
     }
-
-    if (!conditions.length) return '1'
-    if (conditions.includes('0')) return '0'
-    return conditions.join(' && ')
   }
-  return parseQuery(Query.resolve(name, query))
+
+  if (!conditions.length) return '1'
+  if (conditions.includes('0')) return '0'
+  return conditions.join(' && ')
 }
 
 Database.extend(MysqlDatabase, {
@@ -131,7 +128,7 @@ Database.extend(MysqlDatabase, {
   },
 
   async get(name, query, modifier) {
-    const filter = createFilter(name, query)
+    const filter = parseQuery(Query.resolve(name, query))
     if (filter === '0') return []
     const { fields, limit, offset } = Query.resolveModifier(modifier)
     const keys = this.joinKeys(this.inferFields(name, fields))
@@ -142,7 +139,7 @@ Database.extend(MysqlDatabase, {
   },
 
   async remove(name, query) {
-    const filter = createFilter(name, query)
+    const filter = parseQuery(Query.resolve(name, query))
     if (filter === '0') return
     await this.query('DELETE FROM ?? WHERE ' + filter, [name])
   },