From 6104b9aedeb1668f24f704470c892b48108a869f Mon Sep 17 00:00:00 2001
From: Shigma <1700011071@pku.edu.cn>
Date: Fri, 23 Apr 2021 03:41:53 +0800
Subject: [PATCH] feat(mysql): support orm foreign key, fix #243

---
 packages/koishi-core/src/database.ts  | 7 +++++--
 packages/plugin-mysql/src/database.ts | 6 +++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/packages/koishi-core/src/database.ts b/packages/koishi-core/src/database.ts
index 55bf3490fa..c2cffa0d3c 100644
--- a/packages/koishi-core/src/database.ts
+++ b/packages/koishi-core/src/database.ts
@@ -17,15 +17,18 @@ export namespace Tables {
   export type Field<T extends TableType> = string & keyof Tables[T]
 
   interface Meta<O> {
+    type?: 'incremental'
     primary?: keyof O
     unique?: (keyof O)[]
-    type?: 'incremental'
+    foreign?: {
+      [K in keyof O]: [TableType, string]
+    }
   }
 
   export const config: { [T in TableType]?: Meta<Tables[T]> } = {}
 
   export function extend<T extends TableType>(name: T, meta?: Meta<Tables[T]>) {
-    config[name] = { primary: 'id', unique: [], type: 'incremental', ...meta } as any
+    config[name] = { primary: 'id', unique: [], type: 'incremental', foreign: {}, ...meta } as any
   }
 
   extend('user')
diff --git a/packages/plugin-mysql/src/database.ts b/packages/plugin-mysql/src/database.ts
index 8bb9149167..e888debe16 100644
--- a/packages/plugin-mysql/src/database.ts
+++ b/packages/plugin-mysql/src/database.ts
@@ -82,7 +82,7 @@ class MysqlDatabase {
         const cols = Object.keys(table)
           .filter((key) => typeof table[key] !== 'function')
           .map((key) => `${escapeId(key)} ${MysqlDatabase.Domain.definition(table[key])}`)
-        const { primary, unique } = KoishiTables.config[name as TableType]
+        const { primary, unique, foreign } = KoishiTables.config[name as TableType]
         cols.push(`primary key (${escapeId(primary)})`)
         for (const key of unique) {
           cols.push(`unique index (${escapeId(key)})`)
@@ -92,6 +92,10 @@ class MysqlDatabase {
             cols.push(`unique index (${escapeId(key)})`)
           }
         }
+        for (const key in foreign) {
+          const [table, key2] = foreign[key]
+          cols.push(`foreign key (${escapeId(key)}) references ${escapeId(table)} (${escapeId(key2)})`)
+        }
         logger.info('auto creating table %c', name)
         await this.query(`CREATE TABLE ?? (${cols.join(',')}) COLLATE = ?`, [name, this.config.charset])
       } else {