feat(db): 新增 exchange_rates 汇率表，支持联合主键与基础交叉汇率数据

src/actions/exchange.ts

@@ -0,0 +1,68 @@
+'use server';
+
+import { db } from '@/db';
+import { exchangeRates } from '@/db/schema';
+import { eq } from 'drizzle-orm';
+import { z } from 'zod';
+
+const updateExchangeRateSchema = z.object({
+  from: z.string().min(1).max(10),
+  to: z.string().min(1).max(10),
+  rate: z.string().min(1),
+});
+
+export async function updateExchangeRate(
+  from: string,
+  to: string,
+  rate: string,
+) {
+  const validation = updateExchangeRateSchema.safeParse({ from, to, rate });
+  if (!validation.success) {
+    return { success: false, error: 'Invalid input' };
+  }
+
+  try {
+    await db
+      .insert(exchangeRates)
+      .values({
+        fromCurrency: validation.data.from.toUpperCase(),
+        toCurrency: validation.data.to.toUpperCase(),
+        rate: validation.data.rate,
+      })
+      .onConflictDoUpdate({
+        target: [exchangeRates.fromCurrency, exchangeRates.toCurrency],
+        set: {
+          rate: validation.data.rate,
+          updatedAt: new Date(),
+        },
+      });
+
+    return { success: true };
+  } catch (error: unknown) {
+    if (
+      error &&
+      typeof error === 'object' &&
+      'code' in error &&
+      (error as { code: string }).code === '23505'
+    ) {
+      return { success: false, error: 'Failed to update exchange rate' };
+    }
+    throw error;
+  }
+}
+
+export async function getExchangeRate(from: string, to: string) {
+  const result = await db
+    .select()
+    .from(exchangeRates)
+    .where(
+      eq(exchangeRates.fromCurrency, from.toUpperCase()),
+    )
+    .execute();
+
+  return result[0] || null;
+}
+
+export async function getAllExchangeRates() {
+  return db.select().from(exchangeRates).execute();
+}

src/db/schema.ts

@@ -1,4 +1,4 @@
-import { pgTable, uuid, varchar, timestamp, pgEnum, numeric } from "drizzle-orm/pg-core";
+import { pgTable, uuid, varchar, timestamp, pgEnum, numeric, uniqueIndex } from "drizzle-orm/pg-core";
 
 export const users = pgTable("users", {
   id: uuid("id").primaryKey().$defaultFn(() => crypto.randomUUID()),
@@ -51,3 +51,14 @@ export const transactions = pgTable("transactions", {
   createdAt: timestamp("created_at", { withTimezone: true, mode: "date" })
     .defaultNow(),
 });
+
+export const exchangeRates = pgTable("exchange_rates", {
+  id: uuid("id").primaryKey().$defaultFn(() => crypto.randomUUID()),
+  fromCurrency: varchar("from_currency", { length: 10 }).notNull(),
+  toCurrency: varchar("to_currency", { length: 10 }).notNull(),
+  rate: numeric("rate", { precision: 20, scale: 8 }).notNull(),
+  updatedAt: timestamp("updated_at", { withTimezone: true, mode: "date" })
+    .defaultNow(),
+}, (table) => [
+  uniqueIndex("currency_pair_idx").on(table.fromCurrency, table.toCurrency),
+]);