(feat) balance

migrations/20251107163729_add_balances_table.sql.sql

@@ -0,0 +1,15 @@
+-- migrations/XXXXXX_add_balances_table.sql
+
+CREATE TABLE IF NOT EXISTS balances (
+    id SERIAL PRIMARY KEY,
+    account_id VARCHAR(50) NOT NULL,
+    balance_type VARCHAR(50) NOT NULL,
+    amount TEXT NOT NULL,
+    currency VARCHAR(3) NOT NULL,
+    date_time TIMESTAMPTZ NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    
+    UNIQUE(account_id, balance_type)
+);
+
+CREATE INDEX IF NOT EXISTS idx_balances_account_id ON balances(account_id);