chore: initial commit

internal/db/schema/categories.sql

@@ -0,0 +1,19 @@
+-- 分类表
+CREATE TABLE categories
+(
+    id         INTEGER PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
+    name       TEXT        NOT NULL,
+    code       TEXT UNIQUE NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ
+);
+
+CREATE TRIGGER update_categories_updated_at
+    BEFORE UPDATE
+    ON categories
+    FOR EACH ROW
+EXECUTE FUNCTION update_updated_at_column();
+
+COMMENT ON COLUMN categories.id IS '分类ID';
+COMMENT ON COLUMN categories.name IS '分类名称';
+COMMENT ON COLUMN categories.code IS '分类编码';