以下是重构后的SQL代码,保持了原始内容的结构和注释:
```sql
CREATE TABLE `regions` (
`id` int(6) UNSIGNED NOT NULL COMMENT '编号',
`parent_id` int(6) NOT NULL DEFAULT 0 COMMENT '上级编号',
`deep` tinyint(1) NOT NULL DEFAULT 0 COMMENT '层级(0 省 1市 2 区)',
`name` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL DEFAULT '' COMMENT '名称',
`pinyin` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '拼音',
`pinyin_short` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAUL
);
```