建表语句：

```sql
CREATE TABLE `example_table` (
    `id` BIGINT NOT NULL COMMENT 'ID',
    `str_field` VARCHAR(32) NOT NULL COMMENT '字符串`,
    `int_field` INT DEFAULT NULL COMMENT '整数`,
    `long_field` BIGINT DEFAULT NULL COMMENT '长整数`,
    `decimal_field` DECIMAL(14, 2) DEFAULT NULL COMMENT '高精度浮点数`,
    `date_field` DATE NOT NULL COMMENT '日期类型`,
    `time_field` DATETIME NOT NULL COMMENT '日期类型`,
    `state` VARCHAR(32) NOT NULL COMMENT '状态：only_read、read_write',
    `json_field` JSON DATETIME NULL COMMENT 'JSON类型'
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='示例表';
```