MySQL JSON查询与索引详解

CREATE TABLE `t_config` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
  `extras` json DEFAULT NULL COMMENT '扩展列json字段',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='配置表';

INSERT INTO `t_config` (`id`, `extras`) VALUES (1, '{\"color\": \"red\", \"phone\": [\"157\", \"153\"]}');
INSERT INTO `t_config` (`id`, `extras`) VALUES (2, '{\"color\": \"green\", \"phone\": [\"157\", \"154\"]}');

SELECT * FROM `t_config` WHERE extras->'$.color' = 'red';
或
SELECT * FROM `t_config` WHERE json_contains(extras->'$.color','"red"');

ALTER TABLE `t_config`
ADD COLUMN `v_color` VARCHAR(32) GENERATED ALWAYS AS
(JSON_UNQUOTE(JSON_EXTRACT(`extras`, _utf8mb4'$.color'))) VIRTUAL NULL;
CREATE INDEX idx_v_color on t_config(v_color);

EXPLAIN SELECT * FROM `t_config` WHERE v_color = 'red';

SELECT * FROM `t_config` WHERE json_contains(extras->'$.color','"red"');
 或者
SELECT * FROM `t_config` WHERE extras->'$.color' = 'red';  

EXPLAIN SELECT * FROM `t_config` WHERE json_contains(extras->'$.color','"red"');

alter table t_config add index json_color( (cast(extras->'$.color' as char(32) array)));

alter table t_config add index phone( (cast(extras->'$.phone' as unsigned array)) );

 -- 查询phone字段
 SELECT * FROM `t_config` WHERE json_contains(extras->'$.phone' , '157');
-- 查询phone字段, 参数数组
 SELECT * FROM `t_config` WHERE json_contains(extras->'$.phone' , CAST('[157,153]' AS JSON));