#json解析函数
DELIMITER $$
DROP FUNCTION IF EXISTS `json_extract_c`$$
CREATE FUNCTION `json_extract_c`(
details TEXT,
required_field VARCHAR (255)
) RETURNS TEXT CHARSET latin1
BEGIN
SET details = SUBSTRING_INDEX(details, "{", -1);
SET details = SUBSTRING_INDEX(details, "}", 1);
RETURN TRIM(
BOTH '"' FROM SUBSTRING_INDEX(
SUBSTRING_INDEX(
SUBSTRING_INDEX(
details,
CONCAT(
'"',
SUBSTRING_INDEX(required_field,'$.', -1),
'":'
),
-1
),
',"',
1
),
':',
-1
)
) ;
END$$
DELIMITER ;
example：
select json_extract_c(json, "$.totalDays"), json from item limit 100;
