DELIMITER $$
USE `bzmtestenv`$$ -- localDB
DROP FUNCTION IF EXISTS `func_instr_oracle`$$
CREATE DEFINER=`root`@`localhost` FUNCTION `func_instr_oracle`(
f_str VARCHAR(1000), -- Parameter 1
f_substr VARCHAR(100), -- Parameter 2
f_str_pos INT, -- Postion
f_count INT UNSIGNED -- Times
) RETURNS INT(10) UNSIGNED
BEGIN
-- Created by ytt. Simulating Oracle instr function.
-- Date 2015/12/5.
DECLARE i INT DEFAULT 0; -- Postion iterator
DECLARE j INT DEFAULT 0; -- Times compare.
DECLARE v_substr_len INT UNSIGNED DEFAULT 0; -- Length for Parameter 1.
DECLARE v_str_len INT UNSIGNED DEFAULT 0; -- Length for Parameter 2.
SET v_str_len = LENGTH(f_str);
SET v_substr_len = LENGTH(f_substr);
-- Unsigned.
IF f_str_pos > 0 THEN
SET i = f_str_pos;
SET j = 0;
WHILE i <= v_str_len
DO
IF INSTR(LEFT(SUBSTR(f_str,i),v_substr_len),f_substr) > 0 THEN
SET j = j + 1;
IF j = f_count THEN
RETURN i;
END IF;
END IF;
SET i = i + 1;
END WHILE;
-- Signed.
ELSEIF f_str_pos <0 THEN
SET i = v_str_len + f_str_pos+1;
SET j = 0;
WHILE i <= v_str_len AND i > 0
DO
IF INSTR(RIGHT(SUBSTR(f_str,1,i),v_substr_len),f_substr) > 0 THEN
SET j = j + 1;
IF j = f_count THEN
RETURN i - v_substr_len + 1;
END IF;
END IF;
SET i = i - 1;
END WHILE;
-- Equal to 0.
ELSE
RETURN 0;
END IF;
RETURN 0;
END$$
DELIMITER ;
【Mysql】自定义函数:实现oracle instr() 函数功能
最新推荐文章于 2021-03-24 16:10:47 发布
