Oracle中获取字符串下标、截取字符串

Oracle中获取字符串下标、截取字符串

获取下标：

SELECT INSTR('AAA-BBB-CCC-DDD', '-', 1, 1) as 字符位置 FROM dual

截取字符串：

SELECT SUBSTR('AAA-BBB-CCC-DDD', 1, 3) as 截取字符串 FROM DUAL

解释：