繁花如伊
Oracle中 其语法为:substr函数的用法,取得字符串中指定起始位置和长度的字符串 ,默认是从起始位置到结束的子串。substr( string, start_position, [ length ] ) substr('目标字符串',开始位置,长度)如:substr('This is a test', 6, 2) would return 'is'substr('This is a test', 6) would return 'is a test'substr('TechOnTheNet', -3, 3) would return 'Net'substr('TechOnTheNet', -6, 3) would return 'The'select substr('Thisisatest', -4, 2) value from dual