取一对括号中间内容
SELECT SUBSTR(column_name, 
              INSTR(column_name, '(') + 1, 
              INSTR(column_name, ')') - INSTR(column_name, '(') - 1) 
AS content_between_parentheses
FROM table_name;
        某字符值中abc之后def之前部分
SELECT
  SUBSTR(your_column, 
    INSTR(your_column, 'abc') + LENGTH('abc'), 
    INSTR(your_column, 'def') - INSTR(your_column, 'abc') - LENGTH('abc')
  ) AS extracted_string
FROM
  your_table
WHERE
  your_column LIKE '%abc%def%';
        将形似'1E+9'某字符串转为数字
select to_number('1E+9') from dual