try_to_number
try_to_number 介绍
try_to_number(expr, fmt) - 根据字符串格式fmt将字符串expr转换为数字。如果字符串expr与预期格式不匹配，则返回NULL。该格式遵循与to_number函数相同的语义。
Examples:
> SELECT try_to_number('454', '999');
454
> SELECT try_to_number('454.00', '000.00');
454.00
> SELECT try_to_number('12,454', '99,999');
12454
> SELECT try_to_number('$78.12', '$99.99');
78.12
> SELECT try_to_number('12,454.8-', '99,999.9S');
-12454.8Since: 3.3.0