Sybase数据库技术，数据库恢复专家

Sybase ASE自版本15.0.2开始增加判断字符串是否为日期类型的函数：isdate，以及判断字符串是否为数字类型的函数：isnumeric

函数：isdate

Syntax

isdate(character_expression)

Parameters

character_expression

    is a character-type variable, constant expression, or column name.

Usage

Returns 1 if the expression is a valid datetime value; returns 0 if it is not. Returns 0 for NULL input.

例子：

1> select isdate('12/21/2005')
2> go

 -----------
           1

(1 row affected)
1> select isdate('12212005')
2> go

 -----------
           0

(1 row affected)
1> select isdate('20050228')
2> go

 -----------
           1

(1 row affected)
1> select isdate('20050229')
2> go

 -----------
           0

(1 row affected)
 

函数：isnumeric

Syntax

isnumeric (character_expression)

Parameters

character_expression

           is a character-type variable, constant expression, or a column name.

Usage

    *  Returns 1 if the input expression is a valid integer, floating point number, money or decimal type; returns 0 if it does not or if the input is a NULL value. A return value of 1 guarantees that you can convert the expression to one of these numeric types.
    *  You can include currency symbols as part of the input.
 

例子：

1> select isnumeric("$100.12345")
2> go

 -----------
           1

(1 row affected)
1> select isnumeric("-0.001")
2> go

 -----------
           1

(1 row affected)
1> select isnumeric("￥123")
2> go

 -----------
           0

(1 row affected)
1> select isnumeric("123,456.001")
2> go

 -----------
           1

(1 row affected)