A number is judged in SQL Server (the. 3 is automatically recognized as 0.3)

SQL Server detects data that is not digital (two methods)

Detection is not a digital type of data, two methods

1. IsNumeric ( expression )

2. PATINDEX ( '%pattern%' , expression )

1. IsNumeric ( expression )

Returns 1 if it is a numeric type, or 0 if not

But IsNumeric is sometimes unreliable, and if you do not allow expression to contain any letters, you will be judged wrong:

Example: IsNumeric (' 23e4 ') returns 1

IsNumeric (' 23d4 ') returns 1

2. PATINDEX ( '%pattern%' , expression )

The return value is the first position that satisfies the pattern, and if not met, the return value is 0

Determine if a number type

PATINDEX ('%[^0-9]% ', expression)

The return value is 0 , it is a purely numeric type

The notation for supporting decimal and positive numbers is

PATINDEX ('%[^0-9|.| -|+]% ', expression)

A number is judged in SQL Server (the. 3 is automatically recognized as 0.3)