什么是正确的数字模式

Question

我正在使用 like 运算符寻找正确的模式。

我的代码：

DECLARE @exp1 varchar(100) = '<<PointBalance , 8>>'
DECLARE @exp2 varchar(100) = '<<PointBalance , 985>>'    
IF (TRIM(REPLACE(@exp1, ' ', '')) LIKE '<<PointBalance,[0-9]>>')
    PRINT 'Matched'

正如预期的那样，if 语句不会为 exp2 打印 'Matched'。

位数不同。我需要一个验证 nDigit 数字的模式。

Answer 1

例如，我想使用 substring() 和 patindex() 函数来读取数值并比较整个字符串

DECLARE @exp1 varchar(100) = '<<PointBalance , 811111>>'
DECLARE @exp2 varchar(100) = '<<PointBalance , 489>>'    
IF (trim(REPLACE(@exp2, ' ', '')) like '<<PointBalance,'+substring(@exp2, patindex('%[0-9]%', @exp2), len(replace(@exp2, ' ', '')) - patindex('%[0-9]%', replace(@exp2, ' ', ''))-1)+'>>')
PRINT 'Matched'

Answer 2

Like 模式无法检查可变长度的数字字符串，但它可以检查任何不是数字的字符的子字符串：

-- Sample data.
declare @Samples as Table ( Sample VarChar(32) );
insert into @Samples ( Sample ) values
  ( '<<PointBalance , 1>>' ), ( '<<PointBalance , 12>>' ), ( '<<PointBalance , 123>>' ),
  ( '<<PointBalance , 1234>>' ), ( '<<PointBalance , 1 3 5>>' ), ( '<<PointBalance , 1J3>>' );

with
  Step1 as (
    select Sample,
      -- Extract the substring starting after the comma and trim leading whitespace.
      LTrim( Substring( Sample, CharIndex( ',', Sample ) + 1, 32 ) ) as AfterComma
      from @Samples ),
  Step2 as (
    select Sample, AfterComma,
      -- Extract the substring prior to the first   '>'   and trim trailing whitespace.
      RTrim( Substring( AfterComma, 1, CharIndex( '>', AfterComma ) - 1 ) ) as TargetString
      from Step1 )
select *,
  -- Check the remaining string for any characters that are not digits.
  case when TargetString like '%[^0-9]%' then 0 else 1 end as Numeric
  from Step2;

什么是正确的数字模式

What is correct like pattern for number

sql

sql-server

tsql

sql-like

sql-server-2017