当我们不知道sql中的确切格式时，如何为标志列添加检查约束？

Question

这里的第一个字母应该是一个字母，列可以包含任意数量的数据，用“ /”分隔，对于每个我想要的字母，第一个字母之后可以包含3或4个字母。如何动态执行此操作。

我在考虑...首先我可以找到“ /”的位置并将其添加到一个位置，这里我们将获得字母位置，然后可以检查它是字母还是数字字符

Answer 1

您应该接受有关规范化的评论-但是，您应该能够在没有UDF的情况下执行此操作。

CREATE TABLE #T
(
Flag VARCHAR(100) CHECK (
                         /*Only contains alpha, digits and slash*/
                         Flag NOT LIKE '%[^a-zA-Z0-9/]%' COLLATE Latin1_General_100_BIN2 AND 
                         /*Doesn't end in a slash*/
                         Flag NOT LIKE '%/' AND 
                         /*Start of the string and every slash should be followed by an alpha*/
                        '/' + Flag NOT LIKE '%/[^a-zA-Z]%' COLLATE Latin1_General_100_BIN2 AND 
                         /*Should never have a digit immediately followed by an alpha*/
                              Flag NOT LIKE '%[0-9][a-zA-Z]%' COLLATE Latin1_General_100_BIN2 AND 
                         /*Should never have two alpha in a row*/
                              Flag NOT LIKE '%[a-zA-Z][a-zA-Z]%' COLLATE Latin1_General_100_BIN2 AND            
                         /*Should never have 5 digits in a row*/        
                              Flag NOT LIKE '%[0-9][0-9][0-9][0-9][0-9]%' COLLATE Latin1_General_100_BIN2 AND       
                         /*Should not have codes of less than 4 characters*/    
                             '/' + Flag + '/' NOT LIKE '%/_/%' AND          
                             '/' + Flag + '/' NOT LIKE '%/__/%' AND                 
                             '/' + Flag + '/' NOT LIKE '%/___/%'                                                                                    
                        )
);