SQL Server判断是否满足日期格式（YYYYMMDD）以及中文等判断，格式化为YYYY-MM-DD

SQL Server判断是否满足日期格式（YYYYMMDD）以及中文等判断：

在做sql数据的正确性审核中，需要判断数据是否满足日期格式，网上找不到相关的资料，于是自己花了半天写了一个简单的函数

具体思路：

1.判断字符串是否8位

2.如果是8位，通过datalength判断是否8位，如果不是8位，说明字符串中存在汉字或者不可见字符

3.通过Ascii码对8位中的每一位字符进行判断，目的是判断是否数字（按照AsciI码可以避免不可见字符）

4.如果符合上述3中条件，说明字符是8位的数字，判断是否正常日期

 1 ALTER FUNCTION [dbo].[isDataYYYYMMDD]( @Number nvarchar(50))
 2 RETURNS int
 3 AS 
 4 begin
 5 　　if LEN(ltrim(rtrim(@Number)))<>8 or CHARINDEX('.',@Number)>0 or CHARINDEX('#',@Number)>0 or CHARINDEX('*',@Number)>0 or CHARINDEX('-',@Number)>0 or 　　　　CHARINDEX('',@Number)>0 or CHARINDEX('/',@Number)>0
 6 　　　　begin
 7 　　　　　　return 1
 8 　　　　end
 9 　　else if datalength(ltrim(rtrim(@Number)))<> 8
10 　　　　if ascii(left(@Number,1))> 57 or ascii(left(@Number,1))<48 
11 　　　　　　or ascii(right(left(@Number,2),1))> 57 or ascii(right(left(@Number,2),1))<48
12 　　　　　　or ascii(right(left(@Number,3),1))> 57 or ascii(right(left(@Number,3),1))<48
13 　　　　　　or ascii(right(left(@Number,4),1))> 57 or ascii(right(left(@Number,4),1))<48
14 　　　　　　or ascii(right(left(@Number,5),1))> 57 or ascii(right(left(@Number,5),1))<48
15 　　　　　　or ascii(right(left(@Number,6),1))> 57 or ascii(right(left(@Number,6),1))<48
16 　　　　　　or ascii(right(left(@Number,7),1))> 57 or ascii(right(left(@Number,7),1))<48
17 　　　　　　or ascii(right(left(@Number,8),1))> 57 or ascii(right(left(@Number,8),1))<48
18 　　　　　　begin
19 　　　　　　　　return 1
20 　　　　　　end
21 　　　　else 
22 　　　　　　begin
23 　　　　　　　　return 0
24 　　　　　　end
25 　　else
26 　　　　begin
27 　　　　　　if DATENAME ( year ,@Number)>2017 
28 　　　　　　　　begin
29 　　　　　　　　　　return 1
30 　　　　　　　　end
31 　　　　　　else if DATENAME ( month ,@Number)>12 or DATENAME ( month ,@Number)<1
32 　　　　　　　　begin
33 　　　　　　　　　　return 1
34 　　　　　　　　end 
35 　　　　　　else if DATENAME ( DAY ,@Number)>31 or DATENAME ( DAY ,@Number)<1 
36 　　　　　　　　begin
37 　　　　　　　　　　return 1
38 　　　　　　　　end 
39 　　　　end
40 　　return 0
41 end

2.格式化为YYYY-MM-DD

去掉0:20170909:2017-9-9

  1 ALTER FUNCTION [dbo].[formatTime]( @Number nvarchar(500))
  2 RETURNS nvarchar(500)
  3 --返回-1，表示字符串存在问题
  4 --else返回其计算结果
  5 AS
  6 begin
  7 --判断非法字符
  8 if PATINDEX('%[^0123456789]%', @Number)>0
  9 begin
 10 return @Number
 11 end
 12 --如果长度小于4位，eg：2004，200，就直接返回
 13 else if len(@Number)<=4
 14 begin
 15 return @Number
 16 end
 17 --如果长度为5位，eg：20045，返回2004-5
 18 else if len(@Number)=5
 19 begin
 20 if right(@Number,1)='0'
 21 begin
 22 return left(@Number,4)
 23 end
 24 else
 25 begin
 26 return left(@Number,4)+'-'+right(@Number,1)
 27 end
 28 end
 29 --如果长度为6位
 30 else if len(@Number)=6
 31 begin
 32 if right(@Number,2)<='12'
 33 begin
 34 if left(right(@Number,2),1)='0'
 35 begin
 36 return left(@Number,4)+'-'+right(@Number,1) 
 37 end
 38 else 
 39 begin
 40 return left(@Number,4)+'-'+right(@Number,2)
 41 end
 42 end
 43 else 
 44 begin
 45 if right(@Number,1)='0'
 46 begin
 47 return left(@Number,4)+'-'+left(right(@Number,2),1)
 48 end
 49 else
 50 begin
 51 return left(@Number,4)+'-'+left(right(@Number,2),1)+'-'+right(@Number,1)
 52 end
 53 end
 54 end
 55 --如果长度为7位
 56 else if len(@Number)=7
 57 begin
 58 --第5,6位组合起来，小于12 eg:2015111 2015-11-1
 59 if left(right(@Number,3),2)<='12'
 60 begin
 61 if left(right(@Number,3),1)='0' and right(@Number,1)<>'0'
 62 begin
 63 return left(@Number,4)+'-'+left(right(@Number,2),1)+'-'+right(@Number,1)
 64 end
 65 else if left(right(@Number,3),1)='0' and right(@Number,1)='0'
 66 begin
 67 return left(@Number,4)+'-'+left(right(@Number,2),1)
 68 end
 69 else if left(right(@Number,3),1)<>'0' and right(@Number,1)='0'
 70 begin
 71 return left(@Number,4)+'-'+left(right(@Number,3),2)
 72 end
 73 else 
 74 begin
 75 return left(@Number,4)+'-'+left(right(@Number,3),2)+'-'+right(@Number,1)
 76 end
 77 end
 78 --第5,6位组合起来大于12，且第6,7位小于31， eg:2015211 2015-2-11
 79 else if left(right(@Number,3),2)>'12' and right(@Number,2)<='31'
 80 begin
 81 if right(@Number,2)='00'
 82 begin
 83 return left(@Number,4)+'-'+left(right(@Number,3),1)
 84 end
 85 else if left(right(@Number,2),1)='0'
 86 begin
 87 return left(@Number,4)+'-'+left(right(@Number,3),1)+'-'+right(@Number,1)
 88 end
 89 end
 90 --第5,6位组合起来大于12，且第6,7位大于31， eg:2015235 不合理
 91 else 
 92 return @Number
 93 end
 94 --如果长度为8位
 95 else if len(@Number)=8
 96 begin
 97 if left(right(@Number,4),2)<='12' and right(@Number,2)<='31'
 98 begin
 99 if left(right(@Number,4),2)='00' or right(@Number,2)='00'
100 begin
101 return @Number
102 end
103 else if left(right(@Number,4),1)='0' and left(right(@Number,2),1)='0'
104 begin
105 return left(@Number,4)+'-'+left(right(@Number,3),1)+'-'+right(@Number,1)
106 end
107 else if left(right(@Number,4),1)='0' and left(right(@Number,2),1)<>'0'
108 begin
109 return left(@Number,4)+'-'+left(right(@Number,3),1)+'-'+right(@Number,2)
110 end
111 else if left(right(@Number,4),1)<>'0' and left(right(@Number,2),1)='0'
112 begin
113 return left(@Number,4)+'-'+left(right(@Number,4),2)+'-'+right(@Number,1)
114 end
115 else
116 return left(@Number,4)+'-'+left(right(@Number,4),2)+'-'+right(@Number,2)
117 end
118 else --不合法
119 begin
120 return @Number
121 end
122 end
123 else --不合法
124 begin
125 return @Number
126 end
127 return '0'
128 end

不去0:20170909:2017-09-09

 1 ALTER FUNCTION [dbo].[formatTime1]( @Number nvarchar(500))
 2 RETURNS nvarchar(500)
 3 --返回-1，表示字符串存在问题
 4 --else返回其计算结果
 5 AS
 6 begin
 7 --判断非法字符
 8 if PATINDEX('%[^0123456789]%', @Number)>0
 9 begin
10 return @Number
11 end
12 --如果长度小于4位，eg：2004，200，就直接返回
13 else if len(@Number)<=4
14 begin
15 return @Number
16 end
17 --如果长度为5位，eg：20045，返回2004-5
18 else if len(@Number)=5
19 begin
20 return left(@Number,4)+'-'+right(@Number,1)
21 end
22 --如果长度为6位
23 else if len(@Number)=6
24 begin
25 if right(@Number,2)<='12'
26 begin
27 return left(@Number,4)+'-'+right(@Number,2)
28 end
29 else 
30 begin
31 return left(@Number,4)+'-'+left(right(@Number,2),1)+'-'+right(@Number,1)
32 end
33 end
34 --如果长度为7位
35 else if len(@Number)=7
36 begin
37 --第5,6位组合起来，小于12 eg:2015111 2015-11-1
38 if left(right(@Number,3),2)<='12'
39 begin
40 return left(@Number,4)+'-'+left(right(@Number,3),2)+'-'+right(@Number,1)
41 end
42 --第5,6位组合起来大于12，且第6,7位小于31， eg:2015211 2015-2-11
43 else if left(right(@Number,3),2)>'12' and left(@Number,2)<='31'
44 begin
45 return left(@Number,4)+'-'+left(right(@Number,3),1)+'-'+right(@Number,2)
46 end
47 --第5,6位组合起来大于12，且第6,7位大于31， eg:2015235 不合理
48 else 
49 return @Number
50 end
51 --如果长度为8位
52 else if len(@Number)=8
53 begin
54 if left(right(@Number,4),2)<='12' and right(@Number,2)<='31'
55 begin
56 return left(@Number,4)+'-'+left(right(@Number,4),2)+'-'+right(@Number,2)
57 end
58 else --不合法
59 begin
60 return @Number
61 end
62 end
63 else --不合法
64 begin
65 return @Number
66 end
67 return '0'
68 end