SQL Server获取下一个编码字符串的实现方案分割和进位

  1 IF OBJECT_ID(N‘dbo.ufn_GetNextCodeChars‘, ‘FN‘) IS NOT NULL
  2 BEGIN
  3     DROP FUNCTION dbo.ufn_GetNextCodeChars;
  4 END
  5 GO
  6  
  7 --==================================
  8 -- 功能: 获取下一个编码字符串
  9 -- 说明: 具体实现阐述 
 10 -- 作者: XXX
 11 -- 创建: yyyy-MM-dd
 12 -- 修改: yyyy-MM-dd XXX 修改内容描述
 13 --==================================
 14 CREATE FUNCTION dbo.ufn_GetNextCodeChars
 15 (
 16     @chvCodeChars VARCHAR(19)            -- 编码字符串,首字符必须以字母A-Z任意一个开始。
 17 ) RETURNS VARCHAR(19)
 18     --$Encode$--
 19 AS
 20 BEGIN;
 21     SET @chvCodeChars = ISNULL(@chvCodeChars, ‘‘);
 22     SET @chvCodeChars = UPPER(@chvCodeChars);
 23  
 24     -- 下一个编码字符串变量
 25     DECLARE @chvNextCodeChars AS VARCHAR(19);
 26     SET @chvNextCodeChars = ‘‘;
 27  
 28     -- 编码字符使用的字符字符串变量
 29     DECLARE @chCharStr AS CHAR(36);
 30     SET @chCharStr = ‘0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ‘;
 31  
 32     DECLARE 
 33         @tintLength AS TINYINT,                
 34         @tintFistNumPos AS TINYINT;
 35     SELECT
 36         @tintLength = LEN(@chvCodeChars),    -- 编码字符串长度变量    
 37         @tintFistNumPos = 2;                -- 首个数字字符所在位置的变量，默认第二个字符是数字字符
 38  
 39     DECLARE
 40         @chvLetterChars AS VARCHAR(19),     -- 字母字符串
 41         @chvNumChars AS VARCHAR(19);        -- 数字字符串
 42     SELECT
 43         @chvLetterChars = ‘‘,
 44         @chvNumChars = ‘‘;
 45  
 46     -- 字符ASCII值变量    
 47     DECLARE @tintASCIIValue AS TINYINT;
 48     SET @tintASCIIValue = 0;
 49  
 50     -- 编码字符串长度的逻辑检查
 51     IF @tintLength NOT BETWEEN 1 AND 19
 52     BEGIN
 53         RETURN @chvNextCodeChars;
 54     END
 55  
 56     -- 首字符是否字母字符的逻辑检查
 57     SET @tintASCIIValue = ASCII(SUBSTRING(@chvCodeChars, 1, 1));
 58     IF @tintASCIIValue NOT BETWEEN ASCII(‘A‘) AND ASCII(‘Z‘)
 59     BEGIN
 60         RETURN @chvNextCodeChars;
 61     END
 62  
 63     -- 所有字符全部为‘Z‘的逻辑检查
 64     IF @chvCodeChars = REPLICATE(‘Z‘, @tintLength)
 65     BEGIN
 66         RETURN @chvNextCodeChars;
 67     END
 68  
 69     -- 找到到首个数字字符的位置(其所在编码字符串中的位置)
 70     WHILE @tintFistNumPos <= @tintLength
 71     BEGIN
 72         SET @tintASCIIValue = ASCII(SUBSTRING(@chvCodeChars, @tintFistNumPos, 1));
 73         IF @tintASCIIValue BETWEEN ASCII(‘0‘) AND ASCII(‘9‘)
 74         BEGIN
 75             BREAK;
 76         END
 77  
 78         SET @tintFistNumPos = @tintFistNumPos + 1;
 79     END
 80  
 81     -- 分割编码字符串分别带到字母字符串和数字字符串
 82     SET @chvLetterChars = SUBSTRING(@chvCodeChars, 1, @tintFistNumPos - 1);
 83     -- 只有找到数字字时才分割获得数字字符串
 84     IF @tintFistNumPos <= @tintLength
 85     BEGIN
 86         SET @chvNumChars = SUBSTRING(@chvCodeChars, @tintFistNumPos, @tintLength - @tintFistNumPos + 1);
 87     END
 88  
 89     -- 字母字符串长度和字母字符串最后一个字母
 90     DECLARE
 91         @tintLetterLength AS TINYINT,
 92         @chLastLetter AS CHAR(1);
 93     SELECT
 94         @tintLetterLength = LEN(@chvLetterChars),
 95         @chLastLetter = SUBSTRING(@chvLetterChars, @tintLetterLength, 1);
 96  
 97     IF LEN(@chvNumChars) = 0        /*最后一位不为Z或是数字字符时的逻辑处理*/
 98     BEGIN
 99         SET @chvLetterChars = SUBSTRING(@chvLetterChars, 1, @tintLetterLength - 1)
100                               + SUBSTRING(@chCharStr, CHARINDEX(@chLastLetter, @chCharStr, 1) + 1, 1);
101     END
102     ELSE                    /*数字字符超过1位(最多18位)时逻辑处理*/
103     BEGIN
104         -- 声明一个特殊的整数变量，开始为“1”后边紧跟数字字符串，在转为整数进行加法运算，如果该结果首字符从1变成了2，则表示前面相邻的字母字符需要递进增加；否则只是数字字符串进行递进增加。
105         DECLARE @bintNumPlusOne AS BIGINT;
106         SET @bintNumPlusOne = CAST(‘1‘ + + @chvNumChars AS BIGINT) + 1;
107  
108         IF SUBSTRING(CAST(@bintNumPlusOne AS VARCHAR(19)), 1, 1) = ‘2‘ /*数字字符串全部为9*/
109         BEGIN 
110             IF @chLastLetter = ‘Z‘ /*如果数字字符串相邻前面字母为‘Z‘,则第一个数字变为‘A‘，其余的数字字符串全部变为0*/
111             BEGIN
112                 SET @chvNumChars = ‘A‘ + REPLICATE(‘0‘, LEN(@chvNumChars) - 1);
113             END
114             ELSE                            /*如果数字字符串相邻前面字母不为‘Z‘,则这个字母递进增加，数字字符串全部变为0*/
115             BEGIN
116                 SET @chvLetterChars = SUBSTRING(@chvLetterChars, 1, @tintLetterLength - 1)
117                                         + SUBSTRING(@chCharStr, CHARINDEX(@chLastLetter, @chCharStr, 1) + 1, 1);
118  
119                 SET @chvNumChars = REPLICATE(‘0‘, LEN(CAST(@bintNumPlusOne AS VARCHAR(19))) - 1);
120             END       
121         END
122         ELSE                                                            /*数字字符串第一个数字字符不为9，其余的数字字符可全部为9*/
123         BEGIN
124             SET @chvNumChars = STUFF(CAST(@bintNumPlusOne AS VARCHAR(19)), 1, 1, ‘‘);
125         END  
126     END
127  
128     -- 将字母字符串和数字字符串一起组装成下一个编码字符串
129     SET @chvNextCodeChars = @chvLetterChars + @chvNumChars;
130  
131     RETURN @chvNextCodeChars;
132 END
133 GO

 1 DECLARE @chvCodeChars AS VARCHAR(19);
 2  
 3 SET @chvCodeChars = ‘ZZZZZZZZZZZZZZZZZ99‘ 
 4 SELECT @chvCodeChars AS [当前编码字符串], dbo.ufn_GetNextCodeChars(@chvCodeChars) AS [相邻前面字母为Z且字母进位];
 5  
 6 SET @chvCodeChars = ‘AAAA99‘;
 7 SELECT @chvCodeChars AS [当前编码字符串], dbo.ufn_GetNextCodeChars(@chvCodeChars) AS [相邻前面字母不为Z且字母进位];
 8  
 9 SET @chvCodeChars = ‘ZZZZZZZZZZZZZZZZA99‘;
10 SELECT @chvCodeChars AS [当前编码字符串], dbo.ufn_GetNextCodeChars(@chvCodeChars) AS [相邻前面字母不为Z且字母进位];
11  
12 SET @chvCodeChars = ‘ZZZZZZZZZZZZZZZZB00‘;
13 SELECT @chvCodeChars AS [当前编码字符串], dbo.ufn_GetNextCodeChars(@chvCodeChars) AS [数字进位];
14  
15 SET @chvCodeChars = ‘ZZZZZZZZZZZZZZZZZA‘;
16 SELECT @chvCodeChars AS [当前编码字符串], dbo.ufn_GetNextCodeChars(@chvCodeChars) AS [全为字母且字母进位];
17 GO