如何在數據庫中的隨機字母列表的每個字母后添加逗號

Question

如何在每個字母后添加逗號，如果我的所有記錄都有隨機字母？

我有：

1. AHGJTOSIYGJ 
2. OTPDBSKGY 
3. HFRYEC 
4. OPFKWIFS 
// etc 

我需要的：

1. A, H, G, J, T, O, S, I, Y, G, J, 
2. O, T, P, D, B, S, K, G, Y, 
3. H, F, R, Y, E, C, 
4. O, P, F, K, W, I, F, S, 
// etc 

Answer 1

這些操作應該通過應用程序級而不是數據庫來完成。但是，您真的想從數據庫級別執行此操作，您可以使用用戶定義的函數輕鬆完成此操作。下面是一個函數來做到這一點

delimiter // 

create function myFunction(myString varchar(255)) 
returns varchar(255) 
begin 
declare strLen int ; 
declare lookupChar char(1); 
declare finalString varchar(255); 
declare x int; 

set strLen = length(myString); 
set x = 1 ; 
set finalString = ''; 
while x <= strLen do 
    set lookupChar = substring(myString,x,1); 
    if finalString = '' then 
    set finalString = lookupChar; 
    else 
    set finalString = concat(finalString,',',lookupChar); 
    end if; 
    set x = x+1; 
end while; 
return finalString; 
end// 

delimiter; 

讓我們在MySQL

mysql> create table mytable (id int, value varchar(100)); 
Query OK, 0 rows affected (0.19 sec) 

mysql> insert into mytable values (1,'AHGJTOSIYGJ'),(2,'OTPDBSKGY'),(3,'HFRYEC'),(4,'OPFKWIFS'); 
Query OK, 4 rows affected (0.02 sec) 

mysql> select * from mytable ; 
+------+-------------+ 
| id | value  | 
+------+-------------+ 
| 1 | AHGJTOSIYGJ | 
| 2 | OTPDBSKGY | 
| 3 | HFRYEC  | 
| 4 | OPFKWIFS | 
+------+-------------+ 
4 rows in set (0.00 sec) 

運行此現在，讓我們創建函數

mysql> delimiter // 
mysql> create function myFunction(myString varchar(255)) 
    -> returns varchar(255) 
    -> begin 
    -> declare strLen int ; 
    -> declare lookupChar char(1); 
    -> declare finalString varchar(255); 
    -> declare x int; 
    -> 
    -> set strLen = length(myString); 
    -> set x = 1 ; 
    -> set finalString = ''; 
    -> while x <= strLen do 
    -> set lookupChar = substring(myString,x,1); 
    -> if finalString = '' then 
    ->  set finalString = lookupChar; 
    -> else 
    ->  set finalString = concat(finalString,',',lookupChar); 
    -> end if; 
    -> set x = x+1; 
    -> end while; 
    -> return finalString; 
    -> end// 
Query OK, 0 rows affected (0.00 sec) 

mysql> delimiter ; 

到目前爲止好，現在讓我們選擇使用的值功能

mysql> select id,myFunction(value) as value from mytable ; 
+------+-----------------------+ 
| id | value     | 
+------+-----------------------+ 
| 1 | A,H,G,J,T,O,S,I,Y,G,J | 
| 2 | O,T,P,D,B,S,K,G,Y  | 
| 3 | H,F,R,Y,E,C   | 
| 4 | O,P,F,K,W,I,F,S  | 
+------+-----------------------+ 

Y ou可以爲整個表執行此操作，並且如果需要，還可以輕鬆完成更新。

Answer 2

我們需要序列號的工作表，從1到最大長度的輸入字符串：

create table seqnum(X int not null, primary key(X)); 
insert into seqnum values(1),(2),(3),(4); 
insert into seqnum select X+4 from seqnum; 
insert into seqnum select X+8 from seqnum; 
insert into seqnum select X+16 from seqnum; 
insert into seqnum select X+32 from seqnum; 

測試表E：

create table test6(id int, lett varchar(100)); 
insert into test6 values(1,'AHGJTOSIYGJ'),(2,'OTPDBSKGY'),(3,'HFRYEC'),(4,'OPFKWIFS'); 

查詢選擇上表TEST6改變字母：

select id, lett, group_concat(substr(lett,S.X,1) ORDER BY T.id, S.x SEPARATOR ', ') 
    from test6 T, seqnum S 
where S.X<=length(T.lett) 
group by id 

結果：

1 | AHGJTOSIYGJ | A, H, G, J, T, O, S, I, Y, G, J 
2 | OTPDBSKGY | O, T, P, D, B, S, K, G, Y 
3 | HFRYEC  | H, F, R, Y, E, C 
4 | OPFKWIFS | O, P, F, K, W, I, F, S 

對於現有的表使用查詢的更新值：

update test6 A 
    join (
     select id, group_concat(substr(lett,S.X,1) ORDER BY T.id, S.x SEPARATOR ', ') new 
      from test6 T, seqnum S 
     where S.X>0 and S.X<=length(T.lett) 
     group by id 
     ) B ON A.id=B.id 
    set A.lett=B.new 

Test on sqlfiddle.com