Oracle字串截取和拼接應用
今天有人問了個關於Oracle字串截取和拼接的問題,讓我幫他寫出SQL,看了下問題描述還比較清晰就試著解決下,利用午休時間把功能實現了,問題看似不難,但思路一定要清晰,不然就亂了,關鍵大量應用了Oracle的substr 和instr函數。下面貼出問題和指令碼:
問題:sql中一個欄位值為:1788987565327、768374872394903、21437238740213483874629、23412341234252345。其中頓號間隔的每一組數字位元和尾數不定,現在要使前面這個欄位值中頓號前的數字尾數即7、3、9、5都分別加1,變成8、4、0、6輸出成1788987565328、768374872394904、21437238740213483874620、23412341234252346。注意其中第三個數,從9加1後,輸出成0,而不是10
指令碼:
declare
targetstr varchar2(2000);
strlength number;
position number;
maxposition number;
retrunstr varchar2(2000);
tempstr varchar2(2000);
endstr number;
begin
targetstr := '1788987565327、768374872394903、21437238740213483874629、23412341234252345';
maxposition := 0;
select LENGTH(targetstr) into strlength from dual;
for i in 1..strlength loop
select instr(str,'、',1,i) into position from (select targetstr as str from dual);
--dbms_output.PUT_LINE(position);
if position > 0 then
if maxposition = 0 then
select substr(str,0,instr(str,'、',1,1)-1) into retrunstr from (select targetstr as str from dual);
select TO_NUMBER(substr(restr,-1)) into endstr from (select retrunstr as restr from dual);
if endstr = 3 or endstr = 5 or endstr = 7 then
endstr := endstr + 1;
elsif endstr = 9 then
endstr := 0;
end if;
select substr(str,0,instr(str,'、',1,1)-2)||TO_CHAR(endstr) into retrunstr from (select targetstr as str from dual);
elsif maxposition < position then
select substr(str,instr(str,'、',1,i-1)+1,instr(str,'、',1,i)-instr(str,'、',1,i-1)-1) into tempstr from (select targetstr as str from dual);
select TO_NUMBER(substr(restr,-1)) into endstr from (select tempstr as restr from dual);
if endstr = 3 or endstr = 5 or endstr = 7 then
endstr := endstr + 1;
elsif endstr = 9 then
endstr := 0;
end if;
select substr(str,1,length(str)-1) ||TO_CHAR(endstr) into tempstr from (select tempstr as str from dual);
retrunstr := retrunstr || '、'|| tempstr;
end if;
maxposition := position;
else
if maxposition > position then
--特別處理最後一段
tempstr := '';
select substr(str,maxposition-length(str)) into tempstr from (select targetstr as str from dual);
select TO_NUMBER(substr(restr,-1)) into endstr from (select tempstr as restr from dual);
if endstr = 3 or endstr = 5 or endstr = 7 then
endstr := endstr + 1;
elsif endstr = 9 then
endstr := 0;
end if;
select substr(str,1,length(str)-1) ||TO_CHAR(endstr) into tempstr from (select tempstr as str from dual);
retrunstr := retrunstr || '、'|| tempstr;
end if;
exit;
end if;
end loop;
dbms_output.PUT_LINE(retrunstr);
end;
運行結果如下:
原字串:1788987565327、768374872394903、21437238740213483874629、23412341234252345
14:03:38 **** SCRIPT STARTED: 02-Apr-2015 14:03:38 ****
14:03:38 declare
14:03:38 targetstr varchar2(2000);
14:03:38 ...
14:03:39 PL/SQL block executed
1788987565328、768374872394904、21437238740213483874620、23412341234252346
14:03:39 **** SCRIPT ENDED 02-Apr-2015 14:03:39 ****
14:03:39 End Script Execution