今天有人問了個關於Oracle字符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着解決下,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,下面貼出問題和腳本:
問題:sql中一個字段值爲:1788987565327、768374872394903、21437238740213483874629、23412341234252345。其中頓號間隔的每一組數字位數和尾數不定,現在要使前面這個字段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
腳本:
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:
原字符串: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