sevens

If there is a string "aa, bb, cc, dd", how to realize the separation according to "," and take out the strings "aa", "bb", "cc", "dd"

我是杀人狂

substring ('aa, bb, cc, dd', 1,2)
substring ('aa, bb, cc, dd', 4,2)
substring ('aa, bb, cc, dd', 7,2)
substring ('aa, bb, cc, dd', 10,2)

sevens

Not so, the number of characters in it is not necessarily 2
The string may be ('aa', 'dfsd', 'sdfaw', 'dsfdsfadsf')

sevens

It ’s best to find out where each "," is

idpublic

where the instr function finds

Cyclic processing

idpublic

DECLARE
j INT;
aa VARCHAR2 (300);
bb VARCHAR2 (10);
cc VARCHAR2 (20);
BEGIN
j: = 1;
aa: = 'aa, bb, cc, dd';
bb: = ',';
WHILE j <> 0
LOOP
j: = INSTR (aa, bb);
IF j = 0 THEN
cc: = SUBSTR (aa, j + 1, LENGTH (aa));
ELSE
cc: = SUBSTR (aa, 1, j-1);
aa: = SUBSTR (aa, j + 1, LENGTH (aa));
END IF;
--DBMS_OUTPUT.PUT_LINE (aa);
--DBMS_OUTPUT.PUT_LINE (j);
DBMS_OUTPUT.PUT_LINE (cc);
END LOOP;
END;

idpublic

aa
bb
cc
dd