Oracle intercepts special characters

Oracle Character interception

1.substr(varchar2,start_index,sub_length)

####　 explain ：

1. varchar2 : String to process
2. start_index : Intercept starting position
3. sub_length : Interception length

２.instr(varchar2,char,index,n)

explain ：

1. varchar2 : String to process
2. char : Characters to search
3. index : char Character No index position ,index<0, The sign starts on the right

３． Intercept the first part of a special string

select substr('Ajjjjjsss-36kk699-KL3369',0,(instr('Ajjjjjsss-36kk699-KL3369', '-',1, 1)-1)) from dual;

４． Intercept the second half of the string

select substr('AFGLasa-22589assa-KL33dssdd339',instr('AFGLasa-22589assa-KL33dssdd339', '-',2, 2) + 1,length('AFGLasa-22589assa-KL33dssdd339')) from dual;

５． Intercept the middle part of the string

select substr('kjjshgdhbdf-236688sss-sssasdsd89555',instr('kjjshgdhbdf-236688sss-sssasdsd89555', '-',-1, 2) + 1,
instr('kjjshgdhbdf-236688sss-sssasdsd89555', '-', -1, 1) -(instr('kjjshgdhbdf-236688sss-sssasdsd89555', '-', -1, 2) + 1)) from dual;