表的DDL：

CREATE TABLE "AUTH_USER_REGISTRATION" 
   (    "USER_ID" NUMBER(*,0), 
    "USER_NAME" VARCHAR2(200 BYTE), 
    "MAIL" VARCHAR2(400 BYTE), 
    "FULLNAME" VARCHAR2(200 BYTE), 
    "GENDER" VARCHAR2(50 BYTE), 
    "USER_DAY" VARCHAR2(10 BYTE), 
    "USER_MONTH" VARCHAR2(50 BYTE), 
    "USER_YEAR" VARCHAR2(50 BYTE), 
    "CREATED" NUMBER(38,0), 
    "STATUS" VARCHAR2(10 BYTE), 
    "UU_ID" VARCHAR2(100 BYTE), 
    "MOBILE" VARCHAR2(100 BYTE), 
    "CHANGED" NUMBER(38,0)
   );

插入语句：

Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (914981,'srik1977@gmail.com','srikes1977@gmail.com','Birendra Mohan',null,'05','March','1977',1412433302,'1','69945218-cc7f-46f5','9471067',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (916653,'mah@gmail.com','mahe@gmail.com','MAHESH DEOCHAKE','male','18','July','1989',1412439002,'1','4563adc0-345b-4779-a8ee','7709910',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (916665,'hars@hotmail.com','haveri@hotmail.com','Harshal Jhaveri',null,'08','May','1992',1412439002,'1','a10a3f0c-5892-4579-aef6-46a','8568013',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (890991,'gu1952@gmail.com','gunran1952@gmail.com','subramani gunasekaran','male','17','October','1950',1412358602,'1','6b4c7077-8864-4702-','44697999',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (891053,'amini@gmail.com','amihani@gmail.com','AMIR RANJAN DHANI','male','20','August','1992',1412358602,'1','62dd0cb4-c86b-4634-ba6','9432880',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (891055,'pringhc0@gmail.com','pravghc0@gmail.com','Praveen Singh Chouhan','male','10','April','1990',1412358602,'1','037f1079-db85-49d7','04663542',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (892719,'badkt@yahoo.com','bammadkt@yahoo.com','Muhammed Basheer','male','05','July','1994',1412362502,'1','10c07ce7-badf-4204-b2a9','7232903',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (892729,'swaar@gmail.com','swnwar@gmail.com','swapnil papinwar','male','08','September','1986',1412362502,'1','2f8940ef-3136-425','9818122',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (896209,'raj@yahoo.com','rajan@yahoo.com','Rajiv Nayan','male','10','June','1969',1412388301,'1','8008f636-916b-4982-baad-','9810769',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (465,'Jaysparikh','jay@gmail.com','Jay Parikh','male','31','January','1984',1406359580,'1','c04b7129-b04e-4ca5-9199-','9586817',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (476,'sknyer','sknr@gmail.com','Sasidharan Nair','male','26','October','1968',1406359591,'1','69288f05-bfbb-4f5e-9561-71e','530154',null);
Insert into AUTH_USER_REGISTRATION (USER_ID,USER_NAME,MAIL,FULLNAME,GENDER,USER_DAY,USER_MONTH,USER_YEAR,CREATED,STATUS,UU_ID,MOBILE,CHANGED) values (504,'casstifer','sir@gmail.com','Aditya Verma','male','25','December','1995',1406359633,'1','a4e8ad7b-a5f8-476b-a779-','742842',null);

质询：

SELECT
    user_id as user_id,
    user_name as user_name,
    mail as user_mail,
    fullname as full_name,
    case when (gender='male' or gender='mail' or gender='Male') then 'Male'
    when (gender='female' or gender='Female') then 'Female' else 'Others'
    end as gender,
    case
    when user_month='January' then '1'
    when user_month='February' then '2'
    when user_month='March' then '3'
    when user_month='April' then '4'
    when user_month='May' then '5'
    when user_month='June' then '6'
    when user_month='July' then '7'
    when user_month='August' then '8'
    when user_month='September' then '9'
    when user_month='Ocotober' then '10'
    when user_month='November' then '11'
    when user_month='December' then '12' 
    end user_month,
    case 
    when (user_day is not null or user_day<>'') and (user_month is not null or user_month<>'')   and (user_year is not null or user_year<>'') 
    then  user_day ||'-' || user_month ||'-' || user_year else '' end as dob,
    created,
    status as status,
    uu_id as uuid,
    mobile as mobile,
    changed 
FROM
    auth_user_registration;

型
我需要将user_day、user_month和user_year合并为一列，格式如下（01-01-2022），当前格式为（01-January-2022）。请帮助我完成此操作。