mybatis插入Oracle主鍵(自增鍵)

      在mybatis插件oracle數據庫，如果是主鍵自增型的，就要考慮是已經有觸發器處理，還是隻有sequence，這樣才能在保存後的類裏面主鍵纔有值。

1、只有sequence時，demo如下

declare
V_NUM number;
BEGIN
  V_NUM := 0;
  ----判斷序列是否存在（區分大小寫）
  select count(0) into V_NUM from user_sequences where sequence_name=upper('S_SYS_USER'); 
  ----如果存在立即刪除
  if V_NUM > 0 then
    execute immediate 'DROP SEQUENCE S_SYS_USER';
  end if;
END;
/

--創建序號的規則
create sequence S_SYS_USER
  INCREMENT BY 1   -- 每次加幾個  
  START WITH 1     -- 從1開始計數  
  NOMAXVALUE       -- 不設置最大值  
  NOCYCLE ;         -- 一直累加，不循環
/

<insert id="save" parameterType="com.bootdo.system.domain.UserDO">
    	<selectKey resultType="long" keyProperty="userId" order="BEFORE"> 
	        SELECT S_SYS_USER.NEXTVAL FROM DUAL 
	    </selectKey> 
		insert into sys_user
		(
			username, 
			name, 
			password, 
		)
		values
		(
			#{username,jdbcType=VARCHAR}, 
			#{name,jdbcType=VARCHAR}, 
			#{password,jdbcType=VARCHAR}
		)
	</insert>

 

2、通過Oracle觸發器

declare
V_NUM number;
BEGIN
  V_NUM := 0;
  ----判斷序列是否存在（區分大小寫）
  select count(0) into V_NUM from user_sequences where sequence_name=upper('S_SYS_USER'); 
  ----如果存在立即刪除
  if V_NUM > 0 then
    execute immediate 'DROP SEQUENCE S_SYS_USER';
  end if;
END;
/

--創建序號的規則
create sequence S_SYS_USER
  INCREMENT BY 1   -- 每次加幾個  
  START WITH 1     -- 從1開始計數  
  NOMAXVALUE       -- 不設置最大值  
  NOCYCLE ;         -- 一直累加，不循環
/

--創建觸發器  DROP TRIGGER TIB_SYS_USER  --刪除觸發器
create or replace trigger TIB_SYS_USER before insert on SYS_USER for each row
declare
    integrity_error  exception;
    errno            integer;
    errmsg           char(200);
    dummy            integer;
    found            boolean;
begin
    select S_SYS_USER.NEXTVAL INTO :new.user_id from dual;
exception
    when integrity_error then
       raise_application_error(errno, errmsg);
end;

 

<insert id="save" parameterType="com.bootdo.system.domain.UserDO">
    	<selectKey resultType="long" keyProperty="userId" order="AFTER"> 
	        SELECT S_SYS_USER.CURRVAL FROM DUAL 
	    </selectKey> 
		insert into sys_user
		(
			username, 
			name, 
			password
		)
		values
		(
			#{username,jdbcType=VARCHAR}, 
			#{name,jdbcType=VARCHAR}, 
			#{password,jdbcType=VARCHAR}
		)
	</insert>

@Transactional
    @Override
    public int save(UserDO user) {
        int count = userMapper.save(user);
        //這樣userid纔能有值
        Long userId = user.getUserId();
        return count;
    }