今天在删除一个车辆品牌表的时候，遇到了一个问题，是在java的代码中做逻辑删除还是直接在Oracle中一次删除完成呢

思来想去觉得还是在sql里直接删除比较合适，

为什么呢？

第一，涉及数据库的读写操作一定要遵从ACID原则，

第二，java中操作单个删除太麻烦，而且占用内存，多次打开数据库链接，造成资源浪费

第三，好久没写储存过程了，太咸

下面是这个表的结构

create table T_BRAND_CLASS 
(
   ID                   VARCHAR2(32)         not null,
   BRAND_NAME           VARCHAR2(100),
   BRAND_IMG            VARCHAR2(32),
   BRAND_INITLAL        VARCHAR2(10),
   BRAND_ISHOT          VARCHAR2(10),
   BRAND_ISSTICK        VARCHAR2(10),
   constraint PK_T_BRAND_CLASS primary key (ID)
         USING INDEX  ENABLE
);

comment on table T_BRAND_CLASS is
'品牌分类';

 

create table T_BRAND_TYPE 
(
   ID                   VARCHAR2(32)         not null,
   BRAND_CLASS_ID       VARCHAR2(32),
   TYPE_NAME            VARCHAR2(100),
   constraint PK_T_BRAND_TYPE primary key (ID)
         USING INDEX  ENABLE
);

comment on table T_BRAND_TYPE is
'品牌型号';
create table T_BRAND_SPECIFICATION 
(
   ID                   VARCHAR2(32)         not null,
   BRAND_ID             VARCHAR2(32),
   BRAND_CC             VARCHAR2(32),
   CC_TYPE              NUMBER,
   constraint PK_T_BRAND_SPECIFICATION primary key (ID)
         USING INDEX  ENABLE
);

comment on table T_BRAND_SPECIFICATION is
'品牌规格';
create table T_BRAND_SERIES 
(
   ID                   VARCHAR2(32)         not null,
   SERIES_NAME          VARCHAR2(100),
   SPECIFCATION_ID      VARCHAR2(32),
   SERIES_YEAR          VARCHAR2(10),
   constraint PK_T_BRAND_SERIES primary key (ID)
         USING INDEX  ENABLE
);

comment on table T_BRAND_SERIES is
'品牌车系';

 

大概的可以看出来这个一个树状结构的表，彼此的关联就是一个对方的id，温习了下储存过程常用的关键字

cursor ：游标 紧跟后面的sql查询的结果会自动给定义的变量赋值，数据结构类似lua里的table，
BEGIN：BEGIN和end之间的代码会动态的执行；
for .. in .. loop:循环
v_sql VARCHAR2(1000);：定义数据类型
v_sql:= :赋值方式
execute immediate .aa.USING bb :aa是一个要执行的sql语句，bb是一个aa中的输出占位符填充数据

看完上面大概后一个简单的储存过程就可以写出来了，如下传入一个表名的id 就可以删除对应表数据下面的所有关联数据


create or replace PROCEDURE DEL_brand_class(istable_id  in VARCHAR2) 
is  
v_sql VARCHAR2(1000);
typeid VARCHAR2(1000);
speid VARCHAR2(1000);
serid VARCHAR2(1000);
cursor cur_tableid is
 select a.id as id,
  b.id as typeid,
  c.id as speid,
  d.id as serid
  from t_brand_class a
  left join T_BRAND_TYPE  b on a.id = b.BRAND_CLASS_ID
  left join T_BRAND_SPECIFICATION   c on b.id = c.BRAND_ID
  left join T_BRAND_SERIES d on c.ID = d.SPECIFCATION_ID
  where a.id = istable_id;
BEGIN
 for rec_id in cur_tableid loop

  v_sql:='delete from t_brand_class where id =:1';
  typeid:='delete from T_BRAND_TYPE where id = :1';
  speid:='delete from T_BRAND_SPECIFICATION where id = :1';
  serid:='delete from T_BRAND_SERIES where id = :1';
  execute immediate v_sql USING rec_id.id;
    execute immediate typeid USING rec_id.typeid;
      execute immediate speid USING rec_id.speid;
        execute immediate serid USING rec_id.serid;
  end loop;
commit;
END DEL_brand_class;

 

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