如果不存在Oracle,则插入

对于oracle 11.2.0.1,有一个 这可以做到:

insert /*+ IGNORE_ROW_ON_DUPKEY_INDEX(customer_orders,pk_customer_orders) */
  into customer_orders
       (order_id, customer, product)
values (    1234,     9876,  'K598')
     ;

better approaches

第一种方法——直接翻译上述语义提示:

begin
  insert into customer_orders
         (order_id, customer, product)
  values (    1234,     9876,  'K698')
  ;
  commit;
exception
  when DUP_VAL_ON_INDEX
  then ROLLBACK;
end;

当存在大量争议时,速度比上述两个提示都快:

begin
    select count (*)
    into   l_is_matching_row
    from   customer_orders
    where  order_id = 1234
    ;

    if (l_is_matching_row = 0)
    then
      insert into customer_orders
             (order_id, customer, product)
      values (    1234,     9876,  'K698')
      ;
      commit;
    end if;
exception
  when DUP_VAL_ON_INDEX
  then ROLLBACK;
end;

ses1:

create table t1 (pk int primary key, i int);
create table t11 (pk int primary key, i int);
insert into t1 values(1, 1);
insert into t11 values(2, 21);
insert into t11 values(3, 31);
commit;

ses2: insert into t1 values(2, 2);

ses1:

MERGE INTO t1 d
USING t11 s ON (d.pk = s.pk)
WHEN NOT MATCHED THEN INSERT (d.pk, d.i) VALUES (s.pk, s.i);

ses2: commit;

ses1: ORA-00001

我们可以把 DUAL 和 NOT EXISTS

INSERT INTO schema.myFoo ( 
    primary_key, value1, value2
) 
SELECT
    'bar', 'baz', 'bat' 
FROM DUAL
WHERE NOT EXISTS (
    SELECT 1 
    FROM schema.myFoo
    WHERE primary_key = 'bar'
);

这仅在要插入的项目不存在时插入。

if not exists (...) insert ... 

在T-SQL中

insert into destination (DESTINATIONABBREV) 
  select 'xyz' from dual 
  left outer join destination d on d.destinationabbrev = 'xyz' 
  where d.destinationid is null;

如果您不想从其他表合并,而是插入新数据。..我想出了这个。也许有更好的方法吗?

MERGE INTO TABLE1 a
    USING DUAL
    ON (a.C1_pk= 6)
WHEN NOT MATCHED THEN
    INSERT(C1_pk, C2,C3,C4)
    VALUES (6, 1,0,1);

然后

insert myFoo
  select *
     from t
       where t.primary_key not in ( select primary_key from myFoo) 

如果插入的新数据很少,这不是最好的,因为您已经通过线路复制了所有数据。

DECLARE
   tmp NUMBER(3,1);
BEGIN
  SELECT COUNT(content_id) INTO tmp FROM contents WHERE (condition);
  if tmp != 0 then
    INSERT INTO contents VALUES (...);
  else
    INSERT INTO contents VALUES (...);
  end if;
END;

我使用了上面的代码。它很长,但很简单,对我来说很有用。类似于迈克尔的代码。

如果你的表与其他表“独立”(我的意思是,它不会触发级联删除,也不会将任何外键关系设置为null),一个很好的技巧可能是先删除行,然后再插入。它可能是这样的:

从MyTable中删除prop1='aa';//假设它最多只选择一行!

如果你删除了不存在的东西,什么都不会发生。

这是对erikkallen发表的评论的回答:

你不需要临时工作台。如果你 只有几行,(从中选择1行 双UNION SELECT 2 FROM dual)将 更新索引键上的锁,而不是 继续,直到Sess1满足以下任一条件

好吧,你自己试试,告诉我你是否会遇到同样的错误:

ses1:

create table t1 (pk int primary key, i int);
create table t11 (pk int primary key, i int);
insert into t1 values(1, 1);
insert into t11 values(2, 21);
insert into t11 values(3, 31);
commit;

ses2: insert into t1 values(2, 2);

ses1:

MERGE INTO t1 d
USING t11 s ON (d.pk = s.pk)
WHEN NOT MATCHED THEN INSERT (d.pk, d.i) VALUES (s.pk, s.i);

ses2: commit;

ses1: ORA-00001

INSERT INTO schema.myFoo ( primary_key        , value1          , value2         )
                         SELECT 'bar1' AS primary_key ,'baz1' AS value1 ,'bat1' AS value2 FROM DUAL WHERE (SELECT 1 AS value FROM schema.myFoo WHERE LOWER(primary_key) ='bar1' AND ROWNUM=1) is null;