检查表是否没有记录，然后在表中插入3条记录

Question

我想检查表是否没有记录，然后只在表中为sql server和oracle插入3条记录。

Answer 1

什么用这样的问题..从部分

尝试..

int count = select count(*) from table-name; 
if(count==0){ 
    //your insert statements as many as 
    insert into table-name values(); 
} 

Answer 2

您需要做的仅仅是这样的：

IF (Select count(*) from tablename) = 0 
BEGIN 
    -- INSERT VALUES 
END 

Answer 3

，如果你想在单个插入句子中插入值，您可以这样做：

insert into yourTable (yourFields) 
select value1 as yourField1, ... 
where (select count(*) from yourTable) =0 

Testing：

create table #t (k int); 

insert into #t 
select 1 
where (select count(*) from #t) =0 

insert into #t 
select 2 as k; 

insert into #t 
select 3 
where (select count(*) from #t) =0 

select * from #t; 

注意，只有 '1' 和 '2' 被插入，而不是 '3'。

Answer 4

这种类型的结构将在SQL Server和Oracle工作：

SQL> insert into t34 
    2 select * from emp where id <= 3 
    3 and 0 in (select count(*) from t34) 
    4/

3 rows created. 

SQL> r 
    1 insert into t34 
    2 select * from emp where rownum <= 3 
    3* and 0 in (select count(*) from t34) 

0 rows created. 

SQL> 

但是否能解决你的问题实际上取决于你的三排的来源。