为何要逐一对比? 用 select count(*) from [TABLE] where [COLUMN] = 'VALUE' 判断返回的是不是0不就行了么?
为何要逐一对比? 用 select count(*) from [TABLE] where [COLUMN] = 'VALUE' 判断返回的是不是0不就行了么?
var max = 1000000; List<int> l =new List<int>(); for (int i = 0; i < max; i++) { l.Add(i+1); } var x = ""; var u = max/2; var y = max % 2; var t = u + y; for (int i = 0; i < max; i=i+2) { x += l[i].ToString()+","; if (y == 0) { x += l[i+1].ToString()+","; } else { if((i+1)<max) x += l[t - (u - i)].ToString() + ","; }; }你看我循环走了几回
select * from [TABLE] where id in (select id from [TABLE] group by id having count(*) > 1)
用
select count(*) from [TABLE] where [COLUMN] = 'VALUE'
判断返回的是不是0不就行了么?
用
select count(*) from [TABLE] where [COLUMN] = 'VALUE'
判断返回的是不是0不就行了么?
List<int> l =new List<int>();
for (int i = 0; i < max; i++)
{
l.Add(i+1);
}
var x = "";
var u = max/2;
var y = max % 2;
var t = u + y;
for (int i = 0; i < max; i=i+2)
{
x += l[i].ToString()+",";
if (y == 0)
{
x += l[i+1].ToString()+",";
}
else
{
if((i+1)<max)
x += l[t - (u - i)].ToString() + ",";
};
}你看我循环走了几回
select * from [TABLE] where id in (select id from [TABLE] group by id having count(*) > 1)
select count(1) from table
where x=@x and y=@y and z=@z
把要插入的字段都比较一次~
虽然在数据库也像for循环,......
至于怎么循环还是其他的你自己多作实验,看看那个是你要的
要不就在说清楚些
我是根据,楼上写的方法改进的
我把当前id进行分析,然后得出一个范围
两边排序后在进行折半散粉,都给一个不太合适,大家都出力了写sql的不给了,我个方法根本写不了sql