检查空表 [英] Check the empty table

问题描述

我只是想知道如果表是空的，将返回的数字是什么，没有记录

它是'0'？

解决方案

"数字？我确定有很多与桌子相关的数字。你的意思是哪一个？记录计数为零。


提示：感觉更安全。你有什么害处？构建两个是三个小表。其中一个没有记录。在其中一个中放入10条记录。为其中一个生成100,000条记录。使用这些进行测试。看看在10条记录上工作正常的例程如何比100,000预期的低得多可能很有启发性。

有两种情况，其中零点出现空表：


1.如果表的大小为零：

展开 | 选择 | 换行 | 行号

< blockquote>这里是我的案例

展开 | 选择 | Wrap | 行号

Hi,
I just want to know what is the number that will return if the table is empty "has no record"
Is it '' 0 '' ?

解决方案

"the number"? I''m sure there a many numbers associated with a table. Which one do you mean? Record count would be zero.

TIP: Feel safe to experiment more. What harm can you do? Build two are three small tables. Put no records in one of them. Put 10 records in one of them. Generate 100,000 records for one of them. Use these for your testing. It can be enlightening to see how routines that seem to work fine on 10 records are less than expected at 100,000.

There are two cases where zero comes on "empty table":

1. If table''s size is zero:

Expand|Select|Wrap|Line Numbers

Well here is my Case

Expand|Select|Wrap|Line Numbers

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