循环使用动态SQL的列名

本文介绍了循环使用动态SQL的列名的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我刚刚想出了一个代码，以显示每个列的所有不同的值，并计算每个的记录数。我想让代码循环遍历所有列。

这是我迄今为止所做的...我是新来的，所以忍受noobness：）

硬码：

选择[销售经理]，count（*）$ [dbo]。[test] group by [Sales Manager] order by 2 desc

尝试使用动态SQL：

声明@sql varchar（max）， @column as varchar（255） set @column ='[Sales Manager]' set @sql ='select'+ @column +'，count（*）from [BT]。[dbo]。[test] group by'+ @column +'order by 2 desc' exec（@sql） pre>

这两个都可以正常工作。如何使其循环遍历所有列？我不介意，如果我必须硬编码列名称，它的工作方式是通过在每一个@column中的方式。

这是否有意义？ p>

感谢所有！

解决方案

您可以使用动态SQL并获取所有一个表的列名。然后建立脚本：

声明@sql varchar（max）=''将@tablename声明为varchar 255）='test' select @sql = @sql +'select ['+ c.name +']，count（*）as'''+ c.name +'''from ['+ t.name +'] group by ['+ c.name +'] order by 2 desc; '从sys.columns c 内部连接sys.tables t在c.object_id = t.object_id 其中t.name = @tablename EXEC（@ sql）

将 @tablename 更改为名称（没有数据库或模式名称）。

I just came up with an idea for a piece of code to show all the distinct values for each column, and count how many records for each. I want the code to loop through all columns.

Here's what I have so far... I'm new to SQL so bear with the noobness :)

Hard code:

select [Sales Manager], count(*) from [BT].[dbo].[test] group by [Sales Manager] order by 2 desc

Attempt at dynamic SQL:

Declare @sql varchar(max), @column as varchar(255) set @column = '[Sales Manager]' set @sql = 'select ' + @column + ',count(*) from [BT].[dbo].[test] group by ' + @column + 'order by 2 desc' exec (@sql)

Both of these work fine. How can I make it loop through all columns? I don't mind if I have to hard code the column names and it works its way through subbing in each one for @column.

Does this make sense?

Thanks all!

解决方案

You can use dynamic SQL and get all the column names for a table. Then build up the script:

Declare @sql varchar(max) = '' declare @tablename as varchar(255) = 'test' select @sql = @sql + 'select [' + c.name + '],count(*) as ''' + c.name + ''' from [' + t.name + '] group by [' + c.name + '] order by 2 desc; ' from sys.columns c inner join sys.tables t on c.object_id = t.object_id where t.name = @tablename EXEC (@sql)

Change @tablename to the name of your table (without the database or schema name).