English 中文(简体)
表格中储存的数值
原标题:SQL Dynamic SELECT statement from values stored in a table

我几天来一直在研究这一问题,并感到就像我正在圈子里一样。 我掌握了LQ的基本知识,但我不理解许多领域。

我有一个表格储存了我数据库中所有其他表格的名称和领域。

tblFields
===================================================

TableName      FieldName     BookmarkName  
---------------------------------------------------
Customer       FirstName     CustomerFirstName  
Customer       LastName      CustomerLastName  
Customer       DOB           CustomerDOB  

我想写一个<代码>SlectT的声明,如以下声明,但我无法开展工作:

SELECT (SELECT [FieldName] FROM [TableName]) FROM tblFields

这是可能的吗? 我开发的申请要求报告用户定制。

最佳回答

如果我正确理解你试图做些什么,那么你或许会更好做,因为你的方案有两个不同的问题。 你们想要选择哪些领域,然后在你们的方案中用来建立实际获得数据的第二个问题。

如果这项工作必须完全在结构库中进行,那么你将需要告诉我们你正在使用哪些数据库。 如果是服务器,你可能能够在第一个问询中使用一台 cur子,以建立你随后以间谍——外壳储存程序执行的第二个盘点。 但是,建议将其放在LQ之外。

问题回答

如果理解你试图做些什么,那么我认为这将有助于你。 这不是一件好事,它为2005年及以上服务器工作,但也许这是你所期待的:

declare @tableName nvarchar(100)
declare @sqlQuery nvarchar(max)
declare @fields varchar(500)
set @tableName =  YourTableName 
set @fields =   
select @fields = @fields + QUOTENAME(t.fieldname) +  ,  from (
select distinct fieldname from tblfields where tablename = @tableName)t


set @sqlQuery =  select   + left(@fields, LEN(@fields)-1) +   from   + QUOTENAME(@tableName)

execute sp_executesql @sqlQuery

Edit: As Martin suggested, i edited so that the columns and tablename are using QUOTENAME





相关问题
SQL SubQuery getting particular column

I noticed that there were some threads with similar questions, and I did look through them but did not really get a convincing answer. Here s my question: The subquery below returns a Table with 3 ...

难以执行 REGEXP_SUBSTR

I m 查询Oracle 10g。 我有两张表格(样本数据见下文)。 i m 试图提取一些领域

SQL Query Shortcuts

What are some cool SQL shorthands that you know of? For example, something I learned today is you can specify to group by an index: SELECT col1, col2 FROM table GROUP BY 2 This will group by col2

PHP array callback functions for cleaning output

I have an array of output from a database. I am wondering what the cleanest way to filter the values is example array Array ( [0] => Array ( [title] => title 1 ...

OracleParameter and DBNull.Value

we have a table in an Oracle Database which contains a column with the type Char(3 Byte). Now we use a parameterized sql to select some rows with a DBNull.Value and it doesn t work: OracleCommand ...

Running numbers in SQL

I have a SQL-statement like this: SELECT name FROM users WHERE deleted = 0; How can i create a result set with a running number in the first row? So the result would look like this: 1 Name_1 2 ...

How to get SQL queries for each user where env is production

I’m developing an application dedicated to generate statistical reports, I would like that user after saving their stat report they save sql queries too. To do that I wrote the following module: ...

热门标签