将SQL应用于DataTable [英] apply SQL to a DataTable

问题描述

你好，

我有这样的dataTable ......

I have a dataTable like this...

Col1，    Col2

Col1,    Col2

HAD    123

HAD    123

HAD    123

HAD    123

LEM      124

LEM     124

LEM      124

LEM     124

PLA      125

PLA     125

PLA      125

PLA     125

HAD    125

HAD    125

我想查询数据以选择每个具有1个以上不同col 2的col1。即HAD有123和125

I want to query the datable to select every col1 that has more than 1 distinct col 2. ie HAD has 123 and 125

如果它是一个真正的表，以下sql将工作..

If it were a real table the following sql would work..

SELECT distinct（col1）为col1，count（*）为col2 FROM myTable 

GROUP BY col1具有col2> 0

SELECT distinct(col1) as col1, count(*) as col2 FROM myTable 
GROUP BY col1 having col2 > 0

我只是不确定如何将其应用于dataTable。我无法看到如何使用带有复杂SQL语句的dataTable.Select（""）方法。

Im just not sure how to apply this to a dataTable. I cant see how I can use the dataTable.Select("") method with a complex SQL statement.

任何想法，

J

jppnn

推荐答案

DataTable不支持完整的SQL。 Select方法可用于过滤：

DataTable doesn't support full SQL. Select method can be used for filtering:

https://docs.microsoft.com/en-US/dotnet/api/system.data.datatable.select?view=netframework-4.7.2#System_Data_DataTable_Select_System_String_

https://www.csharp-examples.net/dataview-rowfilter/

https://www.csharp-examples.net/dataview-rowfilter/

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