C＃的DataTable内连接与动态列 [英] C# DataTable Inner join with dynamic columns
问题描述
我想加入两个DataTable一起以同样的方式对这个问题：
I'm trying to join two DataTables together in a similar way to this question:
我想要得到的输出是一个单一的组合拳表中，与来自原始表的列。他们都有一个共同的日期戳列。
I'm trying to get the output to be a single 'combined' table, with columns from both of the original tables. They will both have a datestamp column in common.
给出的答案是良好的数据表与固定列，但如果他们是动态创建的内容，并且可以有任意数量的列，我怎么能加入他们的行列？
The answer given is good for DataTables with fixed columns, but what if they are created dynamically, and can have any number of columns, how can I join them?
例如。
T1 (datestamp, t1Column1, t1Column2, t1ColumnN...)
T2 (datestamp, t2Column1, t2Column2, t2ColumnN...)
我想加入到创建以下内容：
I would like to join to create the following:
J1 (datestamp, t1Column1, t1Column2, t1ColumnN, ..., t2Column1, t2Column2, t2ColumnN...)
这可能吗？
推荐答案
我发现它不依赖于通过列循环的解决方案。
I found a solution which doesn't rely on looping through the columns.
它采用了合并的方法，我有previously驳回，因为我认为这两个表所需要的相同的结构。
It uses the 'Merge' method, which I had previously dismissed as I thought both tables required the same structure.
首先，您需要创建的两个数据表的主键：
First you need to create a primary key on the two data-tables:
// set primary key
T1.PrimaryKey = new DataColumn[] { T1.Columns["DateStamp"] };
T2.PrimaryKey = new DataColumn[] { T2.Columns["DateStamp"] };
接着两个表添加一个数据设定一个关系可以添加：
Then add both tables to a data-set so a relationship can be added:
// add both data-tables to data-set
DataSet dsContainer = new DataSet();
dsContainer.Tables.Add(T1);
dsContainer.Tables.Add(T2);
接下来，添加数据集的两个关键列之间的关系：
Next add the relationship between the two key columns in the data-set:
// add a relationship between the two timestamp columns
DataRelation relDateStamp = new DataRelation("Date", new DataColumn[] { T1.Columns["DateStamp"] }, new DataColumn[] { T2.Columns["DateStamp"] });
dsContainer.Relations.Add(relDateStamp);
最后，你可以第一个数据表，现在复制到一个新的组合拳的版本，然后在第二个合并：
Finally you can now copy the first data-table into a new 'combined' version, and then merge in the second:
// populate combined data
DataTable dtCombined = new DataTable();
dtCombined = T1.Copy();
dtCombined.Merge(T2, false, MissingSchemaAction.Add);
注：合并方法需要第二个参数是假的，否则它复制结构，但第二个表中没有数据。
Note: The Merge method requires the second argument to be false or else it copies the structure but not the data of the second table.
这会再结合下面的表格：
This would then combine the following tables:
T1 (2012-05-09, 111, 222)
T2 (2012-05-09, 333, 444, 555)
成基于主密钥的组合的版本：
into a combined version based on the primary-key:
J1 (2012-05-09, 111, 222, 333, 444, 555)
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