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How to merge two datatables in c# (without any common identifier)?8

I am trying to merge two data table dt and dt4. I want to merge 2 data tables, having different schemas, and no common identifier together. Becuase the first data table dt contains some values.I get dt count on x. Based on that count I have to fetch some value table and stored in dt4. if if dt contains 3 row value then x=3 and dt4 contains 3 values. After these process I have to merge dt and dt4 and displayed as one table.
While using the given below code getting one error. The error is : "'column' argument cannot be null." Help me to find a proper soluion. Thank you.
Code:
protected void ddlCircle_SelectedIndexChanged(object sender, EventArgs e)
{
ShadingAnalysisDataSetTableAdapters.tbl_CadEngineersTeamTableAdapter cd;
cd = new ShadingAnalysisDataSetTableAdapters.tbl_CadEngineersTeamTableAdapter();
DataTable dt = new DataTable();
dt = cd.GetAvailableData(ddlCircle.SelectedValue); // Getting details of unassigned site
int x, y;
DataTable dt3 = new DataTable();
dt3 = cd.GetTeam();
y = dt3.Rows.Count;
x = dt.Rows.Count; // counting the unassinged sites
DataTable dt2 = new DataTable();
dt2 = cd.GetAssignTeam(x); //Getting team based on count
string[] arr = new string[dt2.Rows.Count];
int i = 0;
foreach (DataRow r in dt2.Rows)
{
arr[i] = r["Team"].ToString(); // assigning available team to array
i++;
}
string[] strArr = new string[x+1]; // another array to copy arr values.
i = 0; int j = 0;
while (j <= x)
{
strArr[j]= arr[i] ; // copying the arr[] values into strArr[] based on count.
i++;
j++;
if (i == y)
{
i = 0;
}
}
DataTable dt4 = new DataTable();
dt4.Columns.Add("Team");
foreach (string s in strArr)
{
dt4.Rows.Add(s); // Converting string array strArr[] to data table dt4
}
dt.Merge(dt4); // error poppup here. Error : 'column' argument cannot be null.
GridView2.DataSource = dt;
GridView2.DataBind();
}
dt contain
State District SiteID SiteName
----- -------- ------ --------
Sate1 District1 1001 A
Sate2 District2 1002 B
Sate3 District3 1003 C
dt4 contain
Team
-----
Team1
Team2
Team3
I need a final output as:
State District SiteID SiteName Team
----- -------- ------ -------- -----
Sate1 District1 1001 A Team1
Sate2 District2 1002 B Team2
Sate3 District3 1003 C Team3

Do you have relationship. If you have primary key ID in First Table and you can add ID column in Second Table
See here MSDN Article Merge Datatables

If you add a relationship between the 2 datatables, like a common identifier - you would be able to extract the common columns between datatables automatically using Linq.
Something like the following;
var commonColumns = dt1.Columns.OfType<DataColumn>().Intersect(dt2.Columns.OfType<DataColumn>(), new DataColumnComparer());
DataTable result = new DataTable();
dt1.PrimaryKey = commonColumns.ToArray();
result.Merge(dt1, false, MissingSchemaAction.AddWithKey);
result.Merge(dt2, false, MissingSchemaAction.AddWithKey);
Have a look at a previous question about this Full outer join, on 2 data tables, with a list of columns

The given code is working perfectly. Thank you for all valuable comments.
Code :
protected void ddlCircle_SelectedIndexChanged(object sender, EventArgs e)
{
ShadingAnalysisDataSetTableAdapters.tbl_CadEngineersTeamTableAdapter cd;
cd = new ShadingAnalysisDataSetTableAdapters.tbl_CadEngineersTeamTableAdapter();
DataTable dt = new DataTable();
dt = cd.GetAvailableData(ddlCircle.SelectedValue); // Getting details of unassigned site
int x, y;
DataTable dt3 = new DataTable();
dt3 = cd.GetTeam();
y = dt3.Rows.Count;
x = dt.Rows.Count; // counting the unassinged sites
DataTable dt2 = new DataTable();
dt2 = cd.GetAssignTeam(x); //Getting team based on count
string[] arr = new string[dt2.Rows.Count];
int i = 0;
foreach (DataRow r in dt2.Rows)
{
arr[i] = r["Team"].ToString(); // assigning available team to array
i++;
}
string[] strArr = new string[x+1]; // another array to copy arr values.
i = 0; int j = 0;
while (j <= x)
{
strArr[j]= arr[i] ; // copying the arr[] values into strArr[] based on count.
i++;
j++;
if (i == y)
{
i = 0;
}
}
DataTable dt4 = new DataTable();
dt4.Columns.Add("Team");
foreach (string s in strArr)
{
dt4.Rows.Add(s); // Converting string array strArr[] to data table dt4
}
//Adding new data table for merging two table details
DataTable dt7 = new DataTable();
//create columns and copy data from dt:
dt7 = dt.Copy();
foreach (DataColumn column in dt4.Columns)
dt7.Columns.Add(column.ColumnName, typeof(string));
//copy data from dt4:
foreach (DataRow row in dt4.Rows)
{
dt7.Rows[dt4.Rows.IndexOf(row)][5] = row[0];
}
GridView3.DataSource = dt7;
GridView3.DataBind();
}

You don't have relationship with table dt and table dt4.
Problem::You are facing this error because you dont have any relation between these two data tables.
I think you better start by adding relationship first. If you have primary key ID in dt and you can add ID column in dt4 with the relevant ID.
So first create a column in both tables which is common and then on basis of that relationship
you can use DataTable.Merge method directly

Combining n DataTables into a Single DataTable

All, there are some question on this, but I can't seem to extract enough information to solve the problem for my case. I extract an unknown number of tables into SQL Server 'Tab1', 'Tab2', 'Tab3', ... , 'TabN'. The columns in these tables are different, but the row definitions are the same. I need to pull all the data in from the Server into N DataTables and then combine these to form a single DataTable. What I do currently is
int nTmpVolTabIdx = 1;
strSqlTmp = String.Empty;
using (DataTable dataTableALL = new DataTable())
{
while (true)
{
string strTmpVolName = String.Format("Tab{0}", nTmpVolTabIdx);
strSqlTmp = String.Format("SELECT * FROM [{0}];", strTmpVolName);
// Pull the data from 'VolX' into a local DataTable.
using (DataTable dataTable = UtilsDB.DTFromDB(conn, strTmpVolName, strSqlTmp, false))
{
if (dataTable == null)
break;
else
dataTableALL.Merge(dataTable);
}
nTmpVolTabIdx++;
}
...
}
This merges the DataTables but they are miss-aligned (padding blank cells onto the appended data set). I could append the columns of the new DataTable via a loop; but is there an easier/nicer way to do this (perhaps using LINQ)?
Thanks for your time.
Edit. To provide the example data sets.
What I required is
The individual tables are
After the first Merge operation I have the following
Thanks again.

The table has repeating primary keys after the Merge because no primary-key was defined. So either specify the PK or try this method here which i've written from scratch(so it's not really tested):
public static DataTable MergeAll(this IList<DataTable> tables, String primaryKeyColumn)
{
if (!tables.Any())
throw new ArgumentException("Tables must not be empty", "tables");
if(primaryKeyColumn != null)
foreach(DataTable t in tables)
if(!t.Columns.Contains(primaryKeyColumn))
throw new ArgumentException("All tables must have the specified primarykey column " + primaryKeyColumn, "primaryKeyColumn");
if(tables.Count == 1)
return tables[0];
DataTable table = new DataTable("TblUnion");
table.BeginLoadData(); // Turns off notifications, index maintenance, and constraints while loading data
foreach (DataTable t in tables)
{
table.Merge(t); // same as table.Merge(t, false, MissingSchemaAction.Add);
}
table.EndLoadData();
if (primaryKeyColumn != null)
{
// since we might have no real primary keys defined, the rows now might have repeating fields
// so now we're going to "join" these rows ...
var pkGroups = table.AsEnumerable()
.GroupBy(r => r[primaryKeyColumn]);
var dupGroups = pkGroups.Where(g => g.Count() > 1);
foreach (var grpDup in dupGroups)
{
// use first row and modify it
DataRow firstRow = grpDup.First();
foreach (DataColumn c in table.Columns)
{
if (firstRow.IsNull(c))
{
DataRow firstNotNullRow = grpDup.Skip(1).FirstOrDefault(r => !r.IsNull(c));
if (firstNotNullRow != null)
firstRow[c] = firstNotNullRow[c];
}
}
// remove all but first row
var rowsToRemove = grpDup.Skip(1);
foreach(DataRow rowToRemove in rowsToRemove)
table.Rows.Remove(rowToRemove);
}
}
return table;
}
You can call it in this way:
var tables = new[] { tblA, tblB, tblC };
DataTable TblUnion = tables.MergeAll("c1");
Used this sample data:
var tblA = new DataTable();
tblA.Columns.Add("c1", typeof(int));
tblA.Columns.Add("c2", typeof(int));
tblA.Columns.Add("c3", typeof(string));
tblA.Columns.Add("c4", typeof(char));
var tblB = new DataTable();
tblB.Columns.Add("c1", typeof(int));
tblB.Columns.Add("c5", typeof(int));
tblB.Columns.Add("c6", typeof(string));
tblB.Columns.Add("c7", typeof(char));
var tblC = new DataTable();
tblC.Columns.Add("c1", typeof(int));
tblC.Columns.Add("c8", typeof(int));
tblC.Columns.Add("c9", typeof(string));
tblC.Columns.Add("c10", typeof(char));
tblA.Rows.Add(1, 8500, "abc", 'A');
tblA.Rows.Add(2, 950, "cde", 'B');
tblA.Rows.Add(3, 150, "efg", 'C');
tblA.Rows.Add(4, 850, "ghi", 'D');
tblA.Rows.Add(5, 50, "ijk", 'E');
tblB.Rows.Add(1, 7500, "klm", 'F');
tblB.Rows.Add(2, 900, "mno", 'G');
tblB.Rows.Add(3, 150, "opq", 'H');
tblB.Rows.Add(4, 850, "qrs", 'I');
tblB.Rows.Add(5, 50, "stu", 'J');
tblC.Rows.Add(1, 7500, "uvw", 'K');
tblC.Rows.Add(2, 900, "wxy", 'L');
tblC.Rows.Add(3, 150, "yza", 'M');
tblC.Rows.Add(4, 850, "ABC", 'N');
tblC.Rows.Add(5, 50, "CDE", 'O');
After DataTable.Merge in MergeAll:
After some modifications to join the rows in MergeAll:
Update
Since this question arose in one of the comments, if the only relation between two tables is the index of a DataRow in the table and you want to merge both tables according to the index:
public static DataTable MergeTablesByIndex(DataTable t1, DataTable t2)
{
if (t1 == null || t2 == null) throw new ArgumentNullException("t1 or t2", "Both tables must not be null");
DataTable t3 = t1.Clone(); // first add columns from table1
foreach (DataColumn col in t2.Columns)
{
string newColumnName = col.ColumnName;
int colNum = 1;
while (t3.Columns.Contains(newColumnName))
{
newColumnName = string.Format("{0}_{1}", col.ColumnName, ++colNum);
}
t3.Columns.Add(newColumnName, col.DataType);
}
var mergedRows = t1.AsEnumerable().Zip(t2.AsEnumerable(),
(r1, r2) => r1.ItemArray.Concat(r2.ItemArray).ToArray());
foreach (object[] rowFields in mergedRows)
t3.Rows.Add(rowFields);
return t3;
}
Sample:
var dt1 = new DataTable();
dt1.Columns.Add("ID", typeof(int));
dt1.Columns.Add("Name", typeof(string));
dt1.Rows.Add(1, "Jon");
var dt2 = new DataTable();
dt2.Columns.Add("Country", typeof(string));
dt2.Rows.Add("US");
var dtMerged = MergeTablesByIndex(dt1, dt2);
The result table contains three columns ID,Name,Country and a single row: 1 Jon US

DataTable Join or Merge

I have 3 Data tables populated with a dataset and table adapters/ binding sources and i need to run a Join query or find another way to get specific data. (the dataset contains each table listed)
Tables:
Product Table:
Prod_ID Name
1 tv
2 couch
Consumer Table:
Con_Id Name City
----------------------
1 Gray New York
2 Joe Chicago
3 Steve Madison
Transactions Table
Tran_Id Con_ID Prod_ID Price
-------------------------------------
1 2 1 900
2 1 2 300
Given a product name i need to populate a table with each distinct city and how much that product has sold for in that city (add all prices for that product to any consumer in a given city)
I am really stumped and cant find a way. (i have tried alot)
Please help and thank you!
Nudiers approach so far:
DataRelation relation = null;
DataColumn table1Column = null;
DataColumn table2Column = null;
DataColumn table3Column = null;
table1Column = tlobergeDataSet.Tb_Product.Columns[0];
table2Column = tlobergeDataSet.Tb_Transactions.Columns[3];
table3Column = tlobergeDataSet.Tb_Consumer.Columns[0];
relation = new DataRelation("relation", table1Column, table2Column);
tlobergeDataSet.Relations.Add(relation);

public DataTable MergeTables(DataTable dtFirst, DataTable dtSecond, string CommonColumn)
{
DataTable dtResults = dtFirst.Clone();
int count = 0;
for (int i = 0; i < dtSecond.Columns.Count; i++)
{
if (!dtFirst.Columns.Contains(dtSecond.Columns[i].ColumnName))
{
dtResults.Columns.Add(dtSecond.Columns[i].ColumnName, dtSecond.Columns[i].DataType);
count++;
}
}
DataColumn[] columns = new DataColumn[count];
int j = 0;
for (int i = 0; i < dtSecond.Columns.Count; i++)
{
if (!dtFirst.Columns.Contains(dtSecond.Columns[i].ColumnName))
{
columns[j++] = new DataColumn(dtSecond.Columns[i].ColumnName, dtSecond.Columns[i].DataType);
}
}
dtResults.BeginLoadData();
foreach (DataRow dr in dtFirst.Rows)
{
dtResults.Rows.Add(dr.ItemArray);
}
foreach (DataRow dr in dtSecond.Rows)
{
foreach (DataRow dr1 in dtResults.Rows)
{
if (dr1[CommonColumn].ToString().Equals(dr[CommonColumn].ToString()))
{
foreach (DataColumn c in columns)
{
dr1[c.ColumnName] = dr[c.ColumnName];
}
}
}
}
dtResults.EndLoadData();
return dtResults;
}

try with this.
DataRelation relation = null;
DataColumn table1Column = null;
DataColumn table2Column = null;
//retrieve column
table1Column = ds.Tables("Table1").Columns(0);
table2Column = ds.Tables("table2").Columns(0);
//relating tables
relation = new DataRelation("relation", table1Column, table2Column);
//assign relation to dataset
ds.Relations.Add(relation);

You can only relate two tables in a DataRelation object and to access the data from
the dataset is straightforward because the data has been already related.
DataRelation relation = null;
DataColumn table1Column = null;
DataColumn table2Column = null;
DataColumn table3Column = null;
table1Column = tlobergeDataSet.Tb_Product.Columns[0];
table2Column = tlobergeDataSet.Tb_Transactions.Columns[2];
table2Column1 = tlobergeDataSet.Tb_Transactions.Columns[1];
table3Column = tlobergeDataSet.Tb_Consumer.Columns[0];
relation = new DataRelation("relation", table1Column, table2Column);
tlobergeDataSet.Relations.Add(relation);
relation = new DataRelation("relation1", table3Column , table2Column1);
tlobergeDataSet.Relations.Add(relation);

In LINQ, you can join the tables to find the data you want with syntax like so:
from a in keyTable
join b in anotherTable on a.Key equals b.Key
join c in aThirdTable on a.Key equals c.Key
select new
{
// Anonymous Object Properties using identifier a, b, and c to get data
};
You should be able to take that snippet and generate a linq query that will generate an anonymous object containing the specific data representation that you need.

Why won't two Identical DataTables show any differences?

I am using DataRelation to compare two DataTable and return a third table containing the rows that are not share by both original tables by using this tutorial. Below is the code.
public static DataTable Difference(DataTable First, DataTable Second)
{
//Create Empty Table
DataTable table = new DataTable("Difference");
//Must use a Dataset to make use of a DataRelation object
using(DataSet ds = new DataSet())
{
//Add tables
ds.Tables.AddRange(new DataTable[]{First.Copy(),Second.Copy()});
//Get Columns for DataRelation
DataColumn[] firstcolumns = new DataColumn[ds.Tables[0].Columns.Count];
for(int i = 0; i < firstcolumns.Length; i++)
{
firstcolumns[i] = ds.Tables[0].Columns[i];
}
DataColumn[] secondcolumns = new DataColumn[ds.Tables[1].Columns.Count];
for(int i = 0; i < secondcolumns.Length; i++)
{
secondcolumns[i] = ds.Tables[1].Columns[i];
}
//Create DataRelation
DataRelation r = new DataRelation(string.Empty,firstcolumns,secondcolumns,false);
ds.Relations.Add(r);
//Create columns for return table
for(int i = 0; i < First.Columns.Count; i++)
{
table.Columns.Add(First.Columns[i].ColumnName, First.Columns[i].DataType);
}
//If First Row not in Second, Add to return table.
table.BeginLoadData();
foreach(DataRow parentrow in ds.Tables[0].Rows)
{
DataRow[] childrows = parentrow.GetChildRows(r);
if(childrows == null || childrows.Length == 0)
table.LoadDataRow(parentrow.ItemArray,true);
}
table.EndLoadData();
}
return table;
}
Surprisingly enough when I exercised this code, it only worked on few cases and failed in others.
There was one case, I was comparing two identical table (but has different source) that both has:
Same Column Name & DataType
Same Number of Rows & Columns
Same Value in Each Cells
Only to have a brand new table returned that actually has the exact same composition as the two original tables!
What did I possibly miss?
Is it possible that two identical tables (sharing features I mentioned above) can have other different properties (which doesn't seem visible to users' eyes)?
Or is it possible that this is actually a bad method? What are the possible alternatives?
EDITED
Both tables have same primitive datatype such as: System.String, System.Int32, System.DateTime
These code doesn't work on all samples I tested
Here is a print screen of 1 sample (using DataSet Visualizer)

I had to write something similar once and this is the approach I used:
First this approach only works if you don't have duplicate rows in each table.
Using primary keys..
First.PrimaryKey = firstcolumns;
Second.PrimaryKey = secondcolumns; //These throw exceptions when you have duplicate rows
Then..
foreach (DataRow dr in Second.Rows)
{
List<Object> l = new List<Object>();
foreach (DataColumn dc in secondcolumns) l.Add(dr[dc]);
if (First.Rows.Find(l.ToArray()) == null) //NOT FOUND
{
table.Rows.Add(l.ToArray());
}
}
foreach (DataRow dr in First.Rows)
{
List<Object> l = new List<Object>();
foreach (DataColumn dc in firstcolumns) l.Add(dr[dc]);
if (Second.Rows.Find(l.ToArray()) == null) //NOT FOUND
{
table.Rows.Add(l.ToArray());
}
}
Cheers,

Compare dataset or a better idea

How do I compare values of one data set from another.
1st dataset ["proper records"] is coming from SQL Server with column names
[id], [subsNumber]
2nd dataset ["proper and inproper records"] is coming from progress database, with different columns except 1 which is subsNumber
How do I go and make another dataset which has all the [subsNumber] from ["proper records"] with matching records from 2nd datset ["proper inproper records"] ?
or
delete all the records in 2nd dataset["proper and inproper records"] which don't match the "subsNumber" column in the 1st dataset
or any other idea
basically How do I get all records from 2nd dataset which has same "subsNumber" as the 1st dataset

The key is using System.Data.DataRelation to join your 2 datatables on a common column (or columns).
Here's some code derived from a post at KC's See Sharp Blog
public DataTable GetImproperRecords(DataTable ProperRecords, DataTable ImproperRecords) {
DataTable relatedTable = new DataTable("Difference");
try {
using (DataSet dataSet = new DataSet()) {
dataSet.Tables.AddRange(new DataTable[] { ProperRecords.Copy(), ImproperRecords.Copy() });
DataColumn properColumn = new DataColumn();
properColumn = dataSet.Tables[0].Columns[1]; // Assuming subsNumber is at index 1
DataColumn improperColumn = new DataColumn();
improperColumn = dataSet.Tables[1].Columns[0]; // Assuming subsNumber is at index 0
//Create DataRelation
DataRelation relation = new DataRelation(string.Empty, properColumn, improperColumn, false);
dataSet.Relations.Add(relation);
//Create columns for return relatedTable
for (int i = 0; i < ImproperRecords.Columns.Count; i++) {
relatedTable.Columns.Add(ImproperRecords.Columns[i].ColumnName, ImproperRecords.Columns[i].DataType);
}
relatedTable.BeginLoadData();
foreach (DataRow parentrow in dataSet.Tables[1].Rows) {
DataRow[] childrows = parentrow.GetChildRows(relation);
if (childrows != null && childrows.Length > 0)
relatedTable.LoadDataRow(parentrow.ItemArray, true);
}
relatedTable.EndLoadData();
}
}
catch (Exception ex) {
Console.WriteLine(ex.Message);
}
return relatedTable;
}

I solved the problem:
1st dataset--> loop throuhg and get the subsNumber
Call function and pass subsNumber and 2nd dataset--> to it
Then start another loop for new dataset
Continue if subsnumber don't match
If subsNumber match work on that data like add columns to sqlserver table etc.
code:
foreach (DataRow row in ecommDS.Tables["EcommData"].Rows)
{
//string statCode = ""
string prdCode = ""; //declaring var for getting string format from ecomm
string checking = "";
prdCode = row["PRD-CDE"].ToString();
checking = row["SUBS-NUM"].ToString();
if(checking != subsNum)
{
continue;
}

To get all the records from 2nd dataset that match the records from the 1st dataset would be something like this:
IEnumerable list3 = list2.Where(l2=>list1.Contains(l1=>l1.subsNumber == l2.subsNumber));
Something along those lines!