Develop Reference

Rearrange DB query result in array for duplicate rows

I want to rearrange query result from db with duplicate data into distinct row (for data display )but having 1 column collect related values in comma separated if more than 1 item found.
For example consider list below (from db query):
ID GROUP DATE
A1212 1 1/1/2019
A1212 2 1/1/2019
A1313 1 3/1/2019
into:
ID GROUP
A1212 1,2
A1313 1
sql string:
select DISTINCT Declaration_Form_Master.*,Declaration_Form_Detail.KPA_Group, Temp_Storage_Reg_V.*,Temp_Storage_Reg_V.ID as TSEID,Users.Company As Uc, 'NULL' as 'CTU_id' from Declaration_Form_Master left outer join Temp_Storage_Reg_V on (Declaration_Form_Master.Master_ID=Temp_Storage_Reg_V.TSEMaster_ID) right join Users on (Declaration_Form_Master.Agent_ID = Users.UserId) right join Declaration_Form_Detail on (Declaration_Form_Master.Master_ID = Declaration_Form_Detail.Master_ID) where Declaration_Form_Master.Confirmation ='1' and Submit_Date >= '2019-01-28' and Submit_Date < '2019-08-30' order by Application_ID DESC
need to join all table because search criteria based on column on multiple table. i cant figure out on sql, but want to rearrange back the result using array or list.
Maybe some algorithm can help.

Try following :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
DataTable dt = new DataTable();
dt.Columns.Add("ID", typeof(string));
dt.Columns.Add("GROUP", typeof(int));
dt.Columns.Add("DATE", typeof(DateTime));
dt.Rows.Add(new object[] {"A1212", 1, DateTime.Parse("1/1/2019")});
dt.Rows.Add(new object[] {"A1212", 2, DateTime.Parse("1/1/2019")});
dt.Rows.Add(new object[] {"A1213", 1, DateTime.Parse("3/1/2019")});
DataTable dt2 = new DataTable();
dt2.Columns.Add("ID", typeof(string));
dt2.Columns.Add("GROUP", typeof(string));
var groups = dt.AsEnumerable().GroupBy(x => x.Field<string>("ID")).ToList();
foreach (var group in groups)
{
dt2.Rows.Add(new object[] {
group.Key,
string.Join(",", group.Select(x => x.Field<int>("GROUP").ToString()).Distinct())
});
}
}
}
}

If you want to do this action even in T-SQL you must aggregate the result
By exemple
DECLARE #fakeTable TABLE (ID varchar(50), [GROUP] int)
INSERT INTO #fakeTable
VALUES
('A1212', 1 ),
('A1212', 2 ),
('A1213', 1 )
SELECT
ID,
[GROUP] = stuff((
SELECT ','+convert(varchar(100),[GROUP])
FROM #fakeTable innerTable
WHERE innerTable.ID = orgTable.ID
ORDER BY [GROUP]
for xml path (''), type).value('.','nvarchar(max)')
,1,1,'')
FROM (
SELECT DISTINCT ID FROM #fakeTable
) orgTable
More info about aggregation

DataTable dx = new DataTable();
dx.Columns.Add("Application_ID", typeof(int));
dx.Columns.Add("KPA_Group", typeof(int));
foreach(var z in data) {
dx.Rows.Add(new object[] { z.Application_ID,z.KPA_Group });
}
DataTable dt1 = new DataTable();
dt1.Columns.Add("Application_ID", typeof(string));
dt1.Columns.Add("KPA_Group", typeof(string));
var groups = dx.AsEnumerable().GroupBy(x => x.Field<Int32>("Application_ID")).ToList();
foreach (var group in groups)
{
dt1.Rows.Add(new object[] {
group.Key,
string.Join(",", group.Select(x => x.Field<int>("KPA_Group").ToString()).Distinct())
});
}
foreach (DataRow row in dt1.Rows)
{
#:#row["Application_ID"].ToString() |
#:#row["KPA_Group"] <br />
}
result :
2019080001 | 2,3
2019070002 | 2
2019070001 | 2
2019060001 | 1,2
2019040002 | 2
2019030002 | 2
2019030001 | 2
2019020002 | 2
2019020001 | 2
i dont understand why i can't use CopyToDataTable method. solved this by using foreach.

how to add two datatables dt1=2 column ,dt2=3 column, into one datatable dt3=5 column

how to add two datatables?
(dt1=name,phone_number)
and
(dt2=address,cityname)
Result:
(dt3=name,phone_number,address,cityname)

Ruben, you will need some primary key in order to combine both tables unless you are 100% sure that both data tables have the same number of rows and they will always be stored in the correct order.
There is a similar question answered and the link is: Combining n DataTables into a Single DataTable
Here goes the content of the provided link:
"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"
Source: Combining n DataTables into a Single DataTable
Last Access: 04-August-2016

First you can filter right column in to separate data datable
DataTable filterDatatable1= new DataTable();
DataTable filterDatatable2= new DataTable();
DataTable filterDatatable1= OriginaDatatable1.DefaultView.ToTable(false, "ColumnName1", "ColimnName2");
DataTable filterDatatable1= OriginaDatatable1.DefaultView.ToTable(false, "ColumnName1", "ColimnName2", "ColimnName3");
Then you can use merge function
DataTable dtAll = new DataTable();
dtAll.Merge(filterDatatable1);
dtAll.Merge(filterDatatable2);

compare and merge the datatable in C# [duplicate]

Let T1 and T2 are DataTables with following fields
T1(CustID, ColX, ColY)
T2(CustID, ColZ)
I need the joint table
TJ (CustID, ColX, ColY, ColZ)
How this can be done in C# code in a simple way? Thanks.

If you are allowed to use LINQ, take a look at the following example. It creates two DataTables with integer columns, fills them with some records, join them using LINQ query and outputs them to Console.
DataTable dt1 = new DataTable();
dt1.Columns.Add("CustID", typeof(int));
dt1.Columns.Add("ColX", typeof(int));
dt1.Columns.Add("ColY", typeof(int));
DataTable dt2 = new DataTable();
dt2.Columns.Add("CustID", typeof(int));
dt2.Columns.Add("ColZ", typeof(int));
for (int i = 1; i <= 5; i++)
{
DataRow row = dt1.NewRow();
row["CustID"] = i;
row["ColX"] = 10 + i;
row["ColY"] = 20 + i;
dt1.Rows.Add(row);
row = dt2.NewRow();
row["CustID"] = i;
row["ColZ"] = 30 + i;
dt2.Rows.Add(row);
}
var results = from table1 in dt1.AsEnumerable()
join table2 in dt2.AsEnumerable() on (int)table1["CustID"] equals (int)table2["CustID"]
select new
{
CustID = (int)table1["CustID"],
ColX = (int)table1["ColX"],
ColY = (int)table1["ColY"],
ColZ = (int)table2["ColZ"]
};
foreach (var item in results)
{
Console.WriteLine(String.Format("ID = {0}, ColX = {1}, ColY = {2}, ColZ = {3}", item.CustID, item.ColX, item.ColY, item.ColZ));
}
Console.ReadLine();
// Output:
// ID = 1, ColX = 11, ColY = 21, ColZ = 31
// ID = 2, ColX = 12, ColY = 22, ColZ = 32
// ID = 3, ColX = 13, ColY = 23, ColZ = 33
// ID = 4, ColX = 14, ColY = 24, ColZ = 34
// ID = 5, ColX = 15, ColY = 25, ColZ = 35

I wanted a function that would join tables without requiring you to define the columns using an anonymous type selector, but had a hard time finding any. I ended up having to make my own. Hopefully this will help anyone in the future who searches for this:
private DataTable JoinDataTables(DataTable t1, DataTable t2, params Func<DataRow, DataRow, bool>[] joinOn)
{
DataTable result = new DataTable();
foreach (DataColumn col in t1.Columns)
{
if (result.Columns[col.ColumnName] == null)
result.Columns.Add(col.ColumnName, col.DataType);
}
foreach (DataColumn col in t2.Columns)
{
if (result.Columns[col.ColumnName] == null)
result.Columns.Add(col.ColumnName, col.DataType);
}
foreach (DataRow row1 in t1.Rows)
{
var joinRows = t2.AsEnumerable().Where(row2 =>
{
foreach (var parameter in joinOn)
{
if (!parameter(row1, row2)) return false;
}
return true;
});
foreach (DataRow fromRow in joinRows)
{
DataRow insertRow = result.NewRow();
foreach (DataColumn col1 in t1.Columns)
{
insertRow[col1.ColumnName] = row1[col1.ColumnName];
}
foreach (DataColumn col2 in t2.Columns)
{
insertRow[col2.ColumnName] = fromRow[col2.ColumnName];
}
result.Rows.Add(insertRow);
}
}
return result;
}
An example of how you might use this:
var test = JoinDataTables(transactionInfo, transactionItems,
(row1, row2) =>
row1.Field<int>("TransactionID") == row2.Field<int>("TransactionID"));
One caveat: This is certainly not optimized, so be mindful when getting to row counts above 20k. If you know that one table will be larger than the other, try to put the smaller one first and the larger one second.

This is my code. Not perfect, but working good. I hope it helps somebody:
static System.Data.DataTable DtTbl (System.Data.DataTable[] dtToJoin)
{
System.Data.DataTable dtJoined = new System.Data.DataTable();
foreach (System.Data.DataColumn dc in dtToJoin[0].Columns)
dtJoined.Columns.Add(dc.ColumnName);
foreach (System.Data.DataTable dt in dtToJoin)
foreach (System.Data.DataRow dr1 in dt.Rows)
{
System.Data.DataRow dr = dtJoined.NewRow();
foreach (System.Data.DataColumn dc in dtToJoin[0].Columns)
dr[dc.ColumnName] = dr1[dc.ColumnName];
dtJoined.Rows.Add(dr);
}
return dtJoined;
}

this function will join 2 tables with a known join field, but this cannot allow 2 fields with the same name on both tables except the join field, a simple modification would be to save a dictionary with a counter and just add number to the same name filds.
public static DataTable JoinDataTable(DataTable dataTable1, DataTable dataTable2, string joinField)
{
var dt = new DataTable();
var joinTable = from t1 in dataTable1.AsEnumerable()
join t2 in dataTable2.AsEnumerable()
on t1[joinField] equals t2[joinField]
select new { t1, t2 };
foreach (DataColumn col in dataTable1.Columns)
dt.Columns.Add(col.ColumnName, typeof(string));
dt.Columns.Remove(joinField);
foreach (DataColumn col in dataTable2.Columns)
dt.Columns.Add(col.ColumnName, typeof(string));
foreach (var row in joinTable)
{
var newRow = dt.NewRow();
newRow.ItemArray = row.t1.ItemArray.Union(row.t2.ItemArray).ToArray();
dt.Rows.Add(newRow);
}
return dt;
}

I tried to do this in next way
public static DataTable JoinTwoTables(DataTable innerTable, DataTable outerTable)
{
DataTable resultTable = new DataTable();
var innerTableColumns = new List<string>();
foreach (DataColumn column in innerTable.Columns)
{
innerTableColumns.Add(column.ColumnName);
resultTable.Columns.Add(column.ColumnName);
}
var outerTableColumns = new List<string>();
foreach (DataColumn column in outerTable.Columns)
{
if (!innerTableColumns.Contains(column.ColumnName))
{
outerTableColumns.Add(column.ColumnName);
resultTable.Columns.Add(column.ColumnName);
}
}
for (int i = 0; i < innerTable.Rows.Count; i++)
{
var row = resultTable.NewRow();
innerTableColumns.ForEach(x =>
{
row[x] = innerTable.Rows[i][x];
});
outerTableColumns.ForEach(x =>
{
row[x] = outerTable.Rows[i][x];
});
resultTable.Rows.Add(row);
}
return resultTable;
}

Note that if you have a DataSet, you will need to steal the table from the Dataset with dataSet.Table[0]

Add columns of datatables in a dataset

I have a DataSet with 2 DataTable's. Each DataTable contains a column called "cost".
I want to calculate the sum of all costs for the 2 tables in a table called Result table, like the example below. How can I do that?
Table 1
Name | cost
balan | 6
gt | 5
Table 2
Name | cost
balan | 2
gt | 8
Result table
Name | cost
balan | 8
gt | 12

This is a way to do it:
DataTable dt1 = new DataTable();
DataTable dt2 = new DataTable();
DataTable results = new DataTable();
dt1.Columns.Add("Name");
dt1.Columns.Add("cost", typeof(int));
dt2.Columns.Add("Name");
dt2.Columns.Add("cost", typeof(int));
results.Columns.Add("Name");
results.Columns.Add("cost", typeof(int));
dt1.Rows.Add("balan", 6);
dt2.Rows.Add("balan", 2);
dt1.Rows.Add("gt", 5);
dt2.Rows.Add("gt", 8);
foreach (DataRow dr1 in dt1.Rows)
{
results.Rows
.Add(
dr1["Name"],
(int)dr1["cost"] + (int)dt2.Select(String.Format("Name='{0}'", dr1["name"]))[0]["cost"]
);
}

to get the result, you can do something like
var table1 = yourDataSet.Tables["Table 1"];
var table2 = yourDataSet.Tables["Table 2"];
var results = table1.AsEnumerable().Select(t1 => new {
name = t1.Field<string>("Name"),
cost = t1.Field<int>("cost")
})
.Concat(
table2.AsEnumerable().Select(t2 => new {
name = t2.Field<string>("Name"),
cost = t2.Field<int>("cost")
})
)
.GroupBy(m => m.name)
.Select(g => new {
name = g.Key,
cost = g.Sum(x => x.cost)
});
this won't give you a dataTable, but an IEnumerable. To transform an IEnumerable to a dataTable, see for example here
or easier, if table1 and table2 have same rows
var table1 = yourDataSet.Tables["Table 1"];
var table2 = yourDataSet.Tables["Table 2"];
var results = new DataTable();
results.Columns.Add("Name");
results.Columns.Add("cost", typeof(int));
table1.AsEnumerable().Concat(table2.AsEnumerable())
.GroupBy(m => m.Field<string>("Name"))
.Select(g => results.Rows.Add(g.Key, g.Sum(x => x.Field<int>("cost"))));

Save linq query as data table

In c# MVC, I need to get the following "result" (var) in the data table.
var allCompanies = objentity.ExecuteFunction<SearchAvailEmployees_Result>("SearchAvailEmployees", lstParam.ToArray())
.ToList();
var result = from c in allCompanies select new[] {
c.LastName,
c.FirstName,
c.Phone,
c.City,
c.PositionApplied,
c.Status,
Convert.ToString(c.CallDate.Value.ToShortDateString()),
Convert.ToString(c.CellOrPager),
c.Gender
};
I tried the following code but it won't works. It gives the error as
"Cannot implicitly convert type 'System.Collections.Generic.IEnumerable' to 'System.Collections.Generic.IEnumerable'. An explicit conversion exists (are you missing a cast?)"
IEnumerable<DataRow> query = from c in allCompanies select new[] {
c.LastName,
c.FirstName,
c.Phone,
c.City,
c.PositionApplied,
c.Status,
Convert.ToString(c.CallDate.Value.ToShortDateString()),
Convert.ToString(c.CellOrPager),
c.Gender
};
DataTable boundTable = query.CopyToDataTable<DataRow>();
Any alternate solution to save the linq query result in data table?

This is how I do it:
First I declare a new DataTable and add columns, in this :
DataTable dt = new DataTable();
dt.Columns.Add("FirstName");
dt.Columns.Add("LastName");
DataRow row = null;
Now I execute the desired query:
var query = from c in allCompanies select { c.LastName, c.FirstName};
Now I simply iterate through the query and fill a DataTable:
foreach (var rowObj in query)
{
row = dt.NewRow();
dt.Rows.Add(rowObj.FirstName, rowObj.LastName);
}
return dt;
Still in my queries I am using 'join'-statements.

First, create DataTable with correct schema:
var dataTable = new DataTable();
dataTable.Columns.Add("LastName", typeof (string));
dataTable.Columns.Add("FirstName", typeof(string));
// Add more columns
Second, select array of value object:
var result = allCompanies.Select(c => new object[] {
c.LastName,
c.FirstName,
c.Phone,
c.City,
c.PositionApplied,
c.Status,
Convert.ToString(c.CallDate.Value.ToShortDateString()),
Convert.ToString(c.CellOrPager),
c.Gender
}).ToList();
Third, loop to create new Row from DataTable and assign value to new Row:
result.Foreach(array => {
var row = dataTable.NewRow();
row.ItemArray = array;
dataTable.Rows.Add(row);
});

You should remove [] after new, it to be like
var result = from c in allCompanies
select new { c.LastName, c.FirstName, c.Phone, c.City,
c.PositionApplied, c.Status,
CallDate = Convert.ToString(c.CallDate.Value.ToShortDateString()),
CellOrPager = Convert.ToString(c.CellOrPager), c.Gender };
Create DataTable here
var dataTable = new DataTable();
dataTable.Columns.AddRange( new DataColumn[]{
new DataColumn("LastName" , typeof(string)),
new DataColumn("FirstName" , typeof(string)),
new DataColumn("Phone" , typeof(string)),
new DataColumn("City" , typeof(string)),
new DataColumn("PositionApplied" , typeof(string)),
new DataColumn("Status" , typeof(string)),
new DataColumn("CallDate" , typeof(string)),
new DataColumn("CellOrPager" , typeof(string)),
new DataColumn("Gender" , typeof(string))
});
Fill DataTable using this result
result.ToList().ForEach(x=>{
var row = dataTable.NewRow();
row.["LastName"] = x.LastName;
row.["FirstName"] = x.FirstName;
row.["Phone"] = x.Phone;
row.["City"] = x.City;
row.["PositionApplied"] = x.PositionApplied;
row.["Status"] = x.Status;
row.["CallDate"] = x.CallDate;
row.["CellOrPager"] = x.CellOrPager;
row.["Gender"] = x.Gender;
dataTable.Rows.Add(row);
});