select distinct rows from datatable using linq c
Copying Rows from One DataTable to Another
Ngày tải lên :
28/10/2013, 18:15
... DataTable to copy DataRow objects from one
DataTable to another. Three techniques for selecting records to copy are demonstrated in
the following example:
ã
Use the Rows property to access rows in ... ConfigurationSettings.AppSettings["Sql_ConnectString"]);
DataTable dt = new DataTable( ORDERS_TABLE);
da.FillSchema(dt, SchemaType.Source);
da.Fill(dt);
// Clone the schema to the copy table.
DataTable dtCopy = dt.Clone( ... copy records from the source table to the
target table.
The C# code is shown in Example 5-1
.
Example 5-1. File: CopyRowsBetweenTablesForm.cs
// Namespaces, variables, and constants
using...
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Tài liệu Using Stored Procedures to Add, Modify, and Remove Rows from the Database phần 1 pdf
Ngày tải lên :
14/12/2013, 13:15
... SqlCommand object containing a SELECT
statement and sets the SelectCommand property of a SqlDataAdapter to that
SqlCommand:
SqlCommand mySelectCommand = mySqlConnection.CreateCommand();
mySelectCommand.CommandText ...
mySqlDataAdapter.SelectCommand = mySelectCommand;
The SELECT statement is then run when you call the mySqlDataAdapter object's Fill()
method to retrieve rows from the Products table into ... the Products table
UPDATE Products
SET
ProductName = @NewProductName,
UnitPrice = @NewUnitPrice
WHERE ProductID = @OldProductID
AND ProductName = @OldProductName
AND UnitPrice = @OldUnitPrice...
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Tài liệu Using Stored Procedures to Add, Modify, and Remove Rows from the Database phần 2 doc
Ngày tải lên :
14/12/2013, 13:15
... AddProduct4() stored procedure:
SqlCommand myInsertCommand = mySqlConnection.CreateCommand();
myInsertCommand.CommandText =
"EXECUTE @MyProductID = AddProduct4 @MyProductName, @MyUnitPrice"; ...
earlier in the SelectCommand property of mySqlDataAdapter:
SELECT ProductID, ProductName, UnitPrice
FROM Products
ORDER BY ProductID
To add a new row to a DataTable object, you use the same ... myUpdateCommand:
SqlCommand myUpdateCommand = mySqlConnection.CreateCommand();
myUpdateCommand.CommandText =
"EXECUTE UpdateProduct @OldProductID, @NewProductName, " +
"@NewUnitPrice, @OldProductName,...
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Using LINQ to DataSet
Ngày tải lên :
03/10/2013, 00:20
... disparate sources. You can mix LINQ to Objects and LINQ to DataSet
content in the same query simply by including each source in the From clause.
C#
// Build an ad hoc collection, although you could ...
a LINQ query.
Dwonloaded from: iDATA.ws
Chapter 18 Using LINQ to DataSet
313
Chapter 18 Quick Reference
To Do This
Include a DataTable instance in a LINQ query Call the DataTable object’s ... CurrentStatus = sts.Description
Order By OrderID
As in LINQ to Objects, the actual processing of a LINQ to DataSet query does not occur until
your code references content from a constructed query. However,...
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Using LINQ to Entities
Ngày tải lên :
03/10/2013, 00:20
... "A"
select cu;
Visual Basic
Dim result = From cu In context.Customers
Where EntityFunctions.Left(cu.FullName, 1) = "A"
Select cu
Beyond the canonical functions, LINQ to Entities ... CustomerName = cu.FullName };
}
Visual Basic
Using context As New SalesOrderEntities(connectionString)
Dim results = From cu In context.Customers
Order By cu.FullName
Select CustomerID = cu.ID, CustomerName ... string-conversion functions from SQL Server can
be called from LINQ: Ascii, Char, CharIndex, Difference (a Soundex-related function),
IsDate, IsNumeric, NChar, PatIndex, QuoteName, Replicate, SoundCode (more...
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Using LINQ to SQL
Ngày tải lên :
03/10/2013, 00:20
... Chapter 20 Using LINQ to SQL
335
C#
using (SalesOrderLink context = new SalesOrderLink(connectionString))
{
var results = from cu in context.Customers
orderby cu.FullName
select new { CustomerID ... CustomerID = cu.ID, CustomerName = cu.FullName };
}
Visual Basic
Using context As New SalesOrderLink(connectionString)
Dim results = From cu In context.Customers
Order By cu.FullName
Select CustomerID ... context.Customers
Select cu.ID, cu.FullName, context.AgedInvoices(cu.ID, 90)
Order By cu.FullName
You can also call these functions directly, as long as a valid context exists.
C#
decimal pending = context.AgedInvoices(whichCustomer,...
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Tài liệu Reading Rows from a SqlDataReader Object docx
Ngày tải lên :
21/01/2014, 07:20
... numeric positions of
a column
*/
using System;
using System.Data;
using System.Data.SqlClient;
class UsingColumnOrdinals
{
public static void Main()
{
SqlConnection mySqlConnection ... that Connection.
The following example closes productsSqlDataReader using the Close() method:
productsSqlDataReader.Close();
Once you've closed your DataReader, you can execute other commands ... the rows from your DataReader object, close it
using the Close() method. The reason for this is that a DataReader object ties up
the Connection object, and no other commands can be executed...
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Tài liệu Báo cáo khoa học: "Extracting Comparative Entities and Predicates from Texts Using Comparative Type Classification" pptx
Ngày tải lên :
20/02/2014, 04:20
... extracting comparative
sentences from text documents and an accuracy of
81.67% in classifying the comparative sentences
into seven comparative types.
The integrated results showed an accuracy ... results in comparative sentence
extraction (%)
As given above, we successfully detected CS-
candidates with considerably high recall by using
the comparison lexicon. We also successfully ... of Task 2 (Accuracy, %)
As shown above, we successfully extracted the
comparative entities and predicates with
outstanding performance, an overall accuracy of
86.81%.
6 Conclusions and...
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Tài liệu Báo cáo khoa học: "Knowledge Acquisition from Texts : Using an Automatic Clustering Method Based on Noun-Modifier Relationship" pptx
Ngày tải lên :
22/02/2014, 03:20
... object LINE; the PU
CONSTRUCTION OF THE LINE shows an action (CON-
STRUCTION) which can be applied to the object
LINE.
This definition of the context is original compared
to the classical context ... takes into account the
syntactical structure of the candidate terms. For in-
stance, LEXTER extracts the complex candidate term
BUILT DISPATCHING LINE, and analyses it in (BUILT
(DISPATCHING LINE)); ... we focus on NP
clustering. A NP is described by its "terminological
context". The four syntactic links of LEXTER Can be
used to define this terminological context. For in-
stance,...
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Báo cáo khoa học: "Deriving Generalized Knowledge from Corpora using WordNet Abstraction" pdf
Ngày tải lên :
24/03/2014, 03:20
... KNEXT logical form may arise from multiple
distinct syntactic constructs.
function SCORE (n ∈ N , α ∈ R
+
, C ⊆ W ⊆ W) :
C
← D(n) \ C
return
P
w C
L(w,n)
|C
|
α
function DERIVETYPES (W ⊆ W, ... of explicitly stated knowledge
in encyclopedias or similar sources. As well, such
sources typically do not cover the most obvious
facts of the world, such as that ice cream may be
delicious and ... Multidisciplinary Award
(2008).
815
word # gloss
abstraction 6 a general concept formed by extracting common features from speci c examples
attribute 2 an abstraction belonging to or characteristic...
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Using LINQ to SQL_1 potx
Ngày tải lên :
18/06/2014, 16:20
... một c u lệnh đơn (giúp dễ đ c hơn). Nó c ng cho phép bạn tạo ra
c c câu truy vấn từ c c câu kh c, giúp bạn c thể xây dựng c c câu truy vấn rất ph c tạp c ng như c
thể dùng lại đư c c c câu ... kết hợp đư c c c phép x c th c dữ liệu và c c quy t c chương trình (business logic). LINQ to
SQL c ng hỗ trợ nhiều c ch để c c nhà phát triển c thể dễ dàng tích hợp chúng vào với c c mô hình ...
cho vi c tích hợp c c lệnh LINQ to SQL vào c c đoạn mã truy c p dữ liệu đã c dễ dàng hơn. Nó
c ng c nghĩa là bạn c thể đưa c c c tài nguyên không phải c a CSDL vào trong c ng transaction....
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- 1
Using LINQ to SQL_2 pot
Ngày tải lên :
18/06/2014, 16:20
... về c ch dùng optimistic concurrency với LINQ to SQL trong c c bài viết kh c.
12. Dùng SPROCs ho c tùy biến logic c c câu SQL:
Một trong những c u hỏi mà c c nhà phát triển (và đ c biệt là c c ... áp dụng c c bộ l c LINQ c n thiết khi làm vi c với c c
lớp LINQ to SQL c a chúng ta để đảm bảo rằng chỉ c c c dữ liệu c n thiết đư c lấy về từ CSDL (ví
dụ: trong Grid ở trên, chỉ c 3 dùng ... c p vào danh sách này bằng
c ch gọi phương th c DataContext.GetChangeList(). Nó sẽ trả về một đối tượng ChangeList chứa
c c tập hợp cho c c thao t c thêm/xóa/sửa đã đư c th c hiện.
Một c ch...
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Using LINQ to SQL_3 pot
Ngày tải lên :
18/06/2014, 16:20
... bạn c ch viết lệnh để làm vi c với c c đối tượng trong mô hình dữ liệu, rồi cho phép
c c câu lệnh SQL động đư c th c thi? Sao tôi vẫn chưa cho c c bạn thấy c ch để gọi c c SPROC để
th c hiện ... c ng c thể dùng c c SPROCs trong CSDL trong lớp
DataContext, nó cung c p một c ch kh c để lấy về c c đối tượng Products bằng c ch gọi thủ t c
tương ứng:
LINQ to SQL Tutorial
74
C# : ... SPROC hay không. Ban đầu, bạn
c thể dùng c c câu SQL động đư c cung c p bởi LINQ to SQL cho tất c c c câu truy vấn, chèn,
c p nhật và xóa dữ liệu. Bạn sau đó c thể thêm vào c c quy t c để...
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Tài liệu Retrieve Results from SQL Server by Using the DataTable Object docx
Ngày tải lên :
26/01/2014, 11:20
... user clicks on the btnLoadList button, the data adapter called odaCust is
instantiated. The data adapter is passed strSQL and the connection string that is created
by the function called BuildCnnStr, ... set for the lstCustomers list box. This was all accomplished with a
Try-Catch-End-Try block of code.
Listing 3.3 frmHowTo3_2.vb: Loading a List Box By Using the DataTable
Object
Private Sub ... to be tracked.
1. To save time, you can make a copy of the form that was created in the first How-
To in this chapter.
2. Replace the btnLoadList Click event with the following code listed...
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