Object Name is Not Declared

Error BC30451: Object_name is not declared

An object, e.g. button, linkbutton, or lable is created on the .aspx page. The intellisense does detect the object name. However, when it is debugged, it gives the error Object_name is not declared, where Object_name is the name of the object.

Solution:
1. If you are web application project, try deleting the aspx.cs or aspx.vb (code) file, then right-click the .aspx file, and choose Convert to web application.

2. Check if there is another copy of the same files in the same folder. This happens to me quite some times. Before doing major changes, I usually make a copy of the files first. The files are usually automatically included in the solution we are developing. Since the class of the copies have the same names, they conflict each other. Move the copy from the folder or simply exclude the copies from the solution by right-clicking on the files, then choose "Exclude From Project". See if it solves the issue.

3. If neither solution 1 nor 2 solves the issue, try adding new files with different names, then copy the content of the old files to the new ones. Note that the names of the class can not be the same. Try compiling and see if it works. If it does, you can then delete or move the old files, then rename the new files according to the old ones.

4. If none of the alternatives above work, try finding from internet, then POST IT HERE! Thanks ^_^

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Paging in SQL 2

Regarding my post about Paging in SQL, I have found another easier way to include a column as a running number of the records. Hence, we do not need to create a temporary table, and the code will be much simpler.

I will use the same tables for example. In case you find difficulty finding the post about Paging in SQL, I include them here.

Here is the Create table Query:

CREATE TABLE dbo.MsUser
(  UserID CHAR(20) PRIMARY KEY,
   Username VARCHAR(100),
   Address VARCHAR(50),
   DivisionID INT
)

And here is the query to insert sample data:

-- Insert Data into MsUser
INSERT INTO dbo.MsUser VALUES ( 'Himura', 'Miss Himura', 'Earth', 3 )
INSERT INTO dbo.MsUser VALUES ( 'Selvia', 'Selvia', 'Indonesia', 2 )
INSERT INTO dbo.MsUser VALUES ( 'Superman', 'Clark Kent', 'Earth', 2 )
INSERT INTO dbo.MsUser VALUES ( 'SelviaHimura', 'Selvia Himura', 'Earth', 4 )
INSERT INTO dbo.MsUser VALUES ( 'Luck', 'Steven Luck', 'Indonesia', 1 )
INSERT INTO dbo.MsUser VALUES ( 'SuperLuck', 'Super Luck', 'United States', 1 )
INSERT INTO dbo.MsUser VALUES ( 'Selvi', 'Selvi', 'Indonesia', 1 )
INSERT INTO dbo.MsUser VALUES ( 'Lucky', 'Lucky Luke', 'United States', 3 )
INSERT INTO dbo.MsUser VALUES ( 'Steven', 'Steven', 'Earth', 4 )

Here is the data inserted to the tables:

Here is the query to get the data using paging:

DECLARE @PageSize INT, @PageNo INT
SELECT a.Username FROM (
    SELECT Username, RowNumber = ROW_NUMBER() OVER (ORDER BY Username) 
    FROM MsUser
) a WHERE a.RowNumber BETWEEN (@PageNo - 1 )* @PageSize + 1 AND @PageNo * @PageSize

Note that the key is in this part of code:

ROW_NUMBER() OVER (ORDER BY Username)

If the PageSize is set to 5 item per page, then the top 5 users will be displayed on Page 1 and the next 5 users will be displayed on Page 2.

e.g. 1

PageSize = 5, PageNo = 1

DECLARE @PageSize INT, @PageNo INT
SELECT  @PageSize = 5, @PageNo = 1
SELECT a.Username FROM (
    SELECT Username, RowNumber = ROW_NUMBER() OVER (ORDER BY Username) 
    FROM MsUser
) a WHERE a.RowNumber BETWEEN (@PageNo - 1 )* @PageSize + 1 AND @PageNo * @PageSize

The data retrieved on Page 1 will be:

e.g. 2

PageSize = 5, PageNo = 2

DECLARE @PageSize INT, @PageNo INT
SELECT  @PageSize = 5, @PageNo = 2
SELECT a.Username FROM (
    SELECT Username, RowNumber = ROW_NUMBER() OVER (ORDER BY Username) 
    FROM MsUser
) a WHERE a.RowNumber BETWEEN (@PageNo - 1 )* @PageSize + 1 AND @PageNo * @PageSize

And the data retrieved on Page 2 will be:

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