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Access | data u other
Øasta
Often under the Delphi Network database application development or once used Borland Midas technology friend, to Asta should not unfamiliar.
If it is based on ado.net or O/R mapping to achieve the DAL is Shaolin, Wudang authentic method, that Asta has a point to teach the "big move" flavor: The entire DAL in the data
In many cases, we need to use a double loop to display the content.
For example, if you need to display partitions cyclically and the sections in the partition, the previous practice is
Obtain the partition set based on the partition ID on the page.
.
This destroys the organization of the business logic layer, presentation layer, and
;
}
}
Do you see some clues from the code above?
Because the web appliction Cache (httpcontext.current!= NULL to determine whether the Web Applicationj) is directly supported by the. NET framework, it is convenient to judge whether or not to expire. There is no thread-safe problem, J. But this problem for Windows
block in your. NET applications, reducing the number of custom code you need to create, test, and maintain from the page.
In particular, Data Access Application Block can help you:
Invokes a stored procedure or SQL text command. Specifies the parameter details. Returns a SqlDataReader, DataSet, or XmlReader object. For example, in an application that reference
The Spring framework uses the jdbcTemplate operation on the dao layer to delete data in crud, and jdbctemplatecrud
Use jdbcTemplate
The principle is to load the Driver Class. forName ("com. mysql. jdbc. Driver ");
And Connection conn = DriverManager. getConnection ("jdbc: mysql: // localhost: 3306/sw_database? User = root password = root ");
Use an object to com
The formatting of the incoming parameters of the 1.web access layer and the parameter formatting of the outgoing data of the Web return value should be unified.Like in Acspace,The incoming layer parameter @requestbody the JavaBean object. Unified conversion to JavaBean incoming parameters.Returns a value that returns t
describe getstring (1), getlong (2), and getint (15), the performance will be greatly improved.3.5. Search automatically generated keys
Many databases have hidden columns (also known as pseudo columns) that describe the unique keys in each row of the table ). Generally, because the pseudo column describes the physical disk address of the data, using this type of column access row in the query is the fastes
Access to | data 6. ASPECT
AOP (Aspect oriented programming) may have been unearthed in recent years
One of the most powerful technologies to come, the author does not intend to spend any time here to introduce it (online information has been a dime), just want to borrow its aspect concept to illustrate several design data
There are several types of database operations at the data access layer: concatenated strings, basic SQL statements with construction parameters, stored procedures, views, and so on. Because this system is mainly used to promote our learning, I tried these methods in this IDC charging system.
For example:
A. When quer
Direction
Gets or sets a value that indicates whether the parameter is input-only, output-only, or bidirectional stored procedure return-value parameters
Isnulllable
Gets or sets a value that indicates whether the parameter receives a null value
ParameterName
Gets or sets the name of the SqlParameter
Size
Gets or sets the maximum value of the data in the column
Designing and implementing a versatile data access tier for a asp.net application
by Paul Abarham
In this article, we'll drill down deeper the "a n-tier architecture and our focus'll be" on the data ACC ESS Tier (DAT)
Abstract
Design and implement a general-purpose data access
Data access layer (Development Process implementation code)
Posted By vasair at 11:18:00
In application design, database access is very important. We usually need to centralize database access to ensure good encapsulation and maintainability. In. for SQL Server
Therefore, it is best to use the Stored Procedure for paging at the data access layer. the following uses the employee table in the pubs database as an example to store data paging. You can refer to it to create your own stored procedure based on your actual situation.Note:
, the object will remain in scope after control leaves the using block, even if it may no longer have access to its unmanaged resources. In other words, the object can no longer be fully initialized. If you attempt to use the object outside the using block, you may cause an exception to be thrown, such as Font2 in code snippet 3 above. GetHeight () is called and an exception is generated. For this reason, it is usually better to instantiate the object
This article explains how to execute a single or batch stored procedure from the application layer (mainly calling the stored procedure that does not return any result set, but also extending it to calling the stored procedure that has returned results set ).
Data access layer:
This
the matching
To avoid this problem by commenting out the relevant content in the message, but once online,
can only be solved by other means!
Here, the author first tries to give 3 solutions:
I. For Web application, you can use the dependency mechanism provided by the. NET framework to bind cache to a file system, and once the data changes, you need to update the relevant file or directory informati
Therefore, it is best to use the Stored Procedure for paging at the data access layer. the following uses the employee table in the pubs database as an example to store data paging. You can refer to it to create your own stored procedure based on your actual situation.
N
reading the code, certain friends will have the question:
The RemoteCustomer in code 13 is the one we analyzed earlier.
The work that Data Access logic can accomplish, although it is separated by a layer of remoting,
But essentially the same, can not be with the code 11,12 in the Customerdal_orm
An "effective reorganization"?
The answer is YES!
However,
access | data u/r Mapping
The full name of the O/R Mapping is: Object Relational Mapping, the main purpose is to build a mapping relationship between the traditional RDBMS and OO language, thus leaving the developer completely disconnected from the data.
About O/R Mapping or recent popular o/x Mapping (you can refer to "programmer, 2004.01,p86"), may need speci
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