isdbnull in sql server

After a period of research, we started to optimize the performance this week. Before optimization, I will summarize some of the information I have investigated. 1. Background This is a system developed in the past 03 years. NET 1.1 + SQL Server 2000,

. NetAndSQL ServerMedium"Null Value"Discrimination   For beginner database programming, we may have some"Null Value"For example, all data in a new table is displayed, Manually add and delete text and then become blank; a string type field,

DBNull class Indicates a value that does not exist. This class cannot be inherited. Namespace: System Assembly: mscorlib (in mscorlib. dll) The DBNull class indicates a non-existent value. For example, in a database table, a column in a row may not

Http://info.shangdu.com/new/2003-5-8/200358113624.htm Visual Basic. NET is an upgraded version of Microsoft's Visual Basic language. It is a fully object-oriented programming language. Microsoft has made great improvements. ADO is no longer

1. null value addition. If null is added to other values (if varchar characters are used, the result is a null value. This is not expected in some composite character operations, so use the isnull function, if the value is null, a default value is

Several common creation methods are listed a few days ago. SQL Server Login , Login , User , System stored procedures used by roles and Groups , Of course, you also need to check Connectiongstring String SQL Server Login and database

asp.net| Design | Web page design 　　 This article takes the driving school management system as an example, describes how to use asp.net and SQL Server 2000来 to carry on the Dynamic Web page design, satisfies the user to the database real-time

DBNull class Represents a value that does not exist. This class cannot be inherited. Namespaces: System Assembly: mscorlib (in mscorlib.dll) The DBNull class represents a value that does not exist. For example, in a table in a database, a column

The DBNull class indicates a value that does not exist. This class cannot be inherited. Namespace: System Assembly: mscorlib (in mscorlib. dll) DBNull class indicates a non-existent value. For example, in a database table, a column in a row may not

SQL Anywhere. NET Support1. ADO is the latest data access API in Microsoft's ODBC, OLE DB, and ADO family. It is a Microsoft. NET Framework data access component that can be used to access a relational database system.2. The SQL Anywhere. NET Data