Search results
Results from the WOW.Com Content Network
Dataphor's D4 language is based on the principles of Christopher J Date's and Hugh Darwen's Tutorial D, but with a Pascal-like imperative syntax. Though Dataphor espouses to be truly relational, it does incorporate the concept of NULLs as found in SQL, which many claim to be contraindicated by the Relational Model. NULLs and the matter of ...
The relational algebra uses set union, set difference, and Cartesian product from set theory, and adds additional constraints to these operators to create new ones.. For set union and set difference, the two relations involved must be union-compatible—that is, the two relations must have the same set of attributes.
In computing, a materialized view is a database object that contains the results of a query.For example, it may be a local copy of data located remotely, or may be a subset of the rows and/or columns of a table or join result, or may be a summary using an aggregate function.
A common table expression, or CTE, (in SQL) is a temporary named result set, derived from a simple query and defined within the execution scope of a SELECT, INSERT, UPDATE, or DELETE statement. CTEs can be thought of as alternatives to derived tables ( subquery ), views , and inline user-defined functions.
The LINQ to SQL provider allows LINQ to be used to query Microsoft SQL Server databases, including SQL Server Compact databases. Since SQL Server data may reside on a remote server, and because SQL Server has its own query engine, LINQ to SQL does not use the query engine of LINQ. Instead, it converts a LINQ query to a SQL query that is then ...
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Pages for logged out editors learn more
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
A derived table is the use of referencing an SQL subquery in a FROM clause. Essentially, the derived table is a subquery that can be selected from or joined to. The derived table functionality allows the user to reference the subquery as a table. The derived table is sometimes referred to as an inline view or a subselect.