Search results
Results from the WOW.Com Content Network
Example of QBE query with joins, designed in Borland's Paradox database. Query by Example (QBE) is a database query language for relational databases.It was devised by Moshé M. Zloof at IBM Research during the mid-1970s, in parallel to the development of SQL. [1]
The two algorithms above do not return the same results in all cases primarily because of the difference between when the vowels are removed. The first algorithm is used by most programming languages and the second is used by SQL. For example, "Tymczak" yields "T522" in the first algorithm, but "T520" in the algorithm used by SQL.
SQL is a well known query language and data manipulation language for relational databases; XQuery is a query language for XML data sources; XPath is a declarative language for navigating XML documents; YQL is an SQL-like query language created by Yahoo! Search engine query languages, e.g., as used by Google [5] or Bing [6]
The mapping is done by defining classes that correspond to the tables in the database, and containing all or a subset of the columns in the table as data members. [13] The correspondence, along with other relational model attributes such as primary keys, are specified using LINQ to SQL-defined attributes. For example,
Microsoft SQL Server: SQL Server does not require a dummy table. Queries like 'select 1 + 1' can be run without a "from" clause/table name. [5] MySQL allows DUAL to be specified as a table in queries that do not need data from any tables. [6] It is suitable for use in selecting a result function such as SYSDATE() or USER(), although it is not ...
Title Authors ----- ----- SQL Examples and Guide 4 The Joy of SQL 1 An Introduction to SQL 2 Pitfalls of SQL 1 Under the precondition that isbn is the only common column name of the two tables and that a column named title only exists in the Book table, one could re-write the query above in the following form:
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 generator is very similar to a function that returns an array, in that a generator has parameters, can be called, and generates a sequence of values. However, instead of building an array containing all the values and returning them all at once, a generator yields the values one at a time, which requires less memory and allows the caller to ...