Ad
related to: sql select and where clause function tutorial
Search results
Results From The WOW.Com Content Network
by adding a SQL window function to the SELECT-statement; ISO SQL:2008 introduced the FETCH FIRST clause. According to PostgreSQL v.9 documentation, an SQL window function "performs a calculation across a set of table rows that are somehow related to the current row", in a way similar to aggregate functions. [7]
SQL includes operators and functions for calculating values on stored values. SQL allows the use of expressions in the select list to project data, as in the following example, which returns a list of books that cost more than 100.00 with an additional sales_tax column containing a sales tax figure calculated at 6% of the price.
A WHERE clause in SQL specifies that a SQL Data Manipulation Language (DML) statement should only affect rows that meet specified criteria. The criteria are expressed in the form of predicates. WHERE clauses are not mandatory clauses of SQL DML statements, but can be used to limit the number of rows affected by a SQL DML statement or returned ...
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
In SQL these two categories are similar in their detailed syntax, data types, expressions etc., but distinct in their overall function. [ 3 ] The SQL-data change statements are a subset of the SQL-data statements; this also contains the SELECT query statement, [ 3 ] which strictly speaking is part of the DQL, not the DML.
A HAVING clause in SQL specifies that an SQL SELECT statement must only return rows where aggregate values ... SQL Aggregate Functions Archived May 3, 2017, at the ...
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!
An ORDER BY clause in SQL specifies that a SQL SELECT statement returns a result set with the rows being sorted by the values of one or more columns. The sort criteria does not have to be included in the result set (restrictions apply for SELECT DISTINCT, GROUP BY, UNION [DISTINCT], EXCEPT [DISTINCT] and INTERSECT [DISTINCT].)