query


Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Acronyms, Wikipedia.
Related to query: Database query

query

[′kwir·ē]
(computer science)
A computer instruction to interrogate a data base.

query

(database, information science)
A user's (or agent's) request for information, generally as a formal request to a database or search engine.

SQL is the most common database query language.

query

(character)

query

To search for data. In addition to obtaining lists of records that match the search criteria, queries to a database allow for counting items and summing amounts. A query to a search engine such as Google or Bing yields a summary of the contents of Web pages and is more often called a "search."

For years, query and report programs have been the primary applications that produce output from information systems. A query implies an online request as required (look up that record), while a report implies a more elaborate printout with page headings and numbers that is typically produced at regular intervals such as end of month. See report writer.

Simple or Complex
Defining a query for a relational database can be extremely simple or very complex. If the query is based on one matching condition, such as "retrieve all customers who owe us more than $10,000," it is usually easy to define in a query language or program. However, "retrieve all customers who owe us more than $10,000 from purchasing toasters" is not easy. It requires several steps to determine how many toaster orders are in the balance due.

Tables Must Be Joined
Relational databases are designed to eliminate redundancy. The goal is to store a data item in one table and not have it duplicated in others. For example, an order record will contain the product number ordered, but often not its description. The description is stored in a product table. Thus, any printout of products ordered and their descriptions requires that the order table be linked to the product table for that query or report. Linking customer, order and product tables is a common example of "joining" tables to satisfy a query.

Contents of a Query
Most queries require at least the following conditions to be stated. First, which table or tables is the data coming from. If from two or more tables, what is the link between (typically account number or name). Next, define the selection criteria, which is the matching condition or filter. Lastly, define which fields in the tables are to be displayed or printed in the result. See SQL.


The Query Statement
This diagram depicts the typical conditions that have to be stated when querying a relational database.
References in classic literature ?
And then, as we drink, my opening query about roads and stopping-places on ahead.
This serious query was at first received with suspicion because it sounded like a conundrum.
Ye can't tell what'll be happenin'," Louis went on, in response to my query for more definite information.
As I writhed about I could see in his eyes that curiosity I had so often noted, that wonder and perplexity, that questing, that everlasting query of his as to what it was all about.
Create a query using the Copy of Direct Materials Budget table as the source.
The query cache stores the text of a SQL query statement (or stored procedure) together with the corresponding results that was sent to the client.
This approach assists query reformulation by recommending related queries.
Keywords: Self-organising map, Software retrieval, Query refinement, Thesaurus.
Then click on Data, Import External Data (exhibit 1, below) and select New Database Query.
Speed is a primary concern to security and compliance analysts; data loading and query running could consume vast amounts of time with such a volume of data.
DOC 1 Query is composed of three core components: Query Designer, Query Client md Query Web.
The research reported in this article is focused at the human-computer interaction and query level of Web user behavior.