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Query By Example
Query by Example (QBE) is a database query language for relational databases. History Query by Example was devised by Moshé M. Zloof at IBM Research during the mid-1970s, in parallel to the development of SQL, and influenced by the work on relational databases of Edgar Codd. It is the first graphical query language, using visual tables where the user would enter commands, example elements and conditions. Many graphical front-ends for databases use the ideas from QBE today. Originally limited only for the purpose of retrieving data, QBE was later extended to allow other operations, such as inserts, deletes and updates, as well as creation of temporary tables. The motivation behind QBE is that a parser can convert the user's actions into statements expressed in a database manipulation language, such as SQL. Behind the scenes, it is this statement that is actually executed. A suitably comprehensive front-end can minimize the burden on the user to remember the finer details of SQ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tableau Query
Tableau (French for 'little table' literally, also used to mean 'picture'; : tableaux or, rarely, tableaus) may refer to: Arts * ''Tableau'', a series of four paintings by Piet Mondrian titled ''Tableau I'' through to ''Tableau IV'' * ''Tableau vivant'', a motionless performance evoking a painting or sculpture; or a painting or photograph evoking such a theatrical scene * Scene (drama), in opera, ballet, and some other dramatic forms Games * Tableau (card game), a specific patience card game * Tableau (cards), the layout in patience and fishing card games * Tableau (dominoes), the layout in dominoes Other * Tableau, another term for a table of data, particularly: ** Cryptographic tableau, or tabula recta, used in manual cipher systems ** Division tableau, a table used to do long division * Method of analytic tableaux (also semantic tableau or truth tree), a technique of automated theorem proving in logic * Tableau Software, a company providing tools for data visualization and b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human–computer Interaction
Human–computer interaction (HCI) is the process through which people operate and engage with computer systems. Research in HCI covers the design and the use of computer technology, which focuses on the interfaces between people (users) and computers. HCI researchers observe the ways humans interact with computers and design technologies that allow humans to interact with computers in novel ways. These include visual, auditory, and tactile (haptic) feedback systems, which serve as channels for interaction in both traditional interfaces and mobile computing contexts. A device that allows interaction between human being and a computer is known as a "human–computer interface". As a field of research, human–computer interaction is situated at the intersection of computer science, behavioral sciences, design, media studies, and several other fields of study. The term was popularized by Stuart K. Card, Allen Newell, and Thomas P. Moran in their 1983 book, ''The Psychology of Hum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Query Languages
A query language, also known as data query language or database query language (DQL), is a computer language used to make queries in databases and information systems. In database systems, query languages rely on strict theory to retrieve information. A well known example is the Structured Query Language (SQL). Types Broadly, query languages can be classified according to whether they are ''database'' query languages or ''information retrieval'' query languages. The difference is that a database query language attempts to give factual answers to factual questions, while an information retrieval query language attempts to find documents containing information that is relevant to an area of inquiry. Other types of query languages include: * Full-text. The simplest query language is treating all terms as bag of words that are to be matched with the postings in the inverted index and where subsequently ranking models are applied to retrieve the most relevant documents. Only tokens ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relational Model
The relational model (RM) is an approach to managing data using a structure and language consistent with first-order predicate logic, first described in 1969 by English computer scientist Edgar F. Codd, where all data are represented in terms of tuples, grouped into relations. A database organized in terms of the relational model is a relational database. The purpose of the relational model is to provide a declarative method for specifying data and queries: users directly state what information the database contains and what information they want from it, and let the database management system software take care of describing data structures for storing the data and retrieval procedures for answering queries. Most relational databases use the SQL data definition and query language; these systems implement what can be regarded as an engineering approximation to the relational model. A '' table'' in a SQL database schema corresponds to a predicate variable; the contents of a tab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QBIC
Content-based image retrieval, also known as query by image content ( QBIC) and content-based visual information retrieval (CBVIR), is the application of computer vision techniques to the image retrieval problem, that is, the problem of searching for digital images in large databases (see this surveyContent-based Multimedia Information Retrieval: State of the Art and Challenges' (Original source, 404'''Content-based Multimedia Information Retrieval: State of the Art and Challenges'', Michael Lew, et al., ACM Transactions on Multimedia Computing, Communications, and Applications, pp. 1–19, 2006. for a scientific overview of the CBIR field). Content-based image retrieval is opposed to traditional concept-based approaches (see Concept-based image indexing). "Content-based" means that the search analyzes the contents of the image rather than the metadata such as keywords, tags, or descriptions associated with the image. The term "content" in this context might refer to colors, sha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GraphQL
GraphQL is a data query and manipulation language that allows specifying what data is to be retrieved (" declarative data fetching") or modified. A GraphQL server can process a client query using data from separate sources and present the results in a unified graph. The language is not tied to any specific database or storage engine. There are several open-source runtime engines for GraphQL. History Facebook started GraphQL development in 2012 and released a draft specification and reference implementation as open source in 2015. In 2018, GraphQL was moved to the newly established GraphQL Foundation, hosted by the non-profit Linux Foundation. On February 9, 2018, the GraphQL Schema Definition Language became part of the specification. Many popular public APIs adopted GraphQL as the default way to access them. These include public APIs of Facebook, GitHub, Yelp, Shopify, Google Directions API and many others. Design GraphQL supports reading, writing (mutating), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft Query By Example
Microsoft Query is a visual method of creating database queries using examples based on a text string, the name of a document or a list of documents. The QBE system converts the user input into a formal database query using Structured Query Language (SQL) on the backend, allowing the user to perform powerful searches without having to explicitly compose them in SQL, and without even needing to know SQL. It is derived from Moshé M. Zloof's original Query by Example (QBE) implemented in the mid-1970s at IBM's Research Centre in Yorktown, New York. In the context of Microsoft Access, QBE is used for introducing students to database querying, and as a user-friendly database management system for small businesses. Microsoft Excel allows results of QBE queries to be embedded in spreadsheets. See also *Query by Example *Microsoft Access *Microsoft SQL Server *Power Query Power Query is an ETL tool created by Microsoft for data extraction, loading and transformation, and is use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRUD
In computer programming, create, read, update, and delete (CRUD) are the four basic operations (actions) of persistent storage. CRUD is also sometimes used to describe user interface conventions that facilitate viewing, searching, and changing information using computer-based forms and reports. History The term ''C.R.U.D'' was likely first popularized in 1983 by James Martin in his book ''Managing the data-base environment''. Conceptual Data can be put in a ''location/area'' of a storage mechanism. * The fundamental feature of a storage location is that its ''content'' is both ''readable'' and ''updatable''. * Before a storage location can be read or updated it needs to be ''created''; that is allocated and initialized with content. * At some later point, the storage location may need to be ''destructed''; that is finalized and deallocated. Together these four operations make up the basic operations of storage management known as CRUD: ''Create'', ''Read'', ''Update'' and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SQL Injection
In computing, SQL injection is a code injection technique used to attack data-driven applications, in which malicious SQL statements are inserted into an entry field for execution (e.g. to dump the database contents to the attacker). SQL injection must exploit a security vulnerability in an application's software, for example, when user input is either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and unexpectedly executed. SQL injection is mostly known as an attack vector for websites but can be used to attack any type of SQL database. SQL injection attacks allow attackers to spoof identity, tamper with existing data, cause repudiation issues such as voiding transactions or changing balances, allow the complete disclosure of all data on the system, destroy the data or make it otherwise unavailable, and become administrators of the database server. Document-oriented NoSQL databases can also be affect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User Friendly
''User Friendly'' was a webcomic written by J. D. Frazer, also known by his pen name Illiad. Starting in 1997, the strip was one of the earliest webcomics to make its creator a living. The comic is set in a fictional internet service provider and draws humor from dealing with clueless users and geeky subjects. The comic ran seven days a week until 2009, when updates became sporadic, and since 2010 it had been in re-runs only. The webcomic was shut down in late February 2022, after an announcement from Frazer. Premise ''User Friendly'' is set inside a fictional ISP, Columbia Internet. According to reviewer Eric Burns, the strip is set in a world where "[u]sers were dumbasses who asked about cupholders that slid out of their computers, marketing executives were perverse and stupid and deserved humiliation, bosses were clueless and often naively cruel, and information technology, I.T. workers were somewhat shortsighted and misguided, but the last bastion of human reason... Every ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildcard Character
In software, a wildcard character is a kind of placeholder represented by a single character (computing), character, such as an asterisk (), which can be interpreted as a number of literal characters or an empty string. It is often used in file searches so the full name need not be typed. Telecommunication In telecommunications, a wildcard is a character that may be substituted for any of a defined subset of all possible characters. * In high-frequency (HF) radio automatic link establishment, the wildcard character may be substituted for any one of the 36 upper-case alphanumeric characters. * Whether the wildcard character represents a single character or a String (computer science), string of characters must be specified. Computing In computer (software) technology, a wildcard is a symbol used to replace or represent zero or more characters. Matching wildcards, Algorithms for matching wildcards have been developed in a number of recursion, recursive and non-recursive varietie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
