When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Data definition language - Wikipedia

    en.wikipedia.org/wiki/Data_definition_language

    The DROP statement destroys an existing database, table, index, or view. A DROP statement in SQL removes a component from a relational database management system (RDBMS). The types of objects that can be dropped depends on which RDBMS is being used, but most support the dropping of tables, users, and databases.

  3. SQL syntax - Wikipedia

    en.wikipedia.org/wiki/SQL_syntax

    SQL syntax. The syntax of the SQL programming language is defined and maintained by ISO/IEC SC 32 as part of ISO/IEC 9075. This standard is not freely available. Despite the existence of the standard, SQL code is not completely portable among different database systems without adjustments.

  4. Database index - Wikipedia

    en.wikipedia.org/wiki/Database_index

    Database index. A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time said table is accessed.

  5. Truncate (SQL) - Wikipedia

    en.wikipedia.org/wiki/Truncate_(SQL)

    In SQL, the TRUNCATE TABLE statement is a Data Manipulation Language (DML) operation that deletes all rows of a table without causing a triggered action. [1] The result of this operation quickly removes all data from a table, typically bypassing a number of integrity enforcing mechanisms. It was officially introduced in the SQL:2008 standard ...

  6. Drop - Wikipedia

    en.wikipedia.org/wiki/Drop

    Drop (SQL), a command in SQL queries to remove an existing database, table, index, or view; Drop (telecommunication), the portion of a device directly connected to the internal station facilities; Don't Route Or Peer (DROP) list, a list of spam sources; Drops (app), a language learning app

  7. Extract, transform, load - Wikipedia

    en.wikipedia.org/wiki/Extract,_transform,_load

    e. In computing, extract, transform, load (ETL) is a three-phase process where data is extracted from an input source, transformed (including cleaning), and loaded into an output data container. The data can be collated from one or more sources and it can also be output to one or more destinations. ETL processing is typically executed using ...

  8. SQL - Wikipedia

    en.wikipedia.org/wiki/SQL

    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 ...

  9. Data control language - Wikipedia

    en.wikipedia.org/wiki/Data_Control_Language

    In particular, it is a component of Structured Query Language (SQL). Data Control Language is one of the logical group in SQL Commands. SQL [1] is the standard language for relational database management systems. SQL statements are used to perform tasks such as insert data to a database, delete or update data in a database, or retrieve data ...