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  2. Database trigger - Wikipedia

    en.wikipedia.org/wiki/Database_trigger

    Database trigger. A database trigger is procedural code that is automatically executed in response to certain events on a particular table or view in a database. The trigger is mostly used for maintaining the integrity of the information on the database. For example, when a new record (representing a new worker) is added to the employees table ...

  3. Merge (SQL) - Wikipedia

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

    Merge (SQL) A relational database management system uses SQL MERGE (also called upsert) statements to INSERT new records or UPDATE existing records depending on whether condition matches. It was officially introduced in the SQL:2003 standard, and expanded [citation needed] in the SQL:2008 standard.

  4. 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 ...

  5. Microsoft SQL Server - Wikipedia

    en.wikipedia.org/wiki/Microsoft_SQL_Server

    Microsoft SQL Server (Structured Query Language) is a proprietary relational database management system developed by Microsoft.As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications—which may run either on the same computer or on another computer across a network (including the Internet).

  6. SQL - Wikipedia

    en.wikipedia.org/wiki/SQL

    Structured Query Language ( SQL) ( pronouncedS-Q-L; historically "sequel") [4] [5] is a domain-specific language used to manage data, especially in a relational database management system (RDBMS). It is particularly useful in handling structured data, i.e., data incorporating relations among entities and variables.

  7. Correlated subquery - Wikipedia

    en.wikipedia.org/wiki/Correlated_subquery

    Correlated subquery. Appearance. hide. In a SQL database query, a correlated subquery (also known as a synchronized subquery) is a subquery (a query nested inside another query) that uses values from the outer query. Because the subquery may be evaluated once for each row processed by the outer query, it can be slow.

  8. Referential integrity - Wikipedia

    en.wikipedia.org/wiki/Referential_integrity

    Referential integrity is a property of data stating that all its references are valid. In the context of relational databases, it requires that if a value of one attribute (column) of a relation (table) references a value of another attribute (either in the same or a different relation), then the referenced value must exist. [1]

  9. Delete (SQL) - Wikipedia

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

    Delete (SQL) In the database structured query language ( SQL ), the DELETE statement is used to remove one or more records from a table. A subset may be defined for deletion using a condition, otherwise all records are removed. [1] Some database management systems (DBMSs), like MySQL, allow deletion of rows from multiple tables with one DELETE ...