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SQL refers to Structured Query Language, a kind of language used to access, update and manipulate database. In SQL, ROLLBACK is a command that causes all data changes since the last START TRANSACTION or BEGIN to be discarded by the relational database management systems (RDBMS), so that the state of the data is "rolled back" to the way it was before those changes were made.
It is a DML (Data Manipulation Language) command, therefore the following commands are used for this command: COMMIT and ROLLBACK; Deletes all or some records from the table, you can limit the records to be deleted by using the WHERE clause; Does not free the space occupied by the data in the table (in the TABLESPACE)
The alternative to autocommit mode (non-autocommit) means that the SQL client application itself is responsible for ending transactions explicitly via the commit or rollback SQL commands. [ 2 ] [ 3 ] Non-autocommit mode enables grouping of multiple data manipulation SQL commands into a single atomic transaction.
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 ...
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 ...
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.
TRANSACTION ROLLBACK; Database-level triggers can help enforce multi-table constraints, or emulate materialized views. If an exception is raised in a TRANSACTION COMMIT trigger, the changes made by the trigger so far are rolled back and the client application is notified, but the transaction remains active as if COMMIT had never been requested ...
Query by Example (QBE) is a database query language for relational databases. It was devised by Moshé M. Zloof at IBM Research during the mid-1970s, in parallel to the development of SQL . [ 1 ] It is the first graphical query language, using visual tables where the user would enter commands, example elements and conditions.