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In SQL, the data manipulation language comprises the SQL-data change statements, [3] which modify stored data but not the schema or database objects. Manipulation of persistent database objects, e.g., tables or stored procedures, via the SQL schema statements, [3] rather than the data stored within them, is considered to be part of a separate data definition language (DDL).
However, some extensions which use the PHP extension framework do not expose an API to the PHP developer. The PDO MySQL driver extension, for example, does not expose an API to the PHP developer, but provides an interface to the PDO layer above it. MySQLi is an improved version of the older PHP MySQL driver, offering various benefits. [3]
DQL statements are used for performing queries on the data within schema objects. The purpose of DQL commands is to get the schema relation based on the query passed to it. Although often considered part of DML, the SQL SELECT statement is strictly speaking an example of DQL. When adding FROM or WHERE data manipulators to the SELECT statement ...
The embedded SQL statements are parsed by an embedded SQL preprocessor and replaced by host-language calls to a code library. The output from the preprocessor is then compiled by the host compiler. This allows programmers to embed SQL statements in programs written in any number of languages such as C/C++, COBOL and Fortran.
NoSQL databases prioritize scalability along with supporting transactions in order to guarantee data consistency in the event of concurrent updates and accesses. In a database system, a transaction might consist of one or more data-manipulation statements and queries, each reading and/or writing information in the database.
PHP and MySQL Programming/Print version - Wikibooks, open books for an open world; Author: hbossot: Image title: File change date and time: 22:12, 9 September 2016: Date and time of digitizing: 22:12, 9 September 2016: Software used: PDFCreator 2.2.2.0: Conversion program: PDFCreator 2.2.2.0: Encrypted: no: Page size: 595 x 842 pts (A4) Version ...
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.
Limited support for triggers in the MySQL/MariaDB DBMS was added in the 5.0 version of MySQL, launched in 2005. [4] As of version 8.0, they allow for DDL (Data Definition Language) triggers and for DML (Data Manipulation Language) triggers. They also allow either type of DDL trigger (AFTER or BEFORE) to be used to define triggers.