Search results
Results from the WOW.Com Content Network
Microsoft Access: A table named DUAL may be created and the single-row constraint enforced via ADO (Table-less UNION query in MS Access) Microsoft SQL Server: SQL Server does not require a dummy table. Queries like 'select 1 + 1' can be run without a "from" clause/table name. [5] MySQL allows DUAL to be specified as a table in queries that do ...
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. This can have major impact on performance because the correlated subquery might get recomputed every time for each row of the outer query is processed.
Creating complex queries using query-by-example (QBE) Searching globally in a database or a subset of it; Transforming stored data into any format using a set of predefined functions, like displaying BLOB-data as image or download-link; Live charts to monitor MySQL server activity like connections, processes, CPU/memory usage, etc.
The nested set model is a technique for representing nested set collections (also known as trees or hierarchies) in relational databases.. It is based on Nested Intervals, that "are immune to hierarchy reorganization problem, and allow answering ancestor path hierarchical queries algorithmically — without accessing the stored hierarchy relation".
MySQL (/ ˌ m aɪ ˌ ɛ s ˌ k juː ˈ ɛ l /) [5] is an open-source relational database management system (RDBMS). [5] [6] Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, [7] and "SQL", the acronym for Structured Query Language.
Many modern web servers can directly execute on-line scripting languages such as ASP, JSP, Perl, PHP and Ruby either by the web server itself or via extension modules (e.g. mod_perl or mod_php) to the webserver. For example, WebDNA includes its own embedded database system. Either form of scripting (i.e., CGI or direct execution) can be used to ...
As of 21 November 2024 (the day of PHP 8.4's release), PHP is used as the server-side programming language on 75.4% of websites where the language could be determined; PHP 7 is the most used version of the language with 49.1% of websites using PHP being on that version, while 37.9% use PHP 8, 12.9% use PHP 5 and 0.1% use PHP 4.
The many types of indexes share the common property that they reduce the need to examine every entry when running a query. In large databases, this can reduce query time/cost by orders of magnitude. The simplest form of index is a sorted list of values that can be searched using a binary search with an adjacent reference to the location of the ...