Search results
Results From The WOW.Com Content Network
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".
Sometimes databases also support alternative syntax for this; for example, MySQL allows omitting the DEFAULT keyword, and T-SQL can use DEFAULT VALUES instead of VALUES(DEFAULT). The DEFAULT keyword can also be used in normal insertion to explicitly fill a column using that column's default value:
A more complex example: the expression a [/ html / @lang = 'en'][@href = 'help.php'][1]/ @target selects the value of the target attribute of the first a element among the children of the context node that has its href attribute set to help.php, provided the document's html top-level element also has a lang attribute set to en. The reference to ...
Certain jQuery object methods retrieve specific values (instead of modifying a state). An example of this is the val() method, which returns the current value of a text input element. In these cases, a statement such as $('#user-email').val() cannot be used for chaining as the return value does not reference a jQuery object.
Another key difference is the addressing of values. JSON has objects with a simple "key" to "value" mapping, whereas in XML addressing happens on "nodes", which all receive a unique ID via the XML processor. Additionally, the XML standard defines a common attribute xml:id, that can be used by the user, to set an ID explicitly.
If a call to such a component function is made inside a BEGIN - COMMIT bracket, nested transactions occur. Since popular databases like MySQL [1] do not allow nesting BEGIN - COMMIT brackets, a framework or a transaction monitor is needed to handle this. When we speak about nested transactions, it should be made clear that this feature is DBMS ...
MySQL (/ ˌ m aɪ ˌ ɛ s ˌ k juː ˈ ɛ l /) [6] is an open-source relational database management system (RDBMS). [6] [7] Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, [1] and "SQL", the acronym for Structured Query Language.
Users of Stack Overflow can earn reputation points and "badges"; for example, a person is awarded 10 reputation points for receiving an "up" vote on a question or an answer to a question, [12] and can receive badges for their valued contributions, [13] which represents a gamification of the traditional Q&A website. Users unlock new privileges ...