A query language is an artificially created programming language used to make queries in databases and information systems.
In general, such query methods can be classified depending on whether they serve for a database or for information retrieval. The difference is that requests to similar services are made to get actual answers to the questions posed, while the search engine tries to find documents containing information related to the area of ​​interest to the user.
Database
Database query languages ​​include the following examples:
- QL - object-oriented, refers to relational databases; successor to Datalog.
- (CQL) – - (, - ).
- CQLF (CODYASYL) – CODASYL-TYPE .
- - (COQL) – (com). construpt , - , .
- DMX – .
- Datalog – .
- Gellish English – , Gellish English ( ), .
- HTSQL – http- SQL.
- ISBL – PRTV ( ).
- LDAP – , TCP/IP.
- MDX – OLAP.
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Searching for the “incategory: Category” filter works on the basis of the initial issue of articles belonging to a specific group or list of pages. For example, a search query such as “Temples incategory: History” will return results on the history of temples. This function can also be used as advanced, setting various parameters.