Querying

A database would not be any use unless we could search for the data we want. Searching is the process of looking through a database in order to retrieve data. In a database the way we search for data is to do a query.

 

A query is a search of a database based on a specific criteria. The query will be based on SQL, which stands for structured query language.

A query is constructed by telling the database which fields to look in, operator , data 

 

Query By Example:

Query-by-example  is the most common  form of creating a query. Looking at figure 5 below you can see that the criteria “red” is entered against the field “Tparts”. If the search requires searching two or more entities it is called a relational search.

 

More On Distributed Databases: Distributed Databases,

 

 

Related Topics (Information Systems) : DBMS, The 5 Types of Information Systems, Expert Systems, TPS, DSS, ES, MIS, OAS, Characteristics, computerised methods, non-computerised methods, flat file databases, relational databases, data modelling, URLs, storyboards, searching, HTML, backups, security methods, encryption, firewalls, virus' and virus scanners, passwords and security levels, social and ethical issues, data accuracy, data integrity, data validation, data bias, data reliability, privacy, ownership and control of data, access to data, data warehousing, data mining, freedom of information, acknowledgement of data sources, issues related to new trends, sequential access, direct access, distributed databases, storage media, querying, operators, wildcards, sorting, SQL, biometrics and ethical issues, face recognition

 

See Also: Knowledge Management, data mining,Information systems