What is a set of results?

The database results set is a table containing the selected line block from the database. Includes information stored in these lines along with "meta-information" for these lines. The meta-information contains details of the arrangement of rows, such as the total number of columns and the names of individual columns. The end user usually uses sets of results to create information in response to a request, which is a structured request from the database.

When the end user does a question, it requires specific information from the database. A sample question could try to create a list of names of all employees hired in the previous year. After interviewing, the database would search its content, found files that correspond to the required criteria, and place these files in a set of results. The results set is then displayed on the screen together with a meta-date. The "Order by" command in the structured language language (SQL) is dealing with this conflict, allowing the end user to dictate how it should databasePC program View results. For example, the organization through the alphabet is common. In the previous example, the results may be arranged by the hiring date.

Some meta-data may not be available, depending on the specific database program used. For example, the database request to pre -calculate the number of lines in a set of results, often turns out to be impossible because this information is not available in advance. Therefore, the application would ask the database for the exact number of employees over 25 years of age who earn $ 10,000 in USD (USD) per year or more - in other words, the number of lines that would be set for a question - could return the zero result because the program cannot know. Knowledge of this information may be necessary if the end user wishes to have a coacht of the result, but does not require a complete set of results; In other words, where the names of employees and other information are irrelevant or irrelevant for the request.