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A pivot table is a table of values which are aggregations of groups of individual values from a more extensive table (such as from a database, spreadsheet, or business intelligence program) within one or more discrete categories. The aggregations or summaries of the groups of the individual terms might include sums, averages, counts, or other ...
A Pseudocolumn is a "column" that yields a value when selected, but which is not an actual column of the table. An example is RowID or SysDate. [1] It is often used in combination with the DUAL table.
An SQL UPDATE statement changes the data of one or more records in a table. Either all the rows can be updated, or a subset may be chosen using a condition. The UPDATE statement has the following form: [1] UPDATE table_name SET column_name = value [, column_name = value ...] [WHERE condition]
In addition, it is relevant to consider that in-place changes, which overwrite old values without keeping any kind of history are discouraged. [1] There exist multiple approaches that keep track of the history of changes, such as timestamp -based solutions [ 5 ] or logging and locking .
As seen in the table above, direct equality comparisons between two NULLs in SQL (e.g. NULL = NULL) return a truth value of Unknown. This is in line with the interpretation that Null does not have a value (and is not a member of any data domain) but is rather a placeholder or "mark" for missing information.
In SQL, the data manipulation language comprises the SQL-data change statements, [3] which modify stored data but not the schema or database objects. Manipulation of persistent database objects, e.g., tables or stored procedures, via the SQL schema statements, [3] rather than the data stored within them, is considered to be part of a separate data definition language (DDL).
Time period definitions use two standard table columns as the start and end of a named time period, with closed set-open set semantics. This provides compatibility with existing data models, application code, and tools; Definition of application time period tables (elsewhere called valid time tables), using the PERIOD FOR annotation
Pito Salas is a Curaçaoan-American Cambridge, Massachusetts-based software developer.While working with Lotus ' Advanced Technology Group in 1986, Salas invented the pivot table, a "next-generation" spreadsheet concept that was released by Lotus in 1989, as Lotus Improv.