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[1] [2] The interface of an object conforming to this pattern would include functions such as Insert, Update, and Delete, plus properties that correspond more or less directly to the columns in the underlying database table. The active record pattern is an approach to accessing data in a database. A database table or view is wrapped into a class.
A range query is a common database operation that retrieves all records where some value is between an upper and lower boundary. [1] For example, list all employees with 3 to 5 years' experience. Range queries are unusual because it is not generally known in advance how many entries a range query will return, or if it will return any at all.
For one-dimensional arrays, this facility may be provided as an operation append(A,x) that increases the size of the array A by one and then sets the value of the last element to x. Other array types (such as Pascal strings) provide a concatenation operator, which can be used together with slicing to achieve that effect and more.
Following Lisp, other high-level programming languages which feature linked lists as primitive data structures have adopted an append. To append lists, as an operator, Haskell uses ++, OCaml uses @. Other languages use the + or ++ symbols to nondestructively concatenate a string, list, or array.
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 ...
Comma-separated values (CSV) is a text file format that uses commas to separate values, and newlines to separate records. A CSV file stores tabular data (numbers and text) in plain text, where each line of the file typically represents one data record.
Many data structures and databases implement immutable objects, effectively making their data structures append-only. Implementing an append-only data structure has many benefits, such as ensuring data consistency, improving performance, [6] and permitting rollbacks. [7] [8] The prototypical append-only data structure is the log file.
In computer science, an associative array, map, symbol table, or dictionary is an abstract data type that stores a collection of (key, value) pairs, such that each possible key appears at most once in the collection. In mathematical terms, an associative array is a function with finite domain. [1] It supports 'lookup', 'remove', and 'insert ...