Tabular operators

This section explains how to use and combine tabular operators in APL.

The table summarizes the tabular operators available in APL.

Function	Description
count	Returns an integer representing the total number of records in the dataset.
distinct	Returns a dataset with unique values from the specified fields, removing any duplicate entries.
extend	Returns the original dataset with one or more new fields appended, based on the defined expressions.
extend-valid	Returns a table where the specified fields are extended with new values based on the given expression for valid rows.
limit	Returns the top N rows from the input dataset.
order	Returns the input dataset, sorted according to the specified fields and order.
parse	Returns the input dataset with new fields added based on the specified parsing pattern.
project	Returns a dataset containing only the specified fields.
project-away	Returns the input dataset excluding the specified fields.
project-keep	Returns a dataset with only the specified fields.
project-reorder	Returns a table with the specified fields reordered as requested followed by any unspecified fields in their original order.
sample	Returns a table containing the specified number of rows, selected randomly from the input dataset.
search	Returns all rows where the specified keyword appears in any field.
sort	Returns a table with rows ordered based on the specified fields.
summarize	Returns a table where each row represents a unique combination of values from the by fields, with the aggregated results calculated for the other fields.
take	Returns the specified number of rows from the dataset.
top	Returns the top N rows from the dataset based on the specified sorting criteria.
union	Returns all rows from the specified tables or queries.
where	Returns a filtered dataset containing only the rows where the condition evaluates to true.