All Products
Search
Document Center

PolarDB:COUNT

Last Updated:Jan 12, 2024

COUNT is a method that returns the number of elements in a collection.

The syntax for using COUNT is as follows:

collection.COUNT

collection is the name of a collection.

For a varray, COUNT always equals LAST.

The following example shows that an associative array can be sparsely populated (that is, the sequence of assigned elements has "gaps"). COUNT includes only the elements that have been assigned a value.

DECLARE
    TYPE sparse_arr_typ IS TABLE OF NUMBER INDEX BY BINARY_INTEGER;
    sparse_arr      sparse_arr_typ;
BEGIN
    sparse_arr(-100)  := -100;
    sparse_arr(-10)   := -10;
    sparse_arr(0)     := 0;
    sparse_arr(10)    := 10;
    sparse_arr(100)   := 100;
    DBMS_OUTPUT.PUT_LINE('COUNT: ' || sparse_arr.COUNT);
END;

The following output shows that COUNT includes five populated elements:

COUNT: 5