Integer & Counter

Synopsis

There are several different data types for integers of different value ranges. Integers can be set, inserted, incremented, and decremented while COUNTER can only be incremented or decremented. We've extend Apache Cassandra to support increment and decrement operators for integer data types.

Syntax

The following keywords are used to specify a column of type integer for different constraints including its value ranges.

type_specification ::= TINYINT | SMALLINT | INT | INTEGER | BIGINT | VARINT | COUNTER

integer_literal ::= [ + | - ] digit [ { digit | , } ... ]

Semantics

• Columns of type TINYINT, SMALLINT, INT, INTEGER, BIGINT or VARINT can be part of the PRIMARY KEY.
• Values of different integer data types are comparable and convertible to one another.
• Values of integer data types are convertible but not comparable to floating point number.
• Values of floating point data types are not convertible to integers.

Counter data type

COUNTER is an alias of BIGINT but has additional constraints.

• Columns of type COUNTER cannot be part of thePRIMARY KEY.
• If a column is of type COUNTER, all non-primary-key columns must also be of type COUNTER.
• Column of type COUNTER cannot be set or inserted. They must be incremented or decremented.
• If a column of type COUNTER is NULL, its value is replaced with zero when incrementing or decrementing.

Examples

Using integer data types

cqlsh:example> CREATE TABLE items(id INT PRIMARY KEY, item_count BIGINT);

cqlsh:example> INSERT INTO items(id, item_count) VALUES(1, 1);

cqlsh:example> INSERT INTO items(id, item_count) VALUES(2, 2);

cqlsh:example> UPDATE items SET item_count = 5 WHERE id = 1;

cqlsh:example> UPDATE items SET item_count = item_count + 1 WHERE id = 2;

cqlsh:example> SELECT * FROM items;

 id | item_count
----+------------
  2 |          3
  1 |          5

Using COUNTER data type

cqlsh:example> CREATE TABLE item_counters(id INT PRIMARY KEY, item_counter COUNTER);

For counter type, null values are treated as 0.

cqlsh:example> UPDATE item_counters SET item_counter = item_counter + 1 WHERE id = 1;

cqlsh:example> SELECT * FROM item_counters;

 id | item_counter
----+--------------
  1 |            1

See also

Data Types