Learn Cassandra


1CQL consists of statements. Like SQL, statements change data, look up data, store data, or change the way data is stored. Statements end in a semicolon (;).

For example, the following is valid CQL syntax:


  SET SomeColumn = 'Some Value'
  WHERE columnName = 'Something Else';

This is a sequence of two CQL statements. This example shows one statement per line, although a statement can usefully be split across lines as well.

Uppercase and Lowercase

Keyspace, column, and table names created using CQL are case-insensitive unless enclosed in double quotation marks. If you enter names for these objects using any uppercase letters, Cassandra stores the names in lowercase. You can force the case by using double quotation marks.

For example:

  Foo int PRIMARY KEY,
  "Bar" int

CQL keywords are case-insensitive. For example, the keywords SELECT and select are equivalent.

CQL Data Types

2CQL defines built-in data types for columns:

CQL Type Constants Description
ascii strings US-ASCII character string
bigint integers 64-bit signed long
blob blobs Arbitrary bytes (no validation), expressed as hexadecimal
boolean booleans true or false
counter integers Distributed counter value (64-bit long)
decimal integers, floats Variable-precision decimal
double integers, floats 64-bit IEEE-754 floating point
float integers, floats 32-bit IEEE-754 floating point
inet strings IP address string in IPv4 or IPv6 format*
int integers 32-bit signed integer
list<T> n/a A collection of one or more ordered elements, T could be any non-collection CQL data type, such as int, text, etc
map<K,V> n/a A key-value dictionary, K and V could be any non-collection CQL data type, such as int, text, etc
set<T> n/a A collection of one or more elements, T could be any non-collection CQL data type, such as int, text, etc
text strings UTF-8 encoded string
timestamp integers, strings Date plus time, encoded as 8 bytes since epoch
uuid uuids A UUID in standard UUID format
timeuuid uuids Type 1 UUID only
varchar strings UTF-8 encoded string
varint integers Arbitrary-precision integer

CQL Command Reference

For a complete CQL command reference, see CQL commands.


  1. http://www.datastax.com/documentation/cql/3.1/cql/cql_reference/cql_lexicon_c.html
  2. http://www.datastax.com/documentation/cql/3.1/cql/cql_reference/cql_data_types_c.html