CQL native functions

Describes scalar functions that work on values in a single row of data to create a new value.

CQL supports several functions that transform a column value into a new value.

Tip: In addition, users can define functions and aggregates.

Scalar functions

The DataStax Enterprise database supports the following native functions.
cast
Converts the data returned by the selector to a native CQL data type.
CAST( selector AS to_type )
Cast strictly relies on the Java semantics, for more details on the underlying type see CQL types Java derivation.
Note: Silently ignores casting a column into its own data type.
Selector column type Output data type (to_type)
ascii text, varchar
bigint

tinyint, smallint, int, varint, float, double, decimal, text, varchar

boolean text, varchar
counter tinyint, smallint, int, bigint, float, double, decimal, varint, text, varchar
date timestamp
decimal tinyint, smallint, int, bigint, float, double, varint, text, varchar
double tinyint, smallint, int, bigint, float, decimal, varint, text, varchar
float tinyint, smallint, int, bigint, double, decimal, varint, text, varchar
inet text, varchar
int tinyint, smallint, bigint, float, double, decimal, varint, text, varchar
smallint tinyint, int, bigint, float, double, decimal, varint,text, varchar
time text, varchar
timestamp date, text, varchar
timeuuid timestamp, date, text, varchar
tinyint tinyint, smallint, int, bigint, float, double, decimal, varint, text, varchar
uuid text, varchar
varint tinyint, smallint, int, bigint, float, double, decimal, text, varchar
The Java types, from which most CQL types are derived, are obvious to Java programmers. The derivation of the following types, however, might not be obvious:
Table 1. CQL types Java derivation
CQL type Java type
decimal java.math.BigDecimal
float java.lang.Float
double java.lang.Double
varint java.math.BigInteger
token
Computes a token for values in the target column.
TOKEN(column_name)
The exact signature of the token function depends on the table concerned and of the partitioner used by the cluster.
  • Murmur3Partitioner type is bigint
  • RandomPartitioner type is varint
  • ByteOrderedPartitioner type is blob
Use in the following CQL requests:
  • SELECT selector clause to return values in the target column as tokens; useful for manually paging through the data or to determine the physical location of a row or set of rows.
  • SELECT where clause to return a set of records in a given token range. Allows comparison (greater than and less then) in the where clause without the use of ALLOW FILTERING. Useful when dividing query workloads between clients, such as multiple Spark clients for analytics.
Note: UPDATE does not support the token function in the where clause.
ttl
Count down in seconds until the value in the field expires and the data is automatically removed; null indicates that TTL for the column is not set (or the count down has ended).
TTL(column_name)
Use only in selectors clause of SELECT statements on non-partition key columns.
Warning: The database storage engine can only encode TTL timestamps through January 19 2038 03:14:07 UTC due to the Year 2038 problem. The TTL date overflow policy determines whether requests with expiration timestamps later than the maximum date are rejected or inserted. See -Dcassandra.expiration_date_overflow_policy.
uuid
Takes no parameters and generates a random type 4 uuid.
UUID()
Use to generate a value in INSERT and UPDATE.
Restriction: UPDATE statements SET clause cannot be used to change PRIMARY KEY fields; therefore a new UUID can only be set if the target field is not part of the PRIMARY KEY field.
writeTime
Shows the unix timestamp (number of seconds since epoch) that the data was written.
WRITETIME(column_name)
Use only in selectors clause of SELECT statements on non-partition key columns.

Date and time functions

Current date and time

Return the (current) system time of the coordinator node in a CQL type format. These functions have no arguments.

currentDate
Returns the system time in date format.
currentTime
Returns the system time in time format.
currentTimestamp
Returns the system time in timestamp format.
currentTimeUuid
Returns the system time in timeuuid format.
Restriction:
  • UPDATE statements SET clause cannot be used to change PRIMARY KEY fields; therefore a new timeuuid can only be set if the target field is not part of the PRIMARY KEY field.
  • Use in INSERT or UPDATE statements to generate a new timeuuid value.
  • Although allowed in WHERE clauses, no values would match a given SELECT or UPDATE statement because now() is guaranteed to be unique.
floor
Rounds date and time to the nearest value.
  • timestamp
    (timestamp, duration [, start_timestamp])
    If the start_timestamp is not used, then the start timestamp is January 1, 1970 00:00:00.000 GMT.
  • timeuuid
    floor(timeuuid, duration [, start_timestamp])
    If the start_timestamp is not used, then the start timestamp is January 1, 1970 00:00:00.000 GMT.
  • date
    floor(date, duration [, start_date])
    If the start_date is not used, then the start date is January 1, 1970 GMT.
  • time
    floor(time, duration[, start_time])
    If the start_time is not used, then the start time is 00:00:00[000000000].
Use the duration syntax as follows:
  • N y - Number of years
  • N mo - Number of months
  • N w - Number of weeks
  • N d - Number of days
  • N h - Number of hours
  • N m - Number of minutes
  • N s - Number of seconds
  • N ms - Number of milliseconds
  • N us or µs - Number of microseconds
  • N ns - Number of nanoseconds
now
Alias of currentTimeUuid.

TimeUuid calculations

minTimeUuid
Computes the smallest fake timeuuid from the specified date ('yyyy-mm-dd') or timestamp ('yyyy-mm-dd [hh:mm:ss[.fff][+/-NNNN]]') formatted string.
minTimeuuid( date_string | timestamp_string )

Use in a SELECT statement WHERE clause to return rows in a date range from a timeuuid column, for example WHERE id >= minTimeuuid('2017-05-01').

maxTimeUuid
Computes the largest fake timeuuid from the specified date ('yyyy-mm-dd') or timestamp ('yyyy-mm-dd [hh:mm:ss[.fff][+/-NNNN]]') formatted string.
MAXTIMEUUID( date_string | timestamp_string )

Use in a SELECT statement where clause to return rows in a date range from a timeuuid column, for example WHERE id <= maxTimeuuid('2017-05-01').

Date and time conversion

Converts the data in the defined argument from a timestamp, date, and timeuuid to another type.

toDate
Converts a timestamp value from milliseconds to days (since epoch) and for timeuuid extracts the timestamp and converts it to days since epoch.
TODATE(column_name)
Note: Dates and times display in string format, but are stored and compared as integers.
toTimestamp
Converts a date value from days into milliseconds since epoch and for timeuuid extracts the timestamp.
TOTIMESTAMP(column_name)
Note: Time (hh:mm:ss.ffffff+NNNN) of a date are all set to zero in the resulting timestamp.
toUnixTimestamp
Converts the timeuuid, timestamp, or date column into the number of seconds since epoch.
TOUNIXTIMESTAMP(column_name)

Blob conversion

Convert CQL native types to binary (blob).
blobAs
Converts the target column or literal (enclose strings in single quotes) from a blob to the specified type.
blobAstype(column_name | literal)
  • Display blob columns as another data type in results of SELECT statements.
  • Convert raw blob data into another type for storage INSERT and UPDATE.
AsBlob
Converts the target column or literal (enclose strings in single quotes) to a blob from the specified type, where the from type corresponds to a valid CQL data type.
typeAsBlob(column_name | literal )
Use in the following types of CQL statements:
  • SELECT selectors to return a value stored in another CQL type as a blob.
  • INSERT and UPDATE convert another CQL data type into a blob for storage.

Deprecated functions

The following functions are supported for backward compatibility only.

dateOf
Similar to toTimestamp.
unixTimestampOf
Similar to toUnixTimestamp