Functions

The table below contains the list of all supported Lenses SQL for streaming functions.

Name Description Usage
ANONYMIZE
Obfuscates the data, in order to protect it. If the anonymized
value is not provided it will use * for String and 0 for Numbers
anonymize(expression [,Anonymized value])
CAST Enables conversion of values from one data type to another cast(dt as int)
COALESCE
Returns the first non-null expression in the expression list.
You must specify two expressions
coalesce(value, prevValue)
CONCATENATE
Returns the string representation of concatenating each expression
in the list. Null fields are left out
concatenate(weather.main, 'fixed', dt,temp.eve)
LEN
Returns the length of a string. LEN calculates length
using characters as defined by UTF-16
len(name)
POSITION Return the position of the first occurrence of substring position('math' in fieldA)
REPLACE
Returns string with every occurrence of search_string
replaced with replacement_string
replace(fieldA, 'math', 'mathematics')
SUBSTRING Return a portion of the string, beginning at the given position substring(field, 2)
TRIM Removes leading and trailing spaces trim(field)
LOWER Returns the argument in lowercase lower(name)
UPPER Returns the argument in uppercase upper(name)
UUID Returns an universally unique identifier uuid()
ABS
Returns the absolute value of an expression
it has to evaluate to a number type
abs(field1 + field2)
CEIL
Returns the absolute value of an expression
it has to evaluate to a number type
ceil(field1)
FLOOR Return the largest value not greater than the argument floor(field1)
‘%’
The remainder operator (%) computes the remainder after
dividing its first operand by its second. Each expression has
to evaluate to a number
a % b
‘/’
Divides one number by another (an arithmetic operator)
Each expression has to evaluate to a number
a / b
‘-‘
Subtracts one number from another (an arithmetic operator)
Each expression has to evaluate to a number
a - b
‘*’
Multiplies one number from another (an arithmetic operator)
Each expression has to evaluate to a number
a * b
‘+’
Adds one number to another (an arithmetic operator)
Each expression has to evaluate to a number
a + b
‘-‘ (negative)
Returns the negative of the value of a numeric expression
(a unary operator). The expression has to evaluate to a number
+a: if a<0, -a: if a>0
POW
Returns expression1 raised to the expression2 power.
Each expression has to evaluate to a number
pow(a, b)
SQRT
Returns the square root of expression.
The expression has to evaluate to a number
sqrt(a)
COUNT
Returns the number of records read
ONLY FOR STREAMING when grouping is involved
SELECT count(*)
MAX
Returns maximum value of expression.
ONLY FOR STREAMING when grouping is involved
max(field1)
MIN
Returns minimum value of expression.
ONLY FOR STREAMING when grouping is involved
min(field1)
SUM
Returns the sum of expression for each record read.
ONLY FOR STREAMING when grouping is involved
sum(field1)
IF
Evaluates the boolean result for condition. If true it will
return the value of expr1; otherwise, it evaluates and
returns the value of expr2
if(condition, expr1,expr2)
LPAD
Prepends the value of padExpr to the value of strExpr
until the total length is lengthExpr
LPAD(strExpr, lengthExpr, padExpr)
RPAD
Appends the value of padExpr to the value of strExpr
until the total length is lengthExpr
LPAD(strExpr, lengthExpr, padExpr)
EPOCH_TO_DATETIME
Converts an epoch into a datetime yyyy-MM-dd'T'HH:mm:ss.SSSZ
strExpr needs to be a LONG value containing the
milliseconds since 1 January 1970 00:00:00)
EPOCH_TO_DATETIME(strExpr)
EPOCH_TO_DATE
Converts an epoch into a date yyyy-MM-dd
The strExpr needs to resolve to INT/LONG value. If the
value is an INT it is expected to be the day represented
as days since epoch
EPOCH_TO_DATE(strExpr)
DATETIME_TO_EPOCH
Converts a string representation of a datetime into epoch value.
For AVRO records the new field will be of type Long with the
Timestamp logical type attached and the epoch value.
For JSON records the epoch will be expressed as LONG.
The first parameter strExpr needs to be a STRING value.
The second parameter pattern must be a DateTime Format
DATETIME_TO_EPOCH(strExpr, pattern)
DATE_TO_EPOCH
Converts a string representation of a date into epoch value.
For AVRO records, this will emit a field with a logical type of
Date. This means the output value is an INT and it represents
the days since Epoch. For JSON records the resulted value is the
epoch expressed as LONG. The first parameter strExpr needs to
resolve to a STRING value. The second parameter pattern,
must be a Date Format
DATE_TO_EPOCH(strExpr, pattern)
CONVERT_TIME
Converts the string format of a date [and time]. The first
parameter strExpr needs be a STRING value. The second
parameter fromPattern is the incoming date[and time] format.
The last parameter represents the target date[and time] format.
CONVERT_TIME(strExpr, fromPattern, toPattern)
CURDATE
CURRENT_DATE
Provides the current date value. For JSON records the result
is a human readable date value represented as yyyy-MM-dd.
For AVRO records the resulting field will be of type INT and
will have the logical type DATE attached
CURDATE()/CURRENT_DATE()
CURRENT_DATETIME
NOW
CURTIME
Provides the current date and time. For JSON records the
result is a human readable date and time value represented
as yyyy-MM-dd'T'HH:mm:ss.SSSZ. For AVRO records the resulting
field will be of type LONG and will have the
the logical type TIMESTAMP attached
NOW()/CURTIME()/CURRENT_DATETIME()
ARRAY_SIZE
Returns the count of elements contained by the parameter.
It is expected the parameter, evaluates to
an array structure.
ARRAY_SIZE(EXPR)
REGEXP
Returns the matched groups otherwise null.
Consider this regular expression (Mr|Mrs|Ms) ([A-Z][a-z]+) ([A-Z][a-z]+)
and this input Ms Jane Smith; the return values are:
["Ms Jane Smith", "Ms", "Jane", "Smith"].
REGEXP(SQL_EXPR, REGEX_EXPR)
REGEXP_LIKE
Returns true if the input value matches the expression
otherwise false.
REGEXP_LIKE(SQL_EXPR, REGEX_EXPR)
REGEXP_REPLACE
Replace the matched text with the provided value.
If there’s no match the input will
remain the same.
REGEXP_REPLACE(SQL_EXPR, SQL_EXPR, REGEX_EXPR)
EXISTS
Returns true if the given field is present; false otherwise.
EXISTS(FIELD_EXPR)
HEADERASSTRING
Returns the value of the record header key as
a STRING value.
HEADERASSTRING('HEADER_KEY')
HEADERASINT
Returns the value of the record header key as
an INT value.
HEADERASINT('HEADER_KEY')
HEADERASLONG
Returns the value of the record header key as
a LONG value.
HEADERASLONG('HEADER_KEY')
HEADERASDOUBLE
Returns the value of the record header key as
a DOUBLE value.
HEADERASDOUBLE('HEADER_KEY')
HEADERASFLOAT
Returns the value of the record header key as
a FLOAT value.
HEADERASFLOAT('HEADER_KEY')
HEADERKEYS
Returns all the header keys for the current
record.
HEADERKEYS()

Anonymize your data

At times you might not want the data published to a topic to contain sensitive information. Therefore when a SQL Processor is created you might need to anonymize some of the data. The grammar supports such a construct via the ANONYMIZE function.

SELECT anonymize(username)
        , _key as card_number
        , lastTransactionTimestamp
FROM credit_cards