Expressions

Expressions

col(name)	Creates an expression which refers to a table's column.
lit(v[, data_type])	Creates a SQL literal.
range_(start, end)	Indicates a range from 'start' to 'end', which can be used in columns selection.
and_(predicate0, predicate1, *predicates)	Boolean AND in three-valued logic.
or_(predicate0, predicate1, *predicates)	Boolean OR in three-valued logic.
not_(expression)	Inverts a given boolean expression.
current_database()	Returns the current database
current_date()	Returns the current SQL date in local time zone.
current_time()	Returns the current SQL time in local time zone.
current_timestamp()	Returns the current SQL timestamp in local time zone, the return type of this expression is TIMESTAMP_LTZ.
current_watermark(rowtimeAttribute)	Returns the current watermark for the given rowtime attribute, or NULL if no common watermark of all upstream operations is available at the current operation in the pipeline.
local_time()	Returns the current SQL time in local time zone.
local_timestamp()	Returns the current SQL timestamp in local time zone, the return type of this expression s TIMESTAMP.
to_date(date_str[, format])	Converts the date string with the given format (by default 'yyyy-MM-dd') to a date.
to_timestamp(timestamp_str[, format])	Converts the date time string with the given format (by default: 'yyyy-MM-dd HH:mm:ss') under the 'UTC+0' time zone to a timestamp.
to_timestamp_ltz(numeric_epoch_time, precision)	Converts a numeric type epoch time to TIMESTAMP_LTZ.
temporal_overlaps(left_time_point, ...)	Determines whether two anchored time intervals overlap.
date_format(timestamp, format)	Formats a timestamp as a string using a specified format.
timestamp_diff(time_point_unit, time_point1, ...)	Returns the (signed) number of TimePointUnit between time_point1 and time_point2.
convert_tz(date_str, tz_from, tz_to)	Converts a datetime string date_str (with default ISO timestamp format 'yyyy-MM-dd HH:mm:ss') from time zone tz_from to time zone tz_to.
from_unixtime(unixtime[, format])	Converts unix timestamp (seconds since '1970-01-01 00:00:00' UTC) to datetime string the given format.
unix_timestamp([date_str, format])	Gets the current unix timestamp in seconds if no arguments are not specified.
array(head, *tail)	Creates an array of literals.
row(head, *tail)	Creates a row of expressions.
map_(key, value, *tail)	Creates a map of expressions.
map_from_arrays(key, value)	Creates a map from an array of keys and an array of values.
row_interval(rows)	Creates an interval of rows.
pi()	Returns a value that is closer than any other value to pi.
e()	Returns a value that is closer than any other value to e.
rand([seed])	Returns a pseudorandom double value between 0.0 (inclusive) and 1.0 (exclusive) with a initial seed if specified.
rand_integer(bound[, seed])	Returns a pseudorandom integer value between 0 (inclusive) and the specified value (exclusive) with a initial seed if specified.
atan2(y, x)	Calculates the arc tangent of a given coordinate.
negative(v)	Returns negative numeric.
concat(first, *others)	Returns the string that results from concatenating the arguments.
concat_ws(separator, first, *others)	Returns the string that results from concatenating the arguments and separator.
uuid()	Returns an UUID (Universally Unique Identifier) string (e.g., "3d3c68f7-f608-473f-b60c-b0c44ad4cc4e") according to RFC 4122 type 4 (pseudo randomly generated) UUID.
null_of(data_type)	Returns a null literal value of a given data type.
log(v[, base])	If base is specified, calculates the logarithm of the given value to the given base.
source_watermark()	Source watermark declaration for schema.
if_then_else(condition, if_true, if_false)	Ternary conditional operator that decides which of two other expressions should be evaluated based on a evaluated boolean condition.
coalesce(*args)	Returns the first argument that is not NULL.
with_columns(head, *tails)	Creates an expression that selects a range of columns.
without_columns(head, *tails)	Creates an expression that selects all columns except for the given range of columns.
json_string(value)	Serializes a value into JSON.
json_object([on_null])	Builds a JSON object string from a list of key-value pairs.
json_object_agg(on_null, key_expr, value_expr)	Builds a JSON object string by aggregating key-value expressions into a single JSON object.
json_array([on_null])	Builds a JSON array string from a list of values.
json_array_agg(on_null, item_expr)	Builds a JSON object string by aggregating items into an array.
call(f, *args)	The first parameter f could be a str or a Python user-defined function.
call_sql(sql_expression)	A call to a SQL expression.

Expression

arithmetic functions

Expression.exp	Calculates the Euler's number raised to the given power.
Expression.log10	Calculates the base 10 logarithm of the given value.
Expression.log2	Calculates the base 2 logarithm of the given value.
Expression.ln	Calculates the natural logarithm of the given value.
Expression.log([base])	Calculates the natural logarithm of the given value if base is not specified.
Expression.cosh	Calculates the hyperbolic cosine of a given number.
Expression.sinh	Calculates the hyperbolic sine of a given number.
Expression.sin	Calculates the sine of a given number.
Expression.cos	Calculates the cosine of a given number.
Expression.tan	Calculates the tangent of a given number.
Expression.cot	Calculates the cotangent of a given number.
Expression.asin	Calculates the arc sine of a given number.
Expression.acos	Calculates the arc cosine of a given number.
Expression.atan	Calculates the arc tangent of a given number.
Expression.tanh	Calculates the hyperbolic tangent of a given number.
Expression.degrees	Converts numeric from radians to degrees.
Expression.radians	Converts numeric from degrees to radians.
Expression.sqrt	Calculates the square root of a given value.
Expression.abs	Calculates the absolute value of given value.
Expression.sign	Calculates the signum of a given number.
Expression.round(places)	Rounds the given number to integer places right to the decimal point.
Expression.between(lower_bound, upper_bound)	Returns true if the given expression is between lower_bound and upper_bound (both inclusive).
Expression.not_between(lower_bound, upper_bound)	Returns true if the given expression is not between lower_bound and upper_bound (both inclusive).
Expression.then(if_true, if_false)	Ternary conditional operator that decides which of two other expressions should be evaluated based on a evaluated boolean condition.
Expression.if_null(null_replacement)	Returns null_replacement if the given expression is null; otherwise the expression is returned.
Expression.is_null	Returns true if the given expression is null.
Expression.is_not_null	Returns true if the given expression is not null.
Expression.is_true	Returns true if given boolean expression is true.
Expression.is_false	Returns true if given boolean expression is false.
Expression.is_not_true	Returns true if given boolean expression is not true (for null and false).
Expression.is_not_false	Returns true if given boolean expression is not false (for null and true).
Expression.distinct	Similar to a SQL distinct aggregation clause such as COUNT(DISTINCT a), declares that an aggregation function is only applied on distinct input values.
Expression.sum	Returns the sum of the numeric field across all input values.
Expression.sum0	Returns the sum of the numeric field across all input values.
Expression.min	Returns the minimum value of field across all input values.
Expression.max	Returns the maximum value of field across all input values.
Expression.count	Returns the number of input rows for which the field is not null.
Expression.avg	Returns the average (arithmetic mean) of the numeric field across all input values.
Expression.first_value	Returns the first value of field across all input values.
Expression.last_value	Returns the last value of field across all input values.
Expression.list_agg([separator])	Concatenates the values of string expressions and places separator values between them.
Expression.stddev_pop	Returns the population standard deviation of an expression(the square root of var_pop).
Expression.stddev_samp	Returns the sample standard deviation of an expression(the square root of var_samp).
Expression.var_pop	Returns the population standard variance of an expression.
Expression.var_samp	Returns the sample variance of a given expression.
Expression.collect	Returns multiset aggregate of a given expression.
Expression.alias(name, *extra_names)	Specifies a name for an expression i.e. a field.
Expression.cast(data_type)	Returns a new value being cast to type type.
Expression.try_cast(data_type)	Like cast, but in case of error, returns NULL rather than failing the job.
Expression.asc	Specifies ascending order of an expression i.e. a field for order_by.
Expression.desc	Specifies descending order of an expression i.e. a field for order_by.
Expression.in_(first_element_or_table, ...)	If first_element_or_table is a Table, Returns true if an expression exists in a given table sub-query.
Expression.start	Returns the start time (inclusive) of a window when applied on a window reference.
Expression.end	Returns the end time (exclusive) of a window when applied on a window reference.
Expression.bin	Returns a string representation of an integer numeric value in binary format.
Expression.hex	Returns a string representation of an integer numeric value or a string in hex format.
Expression.truncate([n])	Returns a number of truncated to n decimal places.

string functions

Expression.substring(begin_index[, length])	Creates a substring of the given string at given index for a given length.
Expression.substr(begin_index[, length])	Creates a substring of the given string at given index for a given length.
Expression.trim_leading([character])	Removes leading space characters from the given string if character is None.
Expression.trim_trailing([character])	Removes trailing space characters from the given string if character is None.
Expression.trim([character])	Removes leading and trailing space characters from the given string if character is None.
Expression.replace([search, replacement])	Returns a new string which replaces all the occurrences of the search target with the replacement string (non-overlapping).
Expression.char_length	Returns the length of a string.
Expression.upper_case	Returns all of the characters in a string in upper case using the rules of the default locale.
Expression.lower_case	Returns all of the characters in a string in lower case using the rules of the default locale.
Expression.init_cap	Converts the initial letter of each word in a string to uppercase.
Expression.like([pattern])	Returns true, if a string matches the specified LIKE pattern.
Expression.similar([pattern])	Returns true, if a string matches the specified SQL regex pattern.
Expression.position([haystack])	Returns the position of string in an other string starting at 1.
Expression.lpad(length, pad)	Returns a string left-padded with the given pad string to a length of len characters.
Expression.rpad(length, pad)	Returns a string right-padded with the given pad string to a length of len characters.
Expression.overlay(new_string, starting[, ...])	Replaces a substring of string with a string starting at a position (starting at 1).
Expression.regexp(regex)	Returns True if any (possibly empty) substring matches the regular expression, otherwise False.
Expression.regexp_replace(regex, replacement)	Returns a string with all substrings that match the regular expression consecutively being replaced.
Expression.regexp_extract(regex[, extract_index])	Returns a string extracted with a specified regular expression and a regex match group index.
Expression.from_base64	Returns the base string decoded with base64.
Expression.to_base64	Returns the base64-encoded result of the input string.
Expression.ascii	Returns the numeric value of the first character of the input string.
Expression.chr	Returns the ASCII character result of the input integer.
Expression.decode(charset)	Decodes the first argument into a String using the provided character set.
Expression.encode(charset)	Encodes the string into a BINARY using the provided character set.
Expression.left(length)	Returns the leftmost integer characters from the input string.
Expression.right(length)	Returns the rightmost integer characters from the input string.
Expression.instr(s)	Returns the position of the first occurrence in the input string.
Expression.locate(s[, pos])	Returns the position of the first occurrence in the input string after position integer.
Expression.parse_url(part_to_extract[, key])	Parse url and return various parameter of the URL.
Expression.ltrim	Returns a string that removes the left whitespaces from the given string.
Expression.rtrim	Returns a string that removes the right whitespaces from the given string.
Expression.repeat(n)	Returns a string that repeats the base string n times.
Expression.over(alias)	Defines an aggregation to be used for a previously specified over window.
Expression.reverse	Reverse each character in current string.
Expression.split_index(separator, index)	Split target string with custom separator and pick the index-th(start with 0) result.
Expression.str_to_map([list_delimiter, ...])	Creates a map by parsing text.

temporal functions

Expression.to_date	Parses a date string in the form "yyyy-MM-dd" to a SQL Date.
Expression.to_time	Parses a time string in the form "HH:mm:ss" to a SQL Time.
Expression.to_timestamp	Parses a timestamp string in the form "yyyy-MM-dd HH:mm:ss[.SSS]" to a SQL Timestamp.
Expression.extract(time_interval_unit)	Extracts parts of a time point or time interval.
Expression.floor([time_interval_unit])	If time_interval_unit is specified, it rounds down a time point to the given unit, e.g.
Expression.ceil([time_interval_unit])	If time_interval_unit is specified, it rounds up a time point to the given unit, e.g.

advanced type helper functions

Expression.get(name_or_index)	Accesses the field of a Flink composite type (such as Tuple, POJO, etc.) by name or index and returns it's value.
Expression.flatten	Converts a Flink composite type (such as Tuple, POJO, etc.) and all of its direct subtypes into a flat representation where every subtype is a separate field.
Expression.at(index)	Accesses the element of an array or map based on a key or an index (starting at 1).
Expression.cardinality	Returns the number of elements of an array or number of entries of a map.
Expression.element	Returns the sole element of an array with a single element.
Expression.array_concat(*arrays)	Returns an array that is the result of concatenating at least one array.
Expression.array_contains(needle)	Returns whether the given element exists in an array.
Expression.array_distinct()	Returns an array with unique elements.
Expression.array_join(delimiter[, ...])	Returns a string that represents the concatenation of the elements in the given array and the elements' data type in the given array is string.
Expression.array_position(needle)	Returns the position of the first occurrence of element in the given array as int.
Expression.array_remove(needle)	Removes all elements that equal to element from array.
Expression.array_reverse()	Returns an array in reverse order.
Expression.array_max()	Returns the maximum value from the array.
Expression.array_slice(start_offset[, ...])	Returns a subarray of the input array between 'start_offset' and 'end_offset' inclusive.
Expression.array_min()	Returns the minimum value from the array.
Expression.array_union(array)	Returns an array of the elements in the union of array1 and array2, without duplicates.
Expression.map_entries	Returns an array of all entries in the given map.
Expression.map_keys	Returns the keys of the map as an array.
Expression.map_values	Returns the values of the map as an array.

time definition functions

Expression.rowtime	Declares a field as the rowtime attribute for indicating, accessing, and working in Flink's event time.
Expression.proctime	Declares a field as the proctime attribute for indicating, accessing, and working in Flink's processing time.
Expression.year	Creates an interval of the given number of years.
Expression.years	Creates an interval of the given number of years.
Expression.quarter	Creates an interval of the given number of quarters.
Expression.quarters	Creates an interval of the given number of quarters.
Expression.month	Creates an interval of the given number of months.
Expression.months	Creates an interval of the given number of months.
Expression.week	Creates an interval of the given number of weeks.
Expression.weeks	Creates an interval of the given number of weeks.
Expression.day	Creates an interval of the given number of days.
Expression.days	Creates an interval of the given number of days.
Expression.hour	Creates an interval of the given number of hours.
Expression.hours	Creates an interval of the given number of hours.
Expression.minute	Creates an interval of the given number of minutes.
Expression.minutes	Creates an interval of the given number of minutes.
Expression.second	Creates an interval of the given number of seconds.
Expression.seconds	Creates an interval of the given number of seconds.
Expression.milli	Creates an interval of the given number of millis.
Expression.millis	Creates an interval of the given number of millis.

hash functions

Expression.md5	Returns the MD5 hash of the string argument; null if string is null.
Expression.sha1	Returns the SHA-1 hash of the string argument; null if string is null.
Expression.sha224	Returns the SHA-224 hash of the string argument; null if string is null.
Expression.sha256	Returns the SHA-256 hash of the string argument; null if string is null.
Expression.sha384	Returns the SHA-384 hash of the string argument; null if string is null.
Expression.sha512	Returns the SHA-512 hash of the string argument; null if string is null.
Expression.sha2(hash_length)	Returns the hash for the given string expression using the SHA-2 family of hash functions (SHA-224, SHA-256, SHA-384, or SHA-512).

JSON functions

Expression.is_json([json_type])	Determine whether a given string is valid JSON.
Expression.json_exists(path[, on_error])	Determines whether a JSON string satisfies a given search criterion.
Expression.json_value(path[, ...])	Extracts a scalar from a JSON string.
Expression.json_query(path[, ...])	Extracts JSON values from a JSON string.