Flink SQL Functions in Confluent Cloud for Apache Flink

Confluent Cloud for Apache Flink® enables you to do data transformations and other operations with the following built-in functions.

• Aggregate Functions

• Changelog Conversion Functions

• Collection Functions

• Comparison Functions

• Conditional Functions

• Datetime Functions

• Hash Functions

• JSON Functions

• ML Preprocessing Functions

• Model Inference Functions

• Numeric Functions

• Search Functions

• String Functions

• Table API Functions

Not every Flink SQL keyword is categorized as a function. For example, UNNEST is documented as array expansion on the Join Queries page.

All functions, A to Z

Use the following table to find the category for a specific function.

Function	Category
ABS	Numeric
ACOS	Numeric
AI_COMPLETE	Model Inference
AI_DETECT_ANOMALIES	Model Inference
AI_DETECT_PII	Model Inference
AI_EMBEDDING	Model Inference
AI_FORECAST	Model Inference
AI_RUN_AGENT	Model Inference
AI_SENTIMENT	Model Inference
AI_TOOL_INVOKE	Model Inference
ARRAY	Collection
ARRAY_AGG	Collection
ARRAY_APPEND	Collection
ARRAY_CONCAT	Collection
ARRAY_CONTAINS	Collection
ARRAY_DISTINCT	Collection
ARRAY_EXCEPT	Collection
ARRAY_INTERSECT	Collection
ARRAY_JOIN	Collection
ARRAY_MAX	Collection
ARRAY_MIN	Collection
ARRAY_POSITION	Collection
ARRAY_PREPEND	Collection
ARRAY_REMOVE	Collection
ARRAY_REVERSE	Collection
ARRAY_SLICE	Collection
ARRAY_SORT	Collection
ARRAY_UNION	Collection
ASCII	String
ASIN	Numeric
ATAN	Numeric
ATAN2	Numeric
AVG	Aggregate
BETWEEN	Comparison
BIN	Numeric
BTRIM	String
CARDINALITY(array)	Collection
CARDINALITY(map)	Collection
CASE	Conditional
CASE WHEN CONDITION	Conditional
CAST	Comparison
CEIL	Datetime
CEILING	Numeric
CHARACTER_LENGTH	String
CHR	String
COALESCE	Conditional
COLLECT	Aggregate
CONCAT	String
CONCAT_WS	String
CONVERT_TZ	Datetime
COS	Numeric
COSH	Numeric
COT	Numeric
COUNT	Aggregate
CUME_DIST	Aggregate
CURRENT_DATE	Datetime
CURRENT_ROW_TIMESTAMP	Datetime
CURRENT_TIME	Datetime
CURRENT_TIMESTAMP	Datetime
CURRENT_WATERMARK	Datetime
DATE	Datetime
DATE_FORMAT	Datetime
DAYOFMONTH	Datetime
DAYOFWEEK	Datetime
DAYOFYEAR	Datetime
DECODE	String
DEGREES	Numeric
DENSE_RANK	Aggregate
E	Numeric
ELEMENT	Collection
ELT	String
ENCODE	String
ENDSWITH	String
EXISTS	Comparison
EXP	Numeric
EXTRACT	Datetime
FIRST_VALUE	Aggregate
FLOOR	Datetime
FLOOR	Numeric
FROM_BASE64	String
FROM_CHANGELOG	Changelog Conversion
FROM_UNIXTIME	Datetime
GREATEST	Conditional
GROUP_ID	Collection
GROUPING	Collection
HEX	Numeric
HOUR	Datetime
IF	Conditional
IFNULL	Conditional
Implicit row constructor	Collection
IN	Comparison
INITCAP	String
INSTR	String
INTERVAL	Datetime
IS_ALPHA	Conditional
IS_DECIMAL	Conditional
IS_DIGIT	Conditional
IS DISTINCT FROM	Comparison
IS JSON	JSON
IS NOT DISTINCT FROM	Comparison
IS NOT NULL	Comparison
IS NULL	Comparison
IS_VALID_UTF8	Comparison
JSON_ARRAY	JSON
JSON_ARRAYAGG	JSON
JSON_EXISTS	JSON
JSON_OBJECT	JSON
JSON_OBJECTAGG	JSON
JSON_QUERY	JSON
JSON_QUOTE	JSON
JSON_STRING	JSON
JSON_UNQUOTE	JSON
JSON_VALUE	JSON
KEY_SEARCH_AGG	Search
LAG	Aggregate
LAST_VALUE	Aggregate
LEAD	Aggregate
LEAST	Conditional
LEFT	String
LIKE	Comparison
LISTAGG	Aggregate
LN	Numeric
LOCALTIME	Datetime
LOCALTIMESTAMP	Datetime
LOCATE	String
LOG	Numeric
LOG10	Numeric
LOG2	Numeric
LOWER	String
LPAD	String
LTRIM	String
MAKE_VALID_UTF8	Comparison
MAP	Collection
MAP_ENTRIES	Collection
MAP_FROM_ARRAYS	Collection
MAP_KEYS	Collection
MAP_UNION	Collection
MAP_VALUES	Collection
MAX	Aggregate
MD5	Hash
MIN	Aggregate
MINUTE	Datetime
ML_BUCKETIZE	ML Preprocessing
ML_CHARACTER_TEXT_SPLITTER	ML Preprocessing
ML_DETECT_ANOMALIES	Model Inference
ML_DETECT_ANOMALIES_ROBUST	Model Inference
ML_EVALUATE	Model Inference
ML_FILE_FORMAT_TEXT_SPLITTER	ML Preprocessing
ML_FORECAST	Model Inference
ML_LABEL_ENCODER	ML Preprocessing
ML_MAX_ABS_SCALER	ML Preprocessing
ML_MIN_MAX_SCALER	ML Preprocessing
ML_NGRAMS	ML Preprocessing
ML_NORMALIZER	ML Preprocessing
ML_ONE_HOT_ENCODER	ML Preprocessing
ML_PREDICT	Model Inference
ML_RECURSIVE_TEXT_SPLITTER	ML Preprocessing
ML_ROBUST_SCALER	ML Preprocessing
ML_STANDARD_SCALER	ML Preprocessing
MONTH	Datetime
NOT BETWEEN	Comparison
NOT IN	Comparison
NOT LIKE	Comparison
NOT SIMILAR TO	Comparison
NOW	Datetime
NTILE	Aggregate
NULLIF	Conditional
OVERLAPS	Datetime
OVERLAY	String
PARSE_URL	String
PERCENT_RANK	Aggregate
PERCENTILE	Numeric
PI	Numeric
POSITION	String
POWER	Numeric
QUARTER	Datetime
RADIANS	Numeric
RAND	Numeric
RAND(INT)	Numeric
RAND_INTEGER(INT)	Numeric
RAND_INTEGER(INT1, INT2)	Numeric
RANK	Aggregate
REGEXP	String
REGEXP_COUNT	String
REGEXP_EXTRACT	String
REGEXP_EXTRACT_ALL	String
REGEXP_INSTR	String
REGEXP_REPLACE	String
REGEXP_SUBSTR	String
REPEAT	String
REPLACE	String
REVERSE	String
RIGHT	String
ROUND	Numeric
ROW_NUMBER	Aggregate
RPAD	String
RTRIM	String
SECOND	Datetime
SHA1	Hash
SHA2	Hash
SHA224	Hash
SHA256	Hash
SHA384	Hash
SHA512	Hash
SIGN	Numeric
SIMILAR TO	Comparison
SIN	Numeric
SINH	Numeric
SOURCE_WATERMARK	Datetime
SPLIT	String
SPLIT_INDEX	String
SQRT	Numeric
STARTSWITH	String
STDDEV_POP	Aggregate
STDDEV_SAMP	Aggregate
STR_TO_MAP	String
string1 || string2	String—see also CONCAT
SUBSTRING	String
SUM	Aggregate
TAN	Numeric
TANH	Numeric
TEXT_SEARCH_AGG	Search
TIME	Datetime
TIMESTAMP	Datetime
TIMESTAMPADD	Datetime
TIMESTAMPDIFF	Datetime
TO_BASE64	String
TO_CHANGELOG	Changelog Conversion
TO_DATE	Datetime
TO_TIMESTAMP	Datetime
TO_TIMESTAMP_LTZ	Datetime
TRANSLATE	String
TRIM	String
TRUNCATE	Numeric
TRY_CAST	Comparison
TYPEOF	Comparison
UNHEX	Numeric
UNIX_TIMESTAMP	Datetime
UNIX_TIMESTAMP	Datetime
UPPER	String
URL_DECODE	String
URL_ENCODE	String
UUID	Numeric
VAR_POP	Aggregate
VAR_SAMP	Aggregate
VARIANCE	Aggregate
VECTOR_SEARCH_AGG	Search
WEEK	Datetime
YEAR	Datetime

Related content

• User-defined Functions

• Create a User Defined Function

• Flink SQL Queries

• DDL Statements