- Release Notes
- Introduction to CelerData Cloud Serverless
- Quick Start
- Sign up for CelerData Cloud Serverless
- A quick tour of the console
- Connect to CelerData Cloud Serverless
- Create an IAM integration
- Create and assign a warehouse
- Create an external catalog
- Load data from cloud storage
- Load data from Apache Kafka/Confluent Cloud
- Try your first query
- Invite new users
- Design data access control policy
- Warehouses
- Catalog, database, table, view, and MV
- Overview of database objects
- Catalog
- Table types
- Asynchronous materialized views
- Data Loading
- Data access control
- Networking and private connectivity
- Usage and Billing
- Organization and Account
- Integration
- Query Acceleration
- Reference
- AWS IAM policies
- Information Schema
- Overview
- be_bvars
- be_cloud_native_compactions
- be_compactions
- character_sets
- collations
- column_privileges
- columns
- engines
- events
- global_variables
- key_column_usage
- load_tracking_logs
- loads
- materialized_views
- partitions
- pipe_files
- pipes
- referential_constraints
- routines
- schema_privileges
- schemata
- session_variables
- statistics
- table_constraints
- table_privileges
- tables
- tables_config
- task_runs
- tasks
- triggers
- user_privileges
- views
- Data Types
- System Metadatabase
- Keywords
- SQL Statements
- Account Management
- Data Definition
- CREATE TABLE
- ALTER TABLE
- DROP CATALOG
- CREATE TABLE LIKE
- REFRESH EXTERNAL TABLE
- RESTORE
- SET CATALOG
- DROP TABLE
- RECOVER
- USE
- CREATE MATERIALIZED VIEW
- DROP DATABASE
- ALTER MATERIALIZED VIEW
- DROP REPOSITORY
- CANCEL RESTORE
- DROP INDEX
- DROP MATERIALIZED VIEW
- CREATE DATABASE
- CREATE TABLE AS SELECT
- BACKUP
- CANCEL BACKUP
- CREATE REPOSITORY
- CREATE INDEX
- Data Manipulation
- INSERT
- SHOW CREATE DATABASE
- SHOW BACKUP
- SHOW ALTER MATERIALIZED VIEW
- SHOW CATALOGS
- SHOW CREATE MATERIALIZED VIEW
- SELECT
- SHOW ALTER
- SHOW MATERIALIZED VIEW
- RESUME ROUTINE LOAD
- ALTER ROUTINE LOAD
- SHOW TABLES
- STREAM LOAD
- SHOW PARTITIONS
- CANCEL REFRESH MATERIALIZED VIEW
- SHOW CREATE CATALOG
- SHOW ROUTINE LOAD TASK
- SHOW RESTORE
- CREATE ROUTINE LOAD
- STOP ROUTINE LOAD
- SHOW DATABASES
- BROKER LOAD
- SHOW ROUTINE LOAD
- PAUSE ROUTINE LOAD
- SHOW SNAPSHOT
- SHOW CREATE TABLE
- CANCEL LOAD
- REFRESH MATERIALIZED VIEW
- SHOW REPOSITORIES
- SHOW LOAD
- Administration
- DESCRIBE
- SQL Functions
- Function List
- String Functions
- CONCAT
- HEX
- LOWER
- SPLIT
- LPAD
- SUBSTRING
- PARSE_URL
- INSTR
- REPEAT
- LCASE
- REPLACE
- HEX_DECODE_BINARY
- RPAD
- SPLIT_PART
- STRCMP
- SPACE
- CHARACTER_LENGTH
- URL_ENCODE
- APPEND_TAILING_CHAR_IF_ABSENT
- LTRIM
- HEX_DECODE_STRING
- URL_DECODE
- LEFT
- STARTS_WITH
- CONCAT
- GROUP_CONCAT
- STR_TO_MAP
- STRLEFT
- STRRIGHT
- MONEY_FORMAT
- RIGHT
- SUBSTRING_INDEX
- UCASE
- TRIM
- FIND_IN_SET
- RTRIM
- ASCII
- UPPER
- REVERSE
- LENGTH
- UNHEX
- ENDS_WITH
- CHAR_LENGTH
- NULL_OR_EMPTY
- LOCATE
- CHAR
- Predicate Functions
- Map Functions
- Binary Functions
- Geospatial Functions
- Lambda Expression
- Utility Functions
- Bitmap Functions
- BITMAP_SUBSET_LIMIT
- TO_BITMAP
- BITMAP_AGG
- BITMAP_FROM_STRING
- BITMAP_OR
- BITMAP_REMOVE
- BITMAP_AND
- BITMAP_TO_BASE64
- BITMAP_MIN
- BITMAP_CONTAINS
- SUB_BITMAP
- BITMAP_UNION
- BITMAP_COUNT
- BITMAP_UNION_INT
- BITMAP_XOR
- BITMAP_UNION_COUNT
- BITMAP_HAS_ANY
- BITMAP_INTERSECT
- BITMAP_AND_NOT
- BITMAP_TO_STRING
- BITMAP_HASH
- INTERSECT_COUNT
- BITMAP_EMPTY
- BITMAP_MAX
- BASE64_TO_ARRAY
- BITMAP_TO_ARRAY
- Struct Functions
- Aggregate Functions
- RETENTION
- MI
- MULTI_DISTINCT_SUM
- WINDOW_FUNNEL
- STDDEV_SAMP
- GROUPING_ID
- HLL_HASH
- AVG
- HLL_UNION_AGG
- COUNT
- BITMAP
- HLL_EMPTY
- SUM
- MAX_BY
- PERCENTILE_CONT
- COVAR_POP
- PERCENTILE_APPROX
- HLL_RAW_AGG
- STDDEV
- CORR
- COVAR_SAMP
- MIN_BY
- MAX
- VAR_SAMP
- STD
- HLL_UNION
- APPROX_COUNT_DISTINCT
- MULTI_DISTINCT_COUNT
- VARIANCE
- ANY_VALUE
- COUNT_IF
- GROUPING
- PERCENTILE_DISC
- Array Functions
- ARRAY_CUM_SUM
- ARRAY_MAX
- ARRAY_LENGTH
- ARRAY_REMOVE
- UNNEST
- ARRAY_SLICE
- ALL_MATCH
- ARRAY_CONCAT
- ARRAY_SORT
- ARRAY_POSITION
- ARRAY_DIFFERENCE
- ARRAY_CONTAINS
- ARRAY_JOIN
- ARRAY_INTERSECT
- CARDINALITY
- ARRAY_CONTAINS_ALL
- ARRAYS_OVERLAP
- ARRAY_MIN
- ARRAY_MAP
- ELEMENT_AT
- ARRAY_APPEND
- ARRAY_SORTBY
- ARRAY_TO_BITMAP
- ARRAY_GENERATE
- ARRAY_AVG
- ARRAY_FILTER
- ANY_MATCH
- REVERSE
- ARRAY_AGG
- ARRAY_DISTINCT
- ARRAY_SUM
- Condition Functions
- Math Functions
- Date and Time Functions
- DAYNAME
- MINUTE
- FROM_UNIXTIME
- HOUR
- MONTHNAME
- MONTHS_ADD
- ADD_MONTHS
- DATE_SUB
- PREVIOUS_DAY
- TO_TERA_DATA
- MINUTES_SUB
- WEEKS_ADD
- HOURS_DIFF
- UNIX_TIMESTAMP
- DAY
- DATE_SLICE
- DATE
- CURTIME
- SECONDS_SUB
- MONTH
- WEEK
- TO_DATE
- TIMEDIFF
- MONTHS_DIFF
- STR_TO_JODATIME
- WEEK_ISO
- MICROSECONDS_SUB
- TIME_SLICE
- MAKEDATE
- DATE_TRUNC
- JODATIME
- DAYOFWEEK
- YEARS_SUB
- TIMESTAMP_ADD
- HOURS_SUB
- STR2DATE
- TIMESTAMP
- FROM_DAYS
- WEEK_OF_YEAR
- YEAR
- TIMESTAMP_DIFF
- TO_TERA_TIMESTAMP
- DAYOFMONTH
- DAYOFYEAR
- DATE_FORMAT
- MONTHS_SUB
- NEXT_DAY
- MINUTES_DIFF
- DATA_ADD
- MINUTES_ADD
- CURDATE
- DAY_OF_WEEK_ISO
- CURRENt_TIMESTAMP
- STR_TO_DATE
- LAST_DAY
- WEEKS_SUB
- TO_DAYS
- DATEDIFF
- NOW
- TO_ISO8601
- TIME_TO_SEC
- QUARTER
- SECONDS_DIFF
- UTC_TIMESTAMP
- DATA_DIFF
- SECONDS_ADD
- ADDDATE
- WEEKSDIFF
- CONVERT_TZ
- MICROSECONDS_ADD
- SECOND
- YEARS_DIFF
- YEARS_ADD
- HOURS_ADD
- DAYS_SUB
- DAYS_DIFF
- Cryptographic Functions
- Percentile Functions
- Bit Functions
- JSON Functions
- Hash Functions
- Scalar Functions
- Table Functions
to_json
Description
Converts a Map or Struct value into a JSON string. If the input value is NULL, NULL is returned.
If you want to cast values of other data types, see cast.
Syntax
to_json(any_value)
Parameters
any_value
: the Map or Struct expression you want to convert. If the input value is invalid, an error is returned. The value in each key-value pair of the Map or Struct value is nullable. See the last example.
Return value
Returns a JSON value.
Examples
select to_json(map{1:'a',2:'b'});
+---------------------------+
| to_json(map{1:'a',2:'b'}) |
+---------------------------+
| {"1": "a", "2": "b"} |
+---------------------------+
select to_json(row('asia','eu'));
+--------------------------------+
| to_json(row('asia', 'eu')) |
+--------------------------------+
| {"col1": "asia", "col2": "eu"} |
+--------------------------------+
select to_json(map('a', named_struct('b', 1)));
+----------------------------------------+
| to_json(map{'a':named_struct('b', 1)}) |
+----------------------------------------+
| {"a": {"b": 1}} |
+----------------------------------------+
select to_json(named_struct("k1", cast(null as string), "k2", "v2"));
+-----------------------------------------------------------------------+
| to_json(named_struct('k1', CAST(NULL AS VARCHAR(65533)), 'k2', 'v2')) |
+-----------------------------------------------------------------------+
| {"k1": null, "k2": "v2"} |
+-----------------------------------------------------------------------+