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    • Create and Manage Data Stores
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      • Explore Data Store and Topic Details
      • Use Multiple Data Stores in Queries
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      • Inviting Users to an Organization
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      • Using the CLI to Manage User Roles
      • Example: Setting Up Custom Roles for Production and Stage
    • Create DeltaStream Objects to Structure Raw Data
    • Use Namespacing for Organizing Data
    • Create and Query Materialized Views
    • Create a Compute Pool to Work with Iceberg
    • Create a Function
    • Secure my Connection to a Data Store
      • Introducing DeltaStream Private Links
      • Creating an AWS Private Link from DeltaStream to your Confluent Kafka Dedicated Cluster
      • Enabling Private Link Connectivity to Confluent Enterprise Cluster and Schema Registry
      • Creating a Private Link from DeltaStream to Amazon MSK
      • Creating a Private Link for RDS Databases
      • Deleting a Private Link
    • Serialize my Data
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      • Configuring Deserialization Error Handling
  • Integrations
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  • Setting up Enterprise Security Integrations
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  • use cases
    • Using an AWS S3 Store as a Source to Feed an MSK Topic
  • Reference
    • Metrics
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    • SQL Syntax
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        • Serializing with JSON
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        • ACCEPT INVITATION
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        • PRINT ENTITY
        • REJECT INVITATION
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        • SET DEFAULT
        • USE
        • START COMPUTE_POOL
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      • DDL
        • ALTER API_TOKEN
        • ALTER SECURITY INTEGRATION
        • CREATE API_TOKEN
        • CREATE CHANGELOG
        • CREATE COMPUTE_POOL
        • CREATE DATABASE
        • CREATE DESCRIPTOR_SOURCE
        • CREATE ENTITY
        • CREATE FUNCTION_SOURCE
        • CREATE FUNCTION
        • CREATE INDEX
        • CREATE METRICS INTEGRATION
        • CREATE ORGANIZATION
        • CREATE ROLE
        • CREATE SCHEMA_REGISTRY
        • CREATE SCHEMA
        • CREATE SECRET
        • CREATE SECURITY INTEGRATION
        • CREATE STORE
        • CREATE STREAM
        • CREATE TABLE
        • DROP API_TOKEN
        • DROP CHANGELOG
        • DROP COMPUTE_POOL
        • DROP DATABASE
        • DROP DESCRIPTOR_SOURCE
        • DROP ENTITY
        • DROP FUNCTION_SOURCE
        • DROP FUNCTION
        • DROP METRICS INTEGRATION
        • DROP RELATION
        • DROP ROLE
        • DROP SCHEMA
        • DROP SCHEMA_REGISTRY
        • DROP SECRET
        • DROP SECURITY INTEGRATION
        • DROP STORE
        • DROP STREAM
        • DROP USER
        • START/STOP COMPUTE_POOL
        • UPDATE COMPUTE_POOL
        • UPDATE ENTITY
        • UPDATE SCHEMA_REGISTRY
        • UPDATE SECRET
        • UPDATE STORE
      • Query
        • APPLICATION
        • Change Data Capture (CDC)
        • CREATE CHANGELOG AS SELECT
        • CREATE STREAM AS SELECT
        • CREATE TABLE AS SELECT
        • Function
          • Built-in Functions
          • Row Metadata Functions
        • INSERT INTO
        • Materialized View
          • CREATE MATERIALIZED VIEW AS
          • SELECT (FROM MATERIALIZED VIEW)
        • Query Name and Version
        • Resume Query
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        • SELECT
          • FROM
          • JOIN
          • MATCH_RECOGNIZE
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        • TERMINATE QUERY
      • Sandbox
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      • Row Key Definition
    • DeltaStream OpenAPI
      • Deltastream
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On this page
  • Syntax
  • Description
  • Arguments
  • Function Parameters
  • Example
  1. Reference
  2. SQL Syntax
  3. DDL

CREATE FUNCTION

PreviousCREATE FUNCTION_SOURCENextCREATE INDEX

Last updated 2 months ago

Note Only valid for approved organizations. Please .

Syntax

CREATE FUNCTION
    function_name (arg_name arg_type [, ...])
    RETURNS return_type
    LANGUAGE language_name
WITH (function_parameter = value [, ...]);

Description

Defines a new (UDF), an executable routine defined in a supported language, which accepts an ordered list of input arguments, performs a computation, and generates a result value.

The name and parameter types of a function’s signature must be unique within an organization. The signature is a combination of the name, parameter types, and return type of the function.

See the tutorial for a full example of adding a .

Arguments

function_name

Name of the function to create. If the name is case sensitive you must wrap it in double quotes; otherwise the system uses the lower case name.

(arg_name arg_type [,…​])

An ordered list of function argument names and types.

return_type

Data type for a function’s result value.

language_name

Language in which the function was created. Supports JAVA.

WITH (function_parameter = value [, …​ ])

Function Parameters

Parameter Name
Description

source.name

class.name

Required. Specifies the fully-qualified class name defined within a function source. Type: String Valid values: A valid class name in the function_source.

egress.allow.uris

Optional. Specifies a comma delimited list of host:port endpoints that the function can send requests. This is only needed if a function needs to call a remote service.

Example

Create user-defined function with single input argument

CREATE FUNCTION
    "toUpperCase" (s VARCHAR)
    RETURNS VARCHAR
    LANGUAGE JAVA
    WITH ( 'source.name' = 'mysrc', 'class.name' = 'util.UpperCase' );

You can use LIST FUNCTIONS command to get a list of created functions.

Create user-defined function with multiple input arguments

The below DDL statement creates a new user-defined function called getrate from a Java class with the name accounting.Exchange available in the finance function source. This function receives two input arguments of data types VARCHAR and BIGINT, and generates an output of the data type DECIMAL.

CREATE FUNCTION
    getrate (name VARCHAR, amount BIGINT)
    RETURNS DECIMAL
    LANGUAGE JAVA
    WITH ( 'source.name' = 'finance', 'class.name' = 'accounting.Exchange' );

Create user-defined function with egress.allow.uris property

The below DDL statement creates a new user-defined function called getrate from a Java class with the name accounting.Exchange available in the finance function source. This function receives two input arguments of data types VARCHAR and BIGINT, and generates an output of the data type DECIMAL.

This function will can also make remote calls to myhost1:9090 and myhost2:80. Without the egress.allow.uris property, the function calls are blocked.

CREATE FUNCTION
    getrate (name VARCHAR, amount BIGINT)
    RETURNS DECIMAL
    LANGUAGE JAVA
    WITH ( 'source.name' = 'finance', 'class.name' = 'accounting.Exchange', 'egress.allow.uris'='myhost1:9090,myhost2:80' );

This clause specifies the .

Required. Specifies an existing function Source to use for the content of the function. See . Type: String Valid values: A function_source to which the user has access. See .

The below DDL statement creates a new user-defined function with the name toUpperCase. The function accepts one argument of the data type VARCHAR; the data type of its return value is also VARCHAR. The function's executable code is in a Java class with the name util.UpperCase available in the mysrc function source. Check for details on how to add a function source.

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Creating a Function
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CREATE FUNCTION SOURCE
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LIST FUNCTION_SOURCES
LIST FUNCTION_SOURCES