tencent cloud

All product documents
Tencent Cloud WeData
DocumentationTencent Cloud WeDataOperation GuideData DevelopmentTask DevelopmentTask Scheduling ConfigurationParameter Passing
Parameter Passing
Download PDF
Last updated: 2025-04-15 21:38:52
Parameter Passing
Last updated: 2025-04-15 21:38:52
Download PDF

Feature Overview

Used to support the transfer of parameters between upstream and downstream. For example, transmit the calculation results of the current task as parameters to the subtask for use. Multiple results can be transmitted by specifying the object with the column number.
Supported range: Hive SQL, JDBC SQL, Python, Shell, Spark SQL, DLC SQL, Impala, TCHouse-P, DLC PySpark.

Parameter Configuration Instructions

1. Output current task parameters

If you need to transmit parameters from the current task to downstream, select Output current task parameters in Parameter Passing and configure parameter information.
Output parameter passing to subtasks, value in the following two types:
Variables (n, m starting from 0), support transmission of two-dimensional arrays, specific configuration method as follows:
$[n][m]: Retrieve the data of the n-th row and m-th column.
$[n][*]: Represent obtaining the data of the n-th row.
$[*][n]: Indicate obtaining the data of the n-th column.
$[*][*]: Represent retrieving the data of all rows and columns.
$[0]: Represent obtaining the data of the first row and first column.
constant: set constant as output parameter.
For example: Parent task A. The calculation results in code have 3 columns, which are 123, 234, and 1234 respectively. Define an output parameter name mark_id in this configuration. Fill in mark_id = $[0], indicating taking the value of the first row and first column of calculation results.

1. Reference parent task parameters

If the current task needs to refer to the parameters defined in the parent task, check the option of referencing parent task parameters in the parameter passing.
Fill in the definition's import parameters and select the output parameter of the parent task for this parameter value (no options if no parent node). For example: Subtask B. Define any parameter name mark_id. Select the value of node A.mark_id. Use ${mark_id} in code, and ${mark_id} will be replaced with string 123.
Example: As shown in the figure, define parameter name a and take the parameter a defined in the upstream parent task hivesql_1; define parameter name b and take the parameter b defined in the upstream parent task hivesql_1.




Use Case

Divided into three types: SQL type, Shell type, Python type. Following are usage examples of the three types (the following context takes transmitting constants as an example, and supports transmitting variables).
Type
Task type
As Output Party (Upstream)
As Input Party (Downstream)
Remarks
Parameter configuration
Code
Parameter configuration
Code
SQL class
Hive SQL
JDBC SQL
Spark SQL
DLC SQL
Impala
TCHouse-P



SELECT "This is the value of the parameter"


SELECT '${parameter}' AS parameter_value;

Shell class
Shell



echo "This is the value of the parameter"


expr ${parameter}

Python class
Python



print("This is the value of the parameter")


print('${parameter}')

DLC PySpark class
DLC PySpark

from dlcutils import dlcutils

dlcutils.params.save([["param1","param2","param3"],["param4","param5","param6"]])

print('${parameter}')
Usage limitations as the Output Party: Only the DLC engine with kernel versions Standard-S1.1 and Standard-S1.1(native) is supported. This feature is supported for engines created after March 30, 2025. For engines created earlier, an upgrade is required. If you need to upgrade the engine, please contact the DLC operations team.


Was this page helpful?
You can also Contact Sales or Submit a Ticket for help.
Yes
No

Feedback

Contact Us

Contact our sales team or business advisors to help your business.

Contact Us
Technical Support

Open a ticket if you're looking for further assistance. Our Ticket is 7x24 available.

Submit a Ticket
7x24 Phone Support
Hong Kong, China
+852 800 906 020 (Toll Free)
United States
+1 844 606 0804 (Toll Free)
United Kingdom
+44 808 196 4551 (Toll Free)
Canada
+1 888 605 7930 (Toll Free)
Australia
+61 1300 986 386 (Toll Free)
EdgeOne hotline
+852 300 80699
More local hotlines coming soon