Task Parameter Examples

This page provides complete usage examples for task parameters in common business scenarios, including SQL task and Python task examples, plus a FAQ.

Scenario Examples

Scenario 1: Processing yesterday's partition data

Requirement: Process the previous day's order data every morning.

INSERT OVERWRITE TABLE order_summary PARTITION(dt='${yesterday}') SELECT order_id, SUM(amount) AS total_amount, COUNT(*) AS order_count FROM order_detail WHERE dt = '${yesterday}' GROUP BY order_id;

Parameter configuration: yesterday = $[yyyy-MM-dd, -1d]

If the task runs on 2023-09-22, ${yesterday} is substituted with 2023-09-21.

Scenario 2: Generating a monthly report (last month's data)

Requirement: Generate last month's sales report on the 1st of each month.

SELECT product_id, SUM(sales_amount) AS total_sales, COUNT(DISTINCT user_id) AS unique_users FROM sales_table WHERE dt BETWEEN '${last_month_start}' AND '${last_month_end}' GROUP BY product_id;

Parameter configuration:

  • last_month_start = first_day_of_month('yyyy-MM-dd', '-1mon')
  • last_month_end = last_day_of_month('yyyy-MM-dd', '-1mon')

If the task runs on 2023-09-01: last_month_start → 2023-08-01, last_month_end → 2023-08-31.

Scenario 3: Weekly report (last Monday through Sunday)

Requirement: Generate last week's user activity report every Monday.

SELECT DATE(login_time) AS login_date, COUNT(DISTINCT user_id) AS active_users FROM user_login_log WHERE dt BETWEEN '${last_week_monday}' AND '${last_week_sunday}' GROUP BY DATE(login_time) ORDER BY login_date;

Parameter configuration:

  • last_week_monday = first_day_of_week('yyyy-MM-dd', '-1w')
  • last_week_sunday = last_day_of_week('yyyy-MM-dd', '-1w')

If the task runs on 2023-09-25 (Monday): last_week_monday → 2023-09-18, last_week_sunday → 2023-09-24.

Scenario 4: Getting every Tuesday's data

Requirement: Periodically analyze Tuesday promotion performance.

SELECT promotion_id, SUM(sales_amount) AS tuesday_sales FROM sales_table WHERE dt = '${this_tuesday}' GROUP BY promotion_id;

Parameter configuration: this_tuesday = get_day_of_week('yyyy-MM-dd', 2)

  • Task runs on 2023-09-22 (Friday) → 2023-09-19 (this Tuesday)
  • Task runs on 2023-09-25 (Monday) → 2023-09-26 (this Tuesday)

Scenario 5: Timestamp range query (full-day data)

Requirement: Query order data from today 00:00:00 to tomorrow 00:00:00.

SELECT order_id, order_time, amount FROM orders WHERE order_timestamp >= ${today_start} AND order_timestamp < ${tomorrow_start};

Parameter configuration:

  • today_start = biz_timestamp()
  • tomorrow_start = biz_timestamp(1d)

If the task runs on 2023-09-22: today_start → 1695312000000, tomorrow_start → 1695398400000.

Scenario 6: Using parameters in a Python task

String-type parameters need quotes:

yesterday = '${yesterday}' task_name = '${task_name}'

Numeric-type parameters do not need quotes:

start_ts = ${start_ts} print(f"Processing date: {yesterday}") print(f"Start timestamp: {start_ts}") sql = f""" SELECT * FROM orders WHERE dt = '{yesterday}' AND create_time >= {start_ts} """

Parameter configuration:

  • yesterday = $[yyyy-MM-dd, -1d]
  • start_ts = biz_timestamp()
  • task_name = sys_task_name

FAQ

Q1: What is the difference between manual run and scheduled run parameters?

DimensionManual runScheduled run
Parameter sourceEntered manually in the dialogValues from the saved parameter configuration
ScopeThis run onlyEvery scheduled execution
Time referenceThe moment you click RunThe scheduled plan time
sys_task_* parametersNot supportedSupported
Use caseDebugging, validationAutomated production runs

Parameter values entered during a manual run are not saved to the parameter configuration.

Q2: How do I verify that my parameter configuration is correct?

Run the following in a SQL task to see the substituted result directly:

SELECT '${yesterday}' AS yesterday; -- Parameter config: yesterday = $[yyyy-MM-dd, -1d] -- If it returns yesterday's date, the configuration is correct

You can also check the execution log to view the actual SQL that ran and confirm the parameters were substituted correctly.

Q3: How do I handle end-of-month date offset issues?

$[yyyy-MM-dd, -1mon] can be ambiguous at month-end (e.g., January 31 minus 1 month). When you specifically need the last day of the previous month, use last_day_of_month():

-- Recommended: explicitly get the last day of the previous month last_month_end = last_day_of_month('yyyy-MM-dd', '-1mon') -- Always returns the last day of the previous month, regardless of the current month's length

Q4: How do I debug complex parameter expressions?

Validate step by step, from simple to complex:

-- Step 1: verify the basic format SELECT '${base_date}' AS base_date; -- base_date = $[yyyy-MM-dd] -- Step 2: add an offset SELECT '${offset_date}' AS offset_date; -- offset_date = $[yyyy-MM-dd, -1mon] -- Step 3: add multiple offsets SELECT '${final_date}' AS final_date; -- final_date = $[yyyy-MM-dd, -1mon, -7d]

Q5: How do I modify an encrypted parameter?

  1. Open the parameter configuration and find the encrypted parameter.
  2. Uncheck "Encrypt value" — the value is displayed in plain text.
  3. Make your changes, then re-check "Encrypt value".

Encryption only affects how the value is displayed; it does not affect how the parameter is substituted at runtime.

Task Parameter Syntax Reference
Dynamic Table Tasks
Singdata © 2024 Singdata, Inc. All Rights Reserved.