Change Capture阶段异常报错求助：字段不可同时为键与值

Hey there, let's break down why you're hitting this error and how to fix it quickly.

What's causing the error? #

When you set the Change Capture stage to Explicit Keys, All Values mode, the stage has two distinct roles:

1. Use your selected Change Keys to match records between the before/after datasets.
2. Compare all non-Key fields (values) to detect changes.

The error pops up because one or more of your Key fields is also being treated as a Value field for comparison. This usually happens when:

• You didn't add the Key fields to the "Excluded Values" list (since All Values includes every field not explicitly excluded)
• Or, in the column list, you accidentally checked both the Key and Value flags for the same field

Step-by-step fix #

1. Open your Change Capture stage's properties and navigate to the column mapping section.
2. For every field you marked as a Change Key:
   • Either add it to the Excluded Values list (so it's excluded from value comparison checks)
   • Or, if there's a Value checkbox next to the field, uncheck it to remove it from the value comparison set
3. Double-check your Change Mode setting: Explicit Keys, All Values is correct for your use case (since you want to use specific keys and compare all other fields)
4. Save the stage settings and re-run your job.

Quick sanity check #

Remember: Change Keys are only for matching records across datasets—you don't need to compare their values unless your business logic specifically requires it (and in that case, you'd need to adjust your change mode or setup). The All Values mode is designed to compare everything except your keys, so excluding them from value comparisons is the right move here.

内容的提问来源于stack exchange，提问作者Jason