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Anonymous
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MySQL SCD Example in Components Guide

Good morning,
I'm using Talend Open Studio for Big Data, version 5.4.
I recreated the MySQL SCD example on p. 502 of the Components Guide, using my own data extract as a source. When I run it, I get the following error:
"Incorrect table definition. There can only be one auto column and it must be defined as a key"
The SCD configuration and schema are below. I didn't find this issue elsewhere in the Help Center.
Has anyone else encountered this? Is there something wrong with how I followed the example?

Thanks,
Mitch

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15 Replies
Anonymous
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Author

Hi,
Have you read TalendHelpCenter:tMysqlSCD with the section of "SCD management methodologies".
Best regards
Sabrina
Anonymous
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Author

Hi Sabrina,
Thank you for your prompt response.
I have reviewed that section of the Component Guide. The only discrepancy I noticed is that I did not map an input field for the surrogate key. The documentation implies that this is mandatory, but I set it to auto-increment (as in the example provided), so this shouldn't be an issue.
Is there some other factor that I'm missing, or am I misunderstanding the role of the input field?

Thanks,
Mitch
Anonymous
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Author

This is what the job looks like:
Anonymous
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Author

The tMysqlSCD_1 component also gives this error: "The schema from the input link "row2\" is different from the schema defined in the component"
The output schema for tLogRow_1 is the same as the input schema for tMysqlSCD_1. The difference appears to be in the SCD output schema, with the additional fields. Open Studio ought to recognize them, and not throw an error (this would have come up in the example case).
Anonymous
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Author

I synced the columns in the MysqlSCD component, removing the SCD-specific fields. The "row2 schema" issue disappeared.
When I ran it, every row was rejected. The Rejects output shows the errorCode field as null, and errorMessage as "Unknown column '' in 'where clause' - Line: 0" .
Anonymous
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Author

Instead of using my own data, I copied the data in the example, and followed the same configuration.
Again, every row was rejected. This time, however, errorMessage said "Unknown column 'status' in 'field list' - Line: 0". The status header and data were included in the reject output, so there were no nulls or confusion there.
Any assistance would be greatly appreciated. A successful SCD operation is critical for the functionality I need, and it's frustrating to see a simple example consistently fail.
Anonymous
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Author

One other thing I noticed:
Previously, the SCD fields in the MysqlSCD schema were highlighted in green. This time, they aren't.
The "row2 schema" issue is still there, though.
Anonymous
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Author

I scrapped my current attempt, and started over. After a schema correction in LogRow_2, the example ran successfully (both initial and update). w00t!
So now I'm trying to build my own, and I'm running into problems again. First it was "Unknown column 'scd_end' in 'where clause' - Line: 0" when scd_start and scd_end were added in the SCD component. After I included scd_version and scd_active, I got "Unknown column 'scd_version' in 'field list' - Line: 0".
Has anyone seen these errors, and figured out why?
Anonymous
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Author

*bump*