1C:DN > Forum > 1C:Enterprise Platform > 1C:Enterprise – Business applications platform > "Getting data from multiple sources is not allowed" Error


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Bahrom
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Nov 21, 2025 07:44 PM
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I was creating a report in which I have to join 2 tables, "PersonZkTecoId" and "dbo_ZkTecoAttendance". in a query.

See the attached files, please.

What is the fix to this error?

Edited: Bahrom - Nov 21, 2025 05:46 PM
 
Aleksandr Biryukov
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Nov 26, 2025 08:53 PM
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Hello Bahrom,

this is a system limitation. A single query can use only one data source. It is not possible to use multiple sources simultaneously — for example, an external data source and data from 1C at the same time.
 
Bahrom
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Nov 28, 2025 07:36 AM
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Thank you Alexandr, After some research I came to the same conclusion either.

I found out following

Quote
In the 1C:Enterprise platform, there is a restriction that prevents simultaneously retrieving data from the main database table and an external data source table in a single query. This means that directly joining (JOIN) data from different sources within one 1C query is impossible.

Reasons and Limitations

Architectural Restriction: The 1C platform processes queries to external data sources differently than its internal tables. It cannot perform join operations (such as a LEFT JOIN) at the DBMS level when tables from different databases are involved.

Use of Temporary Tables: The use of temporary tables is also not permitted when working directly with external data sources in the same query that retrieves data from the main database.
 
Aleksandr Biryukov
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Nov 28, 2025 10:48 AM
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Yes, the whole point is that when you use an external data source, the query is physically executed on the source side, whether it’s an MS SQL Server or an Excel file. And of course, in this situation the 1C engine cannot join two tables if they are physically located in different places...

This also leads to a limitation on creating temporary tables — we cannot create a temporary table, for example, while reading data from a text file.
 
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