[Solved] Error encountered by mysql multi-table query [Err] 1052 – Column ‘user_id’ in field list is ambiguous

I encountered this error when doing a multi-table query in mysql

[Err] 1052 - Column 'user_id' in field list is ambiguous

Cause analysis: When a multi-table query is performed, a certain field is shared by two tables. If a certain field is placed in the middle of the select query content from without indicating that it is owned by this or that table, it will occur during query. If the reference is unknown, the above error will appear. As shown

Solution: This error can be solved as long as the field standard in the query is owned by that table.

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