How To Fix MC802 - Union &: number of columns is not correct

SAP Error Message - Details

• Message type: E = Error

• Message class: MC - Aggregate: views, matchcodes, lock objects

• Message number: 802

• Message text: Union &: number of columns is not correct

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message MC802 - Union &: number of columns is not correct ?

  The SAP error message MC802, which states "Union &: number of columns is not correct," typically occurs in the context of SAP BW (Business Warehouse) or SAP BI (Business Intelligence) when there is an issue with the structure of a query or a data model that involves a union operation. This error indicates that the number of columns in the datasets being combined does not match, which is a requirement for union operations.
  
  Cause:
  
  
  Mismatched Column Count: The most common cause of this error is that the datasets being combined in the union operation have a different number of columns. For a union to work, all datasets must have the same number of columns and compatible data types.
  
  
  Incorrect Query Design: If you are designing a query that involves multiple InfoProviders or queries, the structure of these InfoProviders or queries may not align properly.
  
  
  Data Source Changes: If there have been changes to the