How To Fix DA421 - Changing the type deletes the data from the original table

DA421 - Overview

• Message type: E = Error

• Message class: DA - Dictionary: Compare, distribution, timer, instantiation

• Message number: 421

• Message text: Changing the type deletes the data from the original table

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message DA421 - Changing the type deletes the data from the original table ?

  The SAP error message DA421, which states "Changing the type deletes the data from the original table," typically occurs when you attempt to change the data type of a field in a database table that has existing data. This can lead to data loss if the new data type is incompatible with the existing data.
  
  Cause:
  
  Data Type Incompatibility: The new data type you are trying to assign to a field may not be compatible with the existing data. For example, changing a field from a character type to a numeric type could lead to loss of data.
  Data Structure Changes: Modifying the structure of a table (like changing a field type) can lead to inconsistencies if not handled properly, especially if the table is already populated with data.
  Database Constraints: Certain constraints or relationships in the database may prevent the change from being made without data loss.
  
  
  Solution:
  
  Backup Data: Before making any changes, ensure