How To Fix DD_DBAL027 - Table &1: Alter type into table type &2 not allowed

DD_DBAL027 - Overview

• Message type: E = Error

• Message class: DD_DBAL - ABAP Dictionary, Data Base Abstraction Layer

• Message number: 027

• Message text: Table &1: Alter type into table type &2 not allowed

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message DD_DBAL027 - Table &1: Alter type into table type &2 not allowed ?

  The SAP error message DD_DBAL027 indicates that there is an issue with altering the type of a table in the database. Specifically, the error message states: "Table &1: Alter type into table type &2 not allowed." This typically occurs when there is an attempt to change the structure or type of a database table that is not permitted due to various constraints.
  
  Cause:
  
  Incompatible Data Types: The error often arises when there is an attempt to change the data type of a field in a table that is not compatible with the existing data or structure.
  Table Type Restrictions: Certain table types (like transparent tables, pooled tables, etc.) have restrictions on how they can be altered. For example, you cannot change a transparent table to a pooled table or vice versa.
  Foreign Key Constraints: If the table has foreign key relationships, altering the type may violate those constraints.
  Data Dictionary Restrictions: The SAP Data Dictionary