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The column names of a table must differ from each other. Base tables without user-defined key columns and named result tables contain the implicitly created column SYSKEY.
Named result tables with columns, which have not been explicitly named and which do not inherit a column name from the underlying base table, implicitly get the column name "EXPRESSION_". "_" stands for a positive integer.
A column must not be specified more than once in an INSERT or UPDATE statement or in a sequence of key specifications.
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Use different column names.
In a CREATE VIEW or QUERY statement, uniqueness of the column names can be achieved by reference name specifications in the selected columns. In a <CREATE VIEW statement>, uniqueness can also be obtained by alias names specifications.
Correct the repeated specification of the same column.