Is an identifier for the common table expression. The expr_name must be unique among other common table expression names defined in the same WITH common_table_expression clause, but expr_name can be the same as the name of a base table or view. Any reference to expr_name in the query uses the common table expression and not the base object.

Specifies a column name in the common table expression. Duplicate names within a single CTE definition are not allowed. The number of column names specified must match the number of columns in the result set of the CTE_query_def. The list of column names is optional only if distinct names for all resulting columns are supplied in the query expression.

Specifies a SELECT statement whose result set populates the common table expression. The SELECT statement for CTE_query_def must meet the same requirements as for creating a view, except a CTE cannot define another CTE.

If more than one CTE_query_def is defined, the queries must be joined by either UNION or UNION ALL.