The name appears in the select list or WHERE clause of this query but is not defined in a table and does not appear as a statement local variable (SLV) definition. Check that the column name or SLV name and the names of the selected tables are spelled as you intended.
If all names are spelled correctly, you are not using the right tables, the database has been changed, or you have not defined the SLV. If the name not found is a reference to a column, that column might have been renamed or dropped. If the name not found represents an SLV and you defined the SLV in the statement, make sure that the SLV definition appears before all other references to that SLV name.
This error message can also appear during the execution of an ALTER TABLE statement when the engine tries to update views that depend on the table.