Restrictions on Long Nvarchar Columns
The following restrictions apply to long nvarchar columns:
• They cannot be part of a table key.
• They do not declare a length.
• They cannot be part of a secondary index.
• They cannot be used in the order by group, or by clause in a select statement.
• They cannot have query optimization statistics. For details about query optimization statistics, see the discussion of the optimizedb utility in the Command Reference Guide.
• The following string functions do not work with long nvarchar columns:
– Locate
– Pad
– Shift
– Squeeze
– Trim
– Notrim
– Charextract
• These columns cannot be directly compared to other string data types. To compare a long nvarchar column to another string data type, apply a coercion function.
• A string literal of more than 1000 characters cannot be assigned to a long nvarchar column. Details about assigning long strings to these columns are found in the description of data handlers in the Embedded SQL Companion Guide or the OpenAPI User Guide.