[OPENJPA-1841] Allow DBDictionary to optimize IS [NOT] NULL SQL for specific data types.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.1.0
• Fix Version/s: 2.1.0
• Component/s: jdbc
• Assignee: Michael Dick
• Reporter: Michael Dick
• Created: 18/Oct/10 21:43
• Updated: 19/Oct/10 18:38
• Resolved: 19/Oct/10 18:38

Description

Some databases do not support IS [NOT] NULL on all datatypes.

For example Sybase does not allow it's clob / blob types (TEXT and IMAGE respectively) to be used with the IS NULL and IS NOT NULL clauses. The datalength() function to determine if the column has any data instead of the generic IS [NOT] NULL clause.

Oracle has a similar restriction with BLOB / CLOB types.