In Oracle 10g, how do I add a unique case-insensitive constraint on two varchar fields? For example, given the following records already in the table:
"Stephen", "Swensen"
"John", "Smith"
The following inserts would be invalid:
"stephen", "Swensen"
"John", "smith"
"stephen", "swensen"
But the following inserts would be valid:
"Stephen", "Smith"
"John", "Swensen"