sqlserver如何判断某字段做唯一索引，而且是单独

IF (
SELECT COUNT(*) FROM sys.index_columns 
INNER JOIN sys.indexes ON indexes.index_id = index_columns.index_id AND indexes.object_id = index_columns.object_id
INNER JOIN sys.columns ON columns.column_id = index_columns.column_id AND columns.object_id = indexes.object_id
WHERE indexes.object_id=OBJECT_ID(N'dbo.tblEnh_SuppQuo', N'U')  AND indexes.is_unique=1 AND columns.name =N'InternalQuoNo'
)=1
BEGIN
	SELECT 1
END 

或者

IF (
SELECT COUNT(*) FROM sys.index_columns 
INNER JOIN sys.indexes ON indexes.index_id = index_columns.index_id AND indexes.object_id = index_columns.object_id
INNER JOIN sys.columns ON columns.column_id = index_columns.column_id AND columns.object_id = indexes.object_id
INNER JOIN sys.objects ON objects.object_id = indexes.object_id 
WHERE objects.name=N'tblEnh_SuppQuo' AND objects.schema_id=1 AND objects.type=N'U' and  indexes.is_unique=1 AND columns.name =N'InternalQuoNo'
)=1
BEGIN
	SELECT 1
END