CREATE TABLE SupplierQuote
(
supplierQuoteID int identity (3504,2) CONSTRAINT supquoteid_pk PRIMARY KEY,PONumber int identity (9553,20) NOT NULL
.
.
.
CONSTRAINT ponumber_uq UNIQUE(PONumber)
);

以上ddl产生错误：

Msg 2744,Level 16,State 2,Line 1
Multiple identity columns specified
for table ‘SupplierQuote’. Only one
identity column per table is allowed.

我该如何解决？我想要PONumber自动递增.