A.对变量使用 NEWID 函数下面的示例使用 NEWID 对声明为 uniqueidentifier 数据类型的变量赋值。在测试该值前，将先打印 uniqueidentifier 数据类型变量的值。-- Creating a local variable with DECLARE/SET syntax.DECLARE @myid uniqueidentifierSET @myid = NEWID()PRINT 'Value of @myid is: '+ CONVERT(varchar(255), @myid)下面是结果集：Value of @myid is: 6F9619FF-8B86-D011-B42D-00C04FC964FF说明 对于每台计算机，由 NEWID 返回的值不同。所显示的数字仅起解释说明的作用。B.在 CREATE TABLE 语句中使用 NEWID下面的示例创建具有 uniqueidentifier 数据类型的 cust 表，并使用 NEWID 将默认值填充到表中。为 NEWID() 赋默认值时，每个新行和现有行均具有 cust_id 列的唯一值。 -- Creating a table using NEWID for uniqueidentifier data type. CREATE TABLE cust( cust_id uniqueidentifier NOT NULL DEFAULT newid(), company varchar(30) NOT NULL, contact_name varchar(60) NOT NULL, address varchar(30) NOT NULL, city varchar(30) NOT NULL, state_province varchar(10) NULL, postal_code varchar(10) NOT NULL, country varchar(20) NOT NULL, telephone varchar(15) NOT NULL, fax varchar(15) NULL)GO-- Inserting data into cust table.INSERT cust(cust_id, company, contact_name, address, city, state_province, postal_code, country, telephone, fax)VALUES(newid(), 'Wartian Herkku', 'Pirkko Koskitalo', 'Torikatu 38', 'Oulu', NULL, '90110', 'Finland', '981-443655', '981-443655')INSERT cust(cust_id, company, contact_name, address, city, state_province,postal_code, country, telephone, fax)VALUES (newid(), 'Wellington Importadora', 'Paula Parente', 'Rua do Mercado, 12', 'Resende', 'SP', '08737-363', 'Brazil', '(14) 555-8122', '')INSERT cust(cust_id, company, contact_name, address, city, state_province, postal_code, country, telephone, fax)VALUES(newid(), 'Cactus Comidas para Ilevar', 'Patricio Simpson', 'Cerrito 333', 'Buenos Aires', NULL, '1010', 'Argentina', '(1) 135-5555', '(1) 135-4892')INSERT cust(cust_id, company, contact_name, address, city, state_province, postal_code, country, telephone, fax)VALUES (newid(), 'Ernst Handel', 'Roland Mendel', 'Kirchgasse 6', 'Graz', NULL, '8010', 'Austria', '7675-3425', '7675-3426')INSERT cust(cust_id, company, contact_name, address, city, state_province, postal_code, country, telephone, fax)VALUES (newid(), 'Maison Dewey', 'Catherine Dewey', 'Rue Joseph-Bens 532', 'Bruxelles', NULL, 'B-1180', 'Belgium', '(02) 201 24 67', '(02) 201 24 68')GOC. 使用 uniqueidentifier 和变量赋值下面的示例声明局部变量 @myid 为 uniqueidentifier 数据类型。然后使用 SET 语句为该变量赋值。DECLARE @myid uniqueidentifier SET @myid = 'A972C577-DFB0-064E-1189-0154C99310DAAC12'GO
