cqzQK16D

1CREATE TABLE dbo.Customer
2(
3    RowId bigint IDENTITY(1,1) NOT NULL,
4    CustomerId guid NOT NULL,
5    Name varchar(255) NOT NULL,
6    CONSTRAINT PK_RowId PRIMARY KEY CLUSTERED([RowId] ASC)
7)
8create unique nonclustered index [UN_CustomerId] ON [dbo].[Customer] ([CustomerId] ASC) include (Name)
9create nonclustered index [UN_Name] ON [dbo].[Customer] ([Name] ASC) include (CustomerId)
10
11
12IF NOT EXISTS
13(
14    SELECT top 1 customerid
15    FROM dbo.Customer WITH (UPDLOCK, SERIALIZABLE) 
16    WHERE Name = @Name
17)
18BEGIN
19    INSERT INTO dbo.Customer(CustomerId, Name) VALUES (@CustomerId, @Name)
20    SELECT @CustomerId
21END
22ELSE
23BEGIN
24    SELECT CustomerId FROM dbo.Customer WHERE Name = @Name
25END