SQL Server表主键值自动递增

Question

我正在使用一个简单的编码来使用实体框架在表格中添加记录，即

Transaction t = new Transaction();
t.CustomerID = 1; 
t.Date = DateTime.Now; 
t.Balance = 400;
t.Total = 500;
t.Paid = 100;

db.Transactions.Add(t);
db.SaveChanges();

但是在进入某些记录后，主键意外更改

请建议我一些建议谢谢。

编辑..

表格详情

CREATE TABLE [hassan].[Transaction]
(
    [TransactionId] [int] IDENTITY(1,1) NOT NULL,
    [Date] [datetime] NULL,
    [TransactionType] [nvarchar](20) NULL,
    [TransactionTypeID] [int] NULL,
    [Total] [numeric](18, 0) NULL,
    [Paid] [numeric](18, 0) NULL,
    [Balance] [numeric](18, 0) NULL,
    [Note] [nvarchar](50) NULL,
    [CustomerID] [int] NULL,
    [UserID] [int] NULL,
    [BranchID] [int] NULL,
    [Referance] [nvarchar](20) NULL,
    [SupplierID] [int] NULL,

    CONSTRAINT [PK_Transaction_1] 
     PRIMARY KEY CLUSTERED ([TransactionId] ASC)
          WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]