默认约束导致错误

Question

我有以下 SQL 来创建表，但第一个 CONSTRAINT 中的“DEFAULT”给了我一个错误：“默认约束只能存在于 CREATE 或 ALTER TABLE 语句中的列级别。”

我以前从未使用过默认值，因此我通过互联网研究对此进行了一些调查，但没有任何东西可以帮助我解决错误，甚至没有向我真正解释过。

CREATE TABLE [RuleEngine].[NCCIImportHistory](
                [NCCIImportHistoryID] [int] IDENTITY(1,1) NOT NULL,
                [StartTime] [datetimeoffset](7) NOT NULL,
                [EndTime] [datetimeoffset](7) NOT NULL,
                [CreatedOn] [datetimeoffset](7) NOT NULL,
                [CreatedBy_UserID] [int] NOT NULL,
CONSTRAINT [DF_NCCIImportHistory_CreatedOn]  DEFAULT (getutcdate()) FOR [CreatedOn],
CONSTRAINT [FK_NCCIImportHistory_User_CreatedBy] FOREIGN KEY([CreatedBy_UserID]) REFERENCES [Security].[User] ([UserID]),
CONSTRAINT [PK_NCCIImportHistoryID] PRIMARY KEY CLUSTERED ([NCCIImportHistoryID] ASC) 
    WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]) ON [PRIMARY]

Answer 1

您没有指定您使用的数据库，但根据语法我认为它是 MS SQL Server。如果是这样，您可以将约束内联添加为列定义的一部分，如下所示：

[CreatedOn] [datetimeoffset](7) NOT NULL CONSTRAINT [DF_NCCIImportHistory_CreatedOn] DEFAULT (getutcdate()),

Answer 2

试试这个

CREATE TABLE [RuleEngine].[NCCIImportHistory]
    (
      [NCCIImportHistoryID] [INT] IDENTITY(1, 1)
                                  NOT NULL ,
      [StartTime] [DATETIMEOFFSET](7) NOT NULL ,
      [EndTime] [DATETIMEOFFSET](7) NOT NULL ,
      [CreatedOn] [DATETIMEOFFSET](7) NOT NULL CONSTRAINT [DF_NCCIImportHistory_CreatedOn] DEFAULT ( GETUTCDATE() ),
      [CreatedBy_UserID] [INT] NOT NULL ,
      CONSTRAINT [FK_NCCIImportHistory_User_CreatedBy] FOREIGN KEY ( [CreatedBy_UserID] ) REFERENCES [Security].[User] ( [UserID] ) ,
      CONSTRAINT [PK_NCCIImportHistoryID] PRIMARY KEY CLUSTERED
        ( [NCCIImportHistoryID] ASC )

        WITH ( PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,
               IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON,
               ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90 ) ON [PRIMARY]
    )
ON  [PRIMARY]

或先创建表，然后像这样的约束

CREATE TABLE [RuleEngine].[NCCIImportHistory]
    (
      [NCCIImportHistoryID] [INT] IDENTITY(1, 1) NOT NULL ,
      [StartTime] [DATETIMEOFFSET](7) NOT NULL ,
      [EndTime] [DATETIMEOFFSET](7) NOT NULL ,
      [CreatedOn] [DATETIMEOFFSET](7) NOT NULL,
      [CreatedBy_UserID] [INT] NOT NULL 
    )
ON  [PRIMARY]
GO


ALTER TABLE  [RuleEngine].[NCCIImportHistory] ADD CONSTRAINT [DF_NCCIImportHistory_CreatedOn] DEFAULT( GETUTCDATE() ) FOR [CreatedOn]
GO

ALTER TABLE  [RuleEngine].[NCCIImportHistory] ADD CONSTRAINT [FK_NCCIImportHistory_User_CreatedBy]  FOREIGN KEY ( [CreatedBy_UserID] ) REFERENCES [Security].[User] ( [UserID] )
GO

ALTER TABLE  [RuleEngine].[NCCIImportHistory] ADD CONSTRAINT [PK_NCCIImportHistoryID] PRIMARY KEY CLUSTERED( [NCCIImportHistoryID] ASC ) WITH ( PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,
               IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON,
               ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90 ) ON [PRIMARY]
GO