c# - 缺少表定义的 SQL 条件

Question

我想知道当这些字段 doctorId、dateApt、hourApt 具有相同的日期和小时以及 doctorId 时，我的表定义中不允许创建新行的条件是什么。

ex:  aptId  ClientId  doctorId  dateApt     TimeApt  IsAvaiable
     1      Null      1         2014/01/29  09:00    True
     2      Null      1         2014/01/29  09:00    True    <== not allowing this
     3      Null      1         2014/01/29  10:00    True    <== ok bc not same hour and date
     4      Null      2         2014/01/29  09:00    True    <== ok not same doctorId

这是表定义。

CREATE TABLE [dbo].[Appointement] (
    [aptId]       INT      IDENTITY (1, 1) NOT NULL,
    [clientId]    INT      NULL,
    [doctorId]    INT      NOT NULL,
    [dateApt]     DATE     NOT NULL,
    [hourApt]     TIME (7) NOT NULL,
    [IsAvailable] BIT      NULL,
    PRIMARY KEY CLUSTERED ([rdvId] ASC),
    CONSTRAINT [fk_doctorID] FOREIGN KEY ([doctorId]) REFERENCES [dbo].[Doctor] ([Id]),
    CONSTRAINT [fk_clientID] FOREIGN KEY ([clientId]) REFERENCES [dbo].[User] ([Id_user])
);

谢谢

Answer 1

在这些列上添加唯一约束:

ALTER TABLE dbo.Appointement
  ADD CONSTRAINT uAppt UNIQUE (doctorId, dateApt, hourAp)

或者在创建表时添加:

CREATE TABLE [dbo].[Appointement] (
     [aptId]       INT      IDENTITY (1, 1) NOT NULL,
     [clientId]    INT      NULL,
     [doctorId]   INT      NOT NULL,
     [dateApt]   DATE     NOT NULL,
     [hourApt]  TIME (7) NOT NULL,
     [IsAvailable] BIT      NULL,
     PRIMARY KEY CLUSTERED ([rdvId] ASC),
     CONSTRAINT [fk_doctorID] FOREIGN KEY ([doctorId]) REFERENCES [dbo].[Doctor] ([Id]),
     CONSTRAINT [fk_clientID] FOREIGN KEY ([clientId]) REFERENCES [dbo].[User] ([Id_user]),
     CONSTRAINT uAppt UNIQUE (doctorId, dateApt, hourAp)
 );