在没有存储过程的情况下在 ADO.Net 中获取输出值

Question

我正在将 ADODB 应用程序转换为 ADO.Net，其中包含一个插入新行并返回自动增量值的命令，如下所示：-

INSERT INTO [MyDB].[dbo].[MyTable] (COLUMN1, COLUMN2) OUTPUT inserted.ID_PRIMARY
                      VALUES ('This', 'That')

然后可以获取 OUTPUT 值并离开。但是当我尝试使用 ADO.Net 时，就像这样：-

command_string = (as above)
Dim insert_command   As SqlCommand     = New SqlCommand(command_string, database_connection)
Dim output_parameter As SqlParameter   = New SqlParameter("@inserted.ID_PRIMARY", SqlDbType.Int)
Dim transaction      As SqlTransaction = database_connection.BeginTransaction(System.Data.IsolationLevel.Serializable)
insert_command.Transaction = transaction
output_parameter.Direction = ParameterDirection.Output
insert_command.Parameters.Add(output_parameter)
insert_command.ExecuteNonQuery()
transaction.Commit

返回错误：-

SqlException (0x80131904) '.' 附近的语法不正确

我很感激我可以使用存储过程来执行插入并检索返回值，正如here 所解释的那样，但我想知道是否有任何方法可以在没有存储过程的情况下完成？还是我忽略了一些微不足道的错误？

Answer 1

OUTPUT Inserted.ID_PRIMARY 中新插入的ID 将是语句返回的数据集。您需要使用 ExecuteReader 方法来读取返回的值：

' setup as above - except you don't need the "output_parameter"
Dim reader As SqlDataReader = insert_command.ExecuteReader()

While reader.Read()
    ' get your newly inserted ID's here as returned dataset
    Dim newlyInsertedID As Integer = reader.GetInt32(0)

    ' if you insert multiple rows at once, you might need store those ID's 
    ' that you fetch back one by one into a list or something
End While

Answer 2

您可以利用 SQL Server 可以在一个批处理中发出两个 sql 命令这一事实。并使用 T-SQL 函数SELECT SCOPE_IDENTITY 查找添加到当前作用域的最新标识值

Dim sqlText = "INSERT INTO [MyDB].[dbo].[MyTable] (COLUMN1, COLUMN2) " & _
              "VALUES ('This', 'That'); SELECT SCOPE_IDENTITY()"
Dim insert_command = New SqlCommand(sqlText, database_connection)
insert_command.Transaction = transaction
Dim result = Convert.ToInt32(insert_command.ExecuteScalar())
transaction.Commit

否则，如果您想使用您的语法，则删除输出参数

Dim sqlText = "INSERT INTO [MyDB].[dbo].[MyTable] (COLUMN1, COLUMN2) " & _ 
              "OUTPUT inserted.ID_PRIMARY  VALUES ('This', 'That')"
Dim insert_command  = New SqlCommand(sqlText, database_connection)
insert_command.Transaction = transaction
Dim result = Convert.ToInt32(insert_command.ExecuteScalar())
transaction.Commit

但和以前一样，使用 ExecuteScalar 来检索查询返回的第一行/第一列的值

Answer 3

语法错误已通过将 SQL 更改为：-

INSERT INTO [MyDB].[dbo].[MyTable] (COLUMN1, COLUMN2)
    OUTPUT inserted.ID_PRIMARY As ID_PRIMARY
        VALUES ('This', 'That')

并像这样设置参数：-

Dim output_parameter As SqlParameter = New SqlParameter("@ID_PRIMARY", SqlDbType.Int)

Answer 4

试试下面的代码：

/****** Object:  Table [dbo].[Pedidos]    Script Date: 03/01/2015 16:48:17 ******/
SET ANSI_NULLS ON
GO


SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Pedidos](
[PedidoID] [int] IDENTITY(1,1) NOT NULL,
[Data] [date] NOT NULL,
[clienteID] [int] NOT NULL,
 CONSTRAINT [PK_Pedidos] PRIMARY KEY CLUSTERED 
(
[PedidoID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY =     OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

ALTER TABLE [dbo].[Pedidos]  WITH CHECK ADD  CONSTRAINT     [FK_Pedidos_Clientes] FOREIGN KEY([clienteID])
REFERENCES [dbo].[Clientes] ([clienteID])
GO

ALTER TABLE [dbo].[Pedidos] CHECK CONSTRAINT [FK_Pedidos_Clientes]
GO

使用 Dim Identity As Integer 或声明 PUBLIC 返回插入记录的标识自动递增字段PedidoID的值。

    Dim connection As SqlConnection = databaseDB.GetConnection
    Dim insertStatement As String _
        = "INSERT [dbo].[Pedidos] " _
        & "([Data], [clienteID]) " _
        & "VALUES (@Data, @clienteID) SELECT @PedidoID = SCOPE_IDENTITY()" 'SELECT SCOPE_IDENTITY() AS 'Identity
    Dim insertCommand As New SqlCommand(insertStatement, connection)
    insertCommand.CommandType = CommandType.Text
    insertCommand.Parameters.AddWithValue("@Data", dbo_pedidos.Data)
    insertCommand.Parameters.AddWithValue("@clienteID", dbo_pedidos.clienteID)
    ' Inclui o SqlParameter para retornar o novo valor identity
    ' Define o ParameterDirection como Output.(Saida)
    insertCommand.Parameters.Add("@PedidoID", SqlDbType.Int, 0, "PedidoID")
    insertCommand.Parameters("@PedidoID").Direction = ParameterDirection.Output

    Try
        connection.Open()
        Dim count As Integer = insertCommand.ExecuteNonQuery()
        If count > 0 Then
            Identity = insertCommand.Parameters("@PedidoID").Value
            Return True
        Else
            Return False
        End If
    Catch ex As SqlException
        Throw ex
    Finally
        connection.Close()
    End Try