c# - SQL/C# : DataTable to stored procedure (INSERT from user-defined table type) - Converting error

Question

我正在尝试将我的 DataTable 传递给存储过程。 DataTable 包含 Excel 工作表的内容。 Excel 工作表有两个空列，五个是文本，五个是小数。空列是 OppdragsMVAkode 和 OppdragsgebyrMVAkode。

如果我运行我的应用程序，我会得到这个异常:

System.ArgumentException: Input string was not in a correct format. Couldn't store <> in OppdragsMVAkode Column. Expected type is Decimal.

如果我添加一个临时号码，我会得到这个异常:

System.Data.SqlClient.SqlException: Error converting data type nvarchar to numeric.

我不明白为什么要将它作为字符串读取。

我的存储过程(spGetTrips):

ALTER PROCEDURE [dbo].[spGetTrips]
    @trips udtTripsPerMonth readonly
    
AS
BEGIN
    INSERT INTO tblTripsPerMonth
        SELECT 
        [KjøretøyID], 
        SUBSTRING([År], 7, 4), 
        SUBSTRING([Måned], 4, 2), 
        [Betaling (brutto)], 
        [Betaling (netto)], 
        [Bestillingsgebyr (netto)], 
        [Betalingsgebyr (netto)], 
        [OppdragsMVAkode], 
        CONCAT(LøyvehaverFakturaID, + 'UF-' + SUBSTRING([År], 9, 2) + SUBSTRING([Måned], 4, 2)), 
        [Oppdragsgebyr (netto)], 
        [OppdragsgebyrMVAkode], 
        CONCAT([RidelRegionFakturaID], + 'UF-' + SUBSTRING([År], 9, 2) + SUBSTRING([Måned], 4, 2))
    FROM @trips

    UPDATE tblTripsPerMonth
    SET [OppdragsMVAkode] = (
        SELECT [ID]
        FROM [tblMVAkoder]
        WHERE [ID] = 'MVAkode2'
        );

    UPDATE tblTripsPerMonth
    SET [OppdragsgebyrMVAkode] = (
        SELECT [ID]
        FROM [tblMVAkoder]
        WHERE [ID] = 'MVAkode5'
        );
END

正如您在上面看到的，我在存储过程中使用 UPDATE 子句设置两个空列的值。无论它们在 Excel 工作表中为空，还是具有一些初步值，然后被覆盖，我都不关心 - 我只是希望它能正常工作。

这是我的用户定义表类型 (udtTripsPerMonth):

CREATE TYPE [dbo].[udtTripsPerMonth] AS TABLE(
    [KjøretøyID] [nvarchar](50) NULL,
    [År] [nvarchar](50) NULL,
    [Måned] [nvarchar](50) NULL,
    [Betaling (brutto)] [decimal](10, 2) NULL,
    [Betaling (netto)] [decimal](10, 2) NULL,
    [Bestillingsgebyr (netto)] [decimal](10, 2) NULL,
    [Betalingsgebyr (netto)] [decimal](10, 2) NULL,
    [OppdragsMVAkode] [decimal](10, 2) NULL,
    [LøyvehaverFakturaID] [nvarchar](50) NULL,
    [Oppdragsgebyr (netto)] [decimal](10, 2) NULL,
    [OppdragsgebyrMVAkode] [decimal](10, 2) NULL,
    [RidelRegionFakturaID] [nvarchar](50) NULL
)
GO

还有我的表(tblTripsPerMonth):

CREATE TABLE [dbo].[tblTripsPerMonth](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [KjøretøyID] [nvarchar](50) NULL,
    [År] [nvarchar](50) NULL,
    [Måned] [nvarchar](50) NULL,
    [Betaling (brutto)] [decimal](10, 2) NULL,
    [Betaling (netto)] [decimal](10, 2) NULL,
    [Bestillingsgebyr (netto)] [decimal](10, 2) NULL,
    [Betalingsgebyr (netto)] [decimal](10, 2) NULL,
    [OppdragsMVAkode] [decimal](10, 2) NULL,
    [LøyvehaverFakturaID] [nvarchar](50) NULL,
    [Oppdragsgebyr (netto)] [decimal](10, 2) NULL,
    [OppdragsgebyrMVAkode] [decimal](10, 2) NULL,
    [RidelRegionFakturaID] [nvarchar](50) NULL,
PRIMARY KEY CLUSTERED 
(
    [ID] ASC
)WITH (STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO

我在 UPDATE 子句 (tblMVAkoder) 中引用的另一个表:

CREATE TABLE [dbo].[tblMVAkoder](
    [ID] [nvarchar](50) NOT NULL,
    [Startdato] [date] NULL,
    [Sluttdato] [date] NULL,
    [MVAsats] [decimal](10, 2) NULL,
PRIMARY KEY CLUSTERED 
(
    [ID] ASC
)WITH (STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO

这是我的 C# 代码(Excel 到 DataTable):

private void btnExport_Click(object sender, RoutedEventArgs e) {

    OpenFileDialog of = new();
    of.Filter = "Excel Files | *.xlsx;";
    of.Title = "Importer Excel fil.";

    if (of.ShowDialog() == true) {

        dgPaidTrip.ItemsSource = ImportExceltoDataTable(of.FileName).DefaultView;
        btnClearForm.IsEnabled = true;
    }

    using (SqlConnection con = new(ConnectionString.connectionString))
    using (var cmd = new SqlCommand("spGetTrips", con) { CommandType = CommandType.StoredProcedure }) {

        con.Open();
        DataTable dt = ImportExceltoDataTable(of.FileName);
        cmd.Parameters.Add(new SqlParameter("@trips", dt));
        cmd.ExecuteNonQuery();
    }
}

public static DataTable ImportExceltoDataTable(string filePath) {

    using (XLWorkbook wb = new(filePath)) {

        IXLWorksheet ws = wb.Worksheet(1);
        int tl_Row = ws.FirstCellUsed().Address.RowNumber;
        int tl_Col = ws.FirstCellUsed().Address.ColumnNumber;
        int br_Row = ws.LastCellUsed().Address.RowNumber;
        int br_Col = ws.LastCellUsed().Address.ColumnNumber;

        DataTable dt = new();

        dt.Columns.Add("KjøretøyID", typeof(string));
        dt.Columns.Add("År", typeof(string));
        dt.Columns.Add("Måned", typeof(string));
        dt.Columns.Add("Betaling (brutto)", typeof(decimal));
        dt.Columns.Add("Betaling (netto)", typeof(decimal));
        dt.Columns.Add("Bestillingsgebyr (netto)", typeof(decimal));
        dt.Columns.Add("Betalingsgebyr (netto)", typeof(decimal));
        dt.Columns.Add("OppdragsMVAkode", typeof(decimal));
        dt.Columns.Add("LøyvehaverFakturaID", typeof(string));
        dt.Columns.Add("Oppdragsgebyr (netto)", typeof(decimal));
        dt.Columns.Add("OppdragsgebyrMVAkode", typeof(decimal));
        dt.Columns.Add("RidelRegionFakturaID", typeof(string));

        IXLRow currentRow;
    
        for (int dtRow = 0; dtRow < br_Row - tl_Row; dtRow++) {

            currentRow = ws.Row(tl_Row + dtRow + 1);
            dt.Rows.Add();

            for (int dtCol = 0; dtCol < br_Col - tl_Col + 1; dtCol++) {

                dt.Rows[dtRow][dtCol] = currentRow.Cell(tl_Col + dtCol).Value;
            }
        }

        return dt;
    }
}

据我所知，我的所有列类型及其顺序都匹配。我将所有类型更改为 nvarchar，并且代码“有效”。但是比我聪明的人告诉我，伪造列类型不是一个好主意。

我错过了什么？

Answer 1

要传递空值，您需要将列值设置为 DBNull.Value。您可以像这样设置 DBNull

dt.Rows[dtRow][dtCol] = currentRow.Cell(tl_Col + dtCol).Value ?? (object)DBNull.Value;

您还必须设置 SqlDBType TypeName 和 Direction 属性

cmd.Parameters.Add(
    new SqlParameter("@trips", SqlDBType.Structured)
    {
        TypeName = "dbo.udtTripsPerMonth",
        Direction = ParameterDirection.Input,
        Value = dt
    });