Cannot convert datatype nvarchar to numeric

Question

I import data from from an Excel file into a SQL Server database with the following query. The Excel file has all values as string types ( ' before every cells).

I get this error when I import it."Cannot convert datatype nvarchar to numeric"

If I remove the two columns SalePrice and Price2 from importing, then the import is successful.

The datatypes of my table is

CREATE TYPE [dbo].[InventoryType] AS TABLE
(
   [LocalSKU] [varchar](200) NOT NULL,
   [ItemName] [varchar](200) NULL,
   [QOH] [int] NULL,
   [Price] [decimal](19, 4) NULL,
   [Discontinued] [bit] NULL,
   [Barcode] [varchar](25) NULL,
   [Integer2] [int] NULL,
   [Integer3] [int] NULL,
   [SalePrice] [decimal](19, 4) NULL,
   [SaleOn] [bit] NULL,
   [Price2] [decimal](19, 4) NULL
)
GO

The query I am using is:

SqlCommand sqlcmd = new SqlCommand
   (@"MERGE Inventory AS target
      USING (SELECT
                LocalSKU, ItemName, QOH, Price, Discontinued, 
                Barcode, Integer2, Integer3, SalePrice, SaleOn, Price2 
             FROM @source) AS Source ON (Source.LocalSKU = target.LocalSKU)
      WHEN MATCHED THEN
         UPDATE 
           SET ItemName = source.ItemName,
               Price = source.Price,
               Discontinued = source.Discontinued,
               Barcode = source.Barcode,
               Integer2 = source.Integer2,
               Integer3 = source.QOH,
               SalePrice = source.SalePrice,
               SaleOn = source.SaleOn,
               Price2 = source.Price2;", sqlconn);

SqlParameter param;
param = sqlcmd.Parameters.AddWithValue("@source", dr);
param.SqlDbType = SqlDbType.Structured;
param.TypeName = "dbo.InventoryType";

sqlconn.Open();
sqlcmd.ExecuteNonQuery();
sqlconn.Close();

Answer 1

One thing to keep in mind is that you may have some invalid data in the given column that's throwing the error(s). For example if you have a Numeric column and have letters or inproperly formatted numeric values, this error will be thrown. Check for values in your cells that aren't correct first. This includes trailing or leading spaces as well.