Question

public static void WriteData(string colName,string data)
{
    using (OleDbConnection cn = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Constants.FileName + ";Extended Properties=\"Excel 8.0;HDR=NO;IMEX=3;READONLY=FALSE\""))
    {
        // string query = String.Format("INSERT INTO  [DataSet$]({0}) VALUES ({1})",colName, data);

        string query = String.Format("INSERT INTO  [DataSet$]({0}) VALUES ({1})", colName, data);
        cn.Open();
        OleDbCommand cmd = new OleDbCommand(query, cn);
        cmd.Parameters.AddWithValue("@colName", colName);
        cmd.Parameters.AddWithValue("@data", data);

        cmd.ExecuteNonQuery();
        cn.Close();
        cn.Dispose();
    }
}

Answer 1

您要做的是混合动态查询生成和查询参数。您不能使用命令参数来填充查询中的列名称。参数仅用于将值传递给查询。

所以你需要做的是，只使用string.Format在查询中放置列名，并仅使用命令参数将数据传递给查询。

public void WriteData(string colName, string data)
{
    using (OleDbConnection cn = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Constants.FileName + ";Extended Properties=\"Excel 8.0;HDR=NO;IMEX=3;READONLY=FALSE\""))
    {
        string query = string.Format("INSERT INTO [DataSet$] ({0}) VALUES (@data)", colName);
        // The query variable will have following value assuming colName=token
        //INSERT INTO [DataSet$] (token) VALUES (@data)
        cn.Open();
        //Now use OleDbCommand to pass value of @data to the query.
        OleDbCommand cmd = new OleDbCommand(query, cn);
        cmd.Parameters.AddWithValue("@data", data);

        cmd.ExecuteNonQuery();
        cn.Close();
    }
}

这可以帮助您解决问题。

Answer 2

public static void UpdateData(string keyName,string colName,string data)
    {
        using (OleDbConnection connection = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Constants.FileName + ";Extended Properties=\"Excel 8.0;HDR=NO;IMEX=3;READONLY=FALSE\""))
        {
            // string query = String.Format("INSERT INTO  [DataSet$]({0}) VALUES ({1})",colName, data);

                connection.Open();
                string commandString = String.Format("UPDATE [DataSet$] SET colName ='{0}' WHERE keyName = '{1}'",@data,@keyName);
                OleDbCommand cmd = new OleDbCommand(commandString, connection);
            cmd.Parameters.AddWithValue("@data", data);
            cmd.Parameters.AddWithValue("@keyName", keyName);
            connection.Close();
                connection.Dispose();
            }
        }
    }

消息：System.Data.OleDb.OleDbException：查询表达式中的语法错误（缺少运算符）

2 个答案: