正在分析类型为的CSV文件

本文关键字：CSV 文件 类型 | 更新日期: 2023-09-27 18:22:34

我正在尝试解析CSV并从中构建一个DataTable。现在棘手的部分是，我想在构建数据表之前分配数据类型。例如，考虑以下CSV文件

Name,Age,Salary
A,30,1000
B,35,1500
C,40,2000

我希望在我正在构建的数据表中，Name存储为字符串，Age存储为Int，Salary存储为十进制。关于最好的方法有什么建议吗？

正在分析类型为的CSV文件

这里有一个简单的实现，它忽略了大多数错误检查和一些良好的编码实践：

namespace StackOverflowConsole
{
    using System;
    using System.IO;
    using System.Data;
    class Program
    {
        static void Main(string[] args)
        {
            var path = @"C:'temp'test.csv";
            CreateTestFile(path);
            var dataTable = new DataTable();
            dataTable.Columns.Add("Name", typeof(string));
            dataTable.Columns.Add("Age", typeof(int));
            dataTable.Columns.Add("Salary", typeof(decimal));
            // TODO: add checks, exception handling
            using (var reader = new StreamReader(path))
            {
                // reads all lines into a single string
                var lines = reader.ReadToEnd().Split(new char[] { ''n' });
                if (lines.Length > 0)
                {
                    // you may wanna skip the first line, if you're using a file header
                    foreach (string line in lines)
                    {
                        if (string.IsNullOrWhiteSpace(line))
                        {
                            continue;
                        }
                        // split the current line using the separator
                        var tokens = line.Trim().Split(new char[] { ',' });
                        // check your assumptions on the CSV contents
                        // ex: only process lines with the correct number of fields
                        if (tokens.Length == 3)
                        {
                            var person = new Person();
                            person.Name = tokens[0];
                            // a better implementation would use TryParse()
                            person.Age = Int32.Parse(tokens[1]);
                            person.Salary = Decimal.Parse(tokens[2]);
                            dataTable.Rows.Add(person.Name, person.Age, person.Salary);
                        }
                    }
                }
            }
        }
        private static void CreateTestFile(string path)
        {
            if (File.Exists(path))
            {
                File.Delete(path);
            }
            using (var writer = new StreamWriter(path))
            {
                writer.WriteLine("A,30,1000");
                writer.WriteLine("B,35,1500");
                writer.WriteLine("C,40,2000");
            }
        }
    }
    public class Person
    {
        public string Name;
        public int Age;
        public decimal Salary;
    }
}

试试这个：

将CSV文件保存在代码目录中

string path = Server.MapPath("emp.csv");
            string header = "Yes";
            string sql = string.Empty;
            DataTable dt = null;
            string fullpath = Path.GetDirectoryName(path);
            string fileName = Path.GetFileName(path);
            OleDbConnection connection = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fullpath + ";Extended Properties='"Text;HDR=" + header + "'"");
            OleDbDataAdapter da = new OleDbDataAdapter("select * from [" + fileName + "]", connection);
            dt = new DataTable();
            dt.Columns.Add("Name", typeof(string));
            dt.Columns.Add("Age", typeof(int));
            dt.Columns.Add("Salary", typeof(decimal));
            da.Fill(dt);
            GridView1.DataSource = dt;
            GridView1.DataBind();
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