将文本文件转换为SQL数据库表

本文介绍了将文本文件转换为SQL数据库表的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在使用此代码....但只有o和1插入数据库colomnCOLOMN_1 任何身体帮助我 可以将此为循环是错的？

i am using this code ....but only o and 1 are inserted in database colomn "COLOMN_1" any body help me may bi this for loop is wrong??

StreamReader reader = new StreamReader(File.OpenRead(@"D:\GEODATASOURCE-COUNTRY.TXT")); List<string> listA = new List<string>(); List<string> listB = new List<string>(); List<string> listC = new List<string>(); List<string> listD = new List<string>(); //string vara1, vara2, vara3, vara4; while (!reader.EndOfStream) { string line = reader.ReadLine(); if (!String.IsNullOrWhiteSpace(line)) { string[] values = line.Split('\t'); if (values.Length >= 4) { listA.Add(values[0]); listB.Add(values[1]); listC.Add(values[2]); listD.Add(values[3]); } } } string[] firstlistA = listA.ToArray(); string[] firstlistB = listB.ToArray(); string[] firstlistC = listC.ToArray(); string[] firstlistD = listD.ToArray(); for (int i = 0; i < firstlistA.Length; i++) { string query = "INSERT INTO Country (COLOMN_1) VALUES('" +i.ToString() + "')"; con.ConnectionString = @""; SqlCommand com = new SqlCommand(query, con); con.Open(); com = con.CreateCommand(); com.CommandText = query; int c = com.ExecuteNonQuery(); if (c > 0) { con.Close(); } else { con.Close(); } } } }

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推荐答案

是的。它将是。 Well yes. It will be. for (int i = 0; i < firstlistA.Length; i++)

string query = "INSERT INTO Country (COLOMN_1) VALUES('" +i.ToString() + "')";

你期望做什么？ 如果你想插入列表内容，那么我会使用forech循环而不是for：

What did you expect that to do? If you wanted to insert the list content, then I would use a forech loop instead of a for:

foreach (string country in firstListA)

或使用SQL查询将每个列表的内容插入到行中，具体取决于您正在执行的操作。 BTW：不要连接字符串来构建SQL命令。它让您对意外或故意的SQL注入攻击持开放态度，这可能会破坏您的整个数据库。改为使用参数化查询。 它正在工作......但如果我想使用

or use an SQL query to insert the contents of each list into the row, depending on what you are doing. BTW: Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead. "its working ... but if i want use

string[] firstlistA = listA.ToArray(); string[] firstlistB = listB.ToArray(); string[] firstlistC = listC.ToArray(); string[] firstlistD = listD.ToArray();

所有这些数组然后如何将它们插入数据库4 feild table ??? 那么你需要一个的循环 - 但你无需将列表转换为数组。您可以通过它的索引访问列表，就像您可以使用数组一样：

all these arrays then how to insert them in database 4 feild table???" Then you need a for loop - but you don''t need to convert lists to arrays anyway. You can access a list via it''s index just as you can an array:

string sql = "INSERT INTO Country (COLOMN_1, COLOMN_2, COLOMN_3, COLOMN_4) VALUES (@C1, @C2, @C3, @C4)"; for (int i = 0; i < listA.Count; i++) { using (SqlCommand cmd = new SqlCommand(sql, con)) { cmd.Parameters.AddWithValue("@C1", listA[i]); cmd.Parameters.AddWithValue("@C2", listB[i]); cmd.Parameters.AddWithValue("@C3", listC[i]); cmd.Parameters.AddWithValue("@C4", listD[i]); cmd.ExecuteNonQuery(); } }