C#使用OleDb读取Excel,生成SQL语句
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2022-05-17 15:39:54
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C#使用OleDb读取Excel,生成SQL语句
之前在C#读取Excel数据动态生成对象并进行序列化也要对读取Excel文件,那时用的是Microsoft.Office.Interop.Excel组件,有一个致命的问题:读取效率低到不能忽略。所以一直想着有机会去换一个读取的机制,上网google了下,发现使用OleDb读写的效率是很不错的,所以在写把Excel的数据导成SQL语句的工具时,我就使用了OleDb,效率那是毫无疑问的。其实使用Microsoft.Office.Interop.Excel组件去读取Excel是相当于打开一个excel程序,而OleDb其实就是对Excel按数据库的方式进行读写。
少说废话,直接贴代码
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO; using System.Reflection; using Excel = Microsoft.Office.Interop.Excel; using System.Data; using System.Data.OleDb; using System.Windows.Forms; namespace ReadXlsxData { static class ParseXlsx { public static readonly int COMMENT_INDEX=4; //字段说明行下标 public static readonly int KEY_INDEX = 5; //主键行下标 public static readonly int TYPE_INDEX = 6; //字段类型行下标 public static readonly int SQLNAME_INDEX = 7; //数据库字段名行下标 public static readonly int VALUE_INDEX = 8; //value 行下标 public static StringBuilder objectData = new StringBuilder(); public static DataTable ToDataSet(string filePath) { string connStr = ""; string fileType = System.IO.Path.GetExtension(filePath); if (string.IsNullOrEmpty(fileType)) return null; if (fileType == ".xls") connStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + filePath + ";" + ";Extended Properties=\"Excel 8.0;HDR=NO;IMEX=1\""; else connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + filePath + ";" + ";Extended Properties=\"Excel 12.0;HDR=NO;IMEX=1\""; string sql_F = "Select * FROM [{0}]"; OleDbConnection conn = null; OleDbDataAdapter da = null; DataTable dataTable = new DataTable(); try { // 初始化连接,并打开 conn = new OleDbConnection(connStr); conn.Open(); da = new OleDbDataAdapter(); da.SelectCommand = new OleDbCommand(String.Format(sql_F, "Sheet1$"), conn); da.Fill(dataTable); } catch (Exception ex) { } finally { // 关闭连接 if (conn.State == ConnectionState.Open) { conn.Close(); da.Dispose(); conn.Dispose(); } } conn.Close(); da.Dispose(); conn.Dispose(); return dataTable; } public static string ReadExcelFile(string namef, string sqlfile, string sqlcomment) { objectData.Clear(); DataTable dt = ToDataSet(namef); string temp, key,temp1,temp2; List<int> index = new List<int>(); //创建表头 objectData.Append("DROP TABLE IF EXISTS `" + sqlfile + "`;\n"); objectData.Append("CREATE TABLE `" + sqlfile + "` (\n"); int columnSize = dt.Columns.Count; int rowSize = dt.Rows.Count; DataColumn dc; DataRow dr; temp = string.Empty; key = string.Empty; temp1 = string.Empty; temp2 = string.Empty; DataRow dr5 = dt.Rows[COMMENT_INDEX],dr9=dt.Rows[SQLNAME_INDEX],dr8=dt.Rows[TYPE_INDEX]; for (int i = 1; i < columnSize; i++) { dc = dt.Columns[i]; temp2 = dr5[dc].ToString(); temp1 = dr9[dc].ToString(); if (temp2 == string.Empty)//空列判断 break; else if (temp1.ToString() != string.Empty) //数据库字段 { index.Add(i); temp = dr8[dc].ToString(); if (temp.Contains("vachar")) objectData.Append("\t`" + temp1 + "` " + temp + " NOT NULL DEFAULT '' COMMENT '" + temp2 + "',\n"); else objectData.Append("\t`" + temp1 + "` " + temp + " NOT NULL DEFAULT '0' COMMENT '" + temp2 + "',\n"); temp = dt.Rows[KEY_INDEX][dc].ToString(); if (temp != null && temp.Contains("key")) { key += "`" + temp1 + "` "; } } } if(key!=string.Empty) objectData.Append("\tPRIMARY KEY (" + key + ")\n"); objectData.Append(") ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='" + sqlcomment + "';\n"); for (int i = VALUE_INDEX; i < rowSize; i++) //读取数据记录 { objectData.Append("INSERT INTO `" + sqlfile + "` VALUES ('"); dr = dt.Rows[i]; int length = index.Count; for (int j = 0; j < length; j++) { objectData.Append(dr[index[j]] + "','"); } objectData.Remove(objectData.Length - 3, 2); objectData.Append(");\n"); } return objectData.ToString(); } } }
注:这段代码去掉了通用性,只考虑了读取Excel第一个sheet的情况。
下面附上自己做的例子:
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参考:
①Jyson: http://www.cnblogs.com/jys509/archive/2011/07/25/2116143.html
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