c# 大批量資料匯出到excel
阿新 • • 發佈：2021-07-05
我的方法不是使用微軟的excel操作類，因為那種實在爆慢，一個個單元格迴圈寫，實在太慢了。【不信朋友們可以試試】
而使用io寫的話 半分鐘都不用
我資料庫資料量為：120000行 29列
技術要點:1.使用的是StreamWriter sw = new StreamWriter(path, false,Encoding.GetEncoding("gb2312"));最終生成檔案
2.使用 StringBuilder sb = new StringBuilder();類把查詢出來的資料組合為一句超長字串一次性插入到excel中，
sb.Append(ds.Tables[0].Columns[k].ColumnName.ToString() + "\t");
注意，可不能漏了"\t" 這個是非常重要的！ 因為c# "\t"就等於 鍵盤上的Tab
[朋友們可以試試：開啟新的txt然後輸入1按Tab，輸入2按Tab，輸入3按Tab儲存，然後開啟excel檔案
把剛剛儲存的txt檔案拉進去開啟你就發現原來。這樣寫的話1 2 3 會分別在每個單元格上的了。所以上面才使用
"\t"連起來資料庫出來的那堆資料，這樣一次性導進去，他們就會按照每個單元格來填充！]
需要引用：
using System.Threading;
using System.IO;
方法如下：
-
private void button1_Click(object sender, EventArgs e)
- {
-
saveFileDialog1.Title = "儲存的excel檔案";
-
saveFileDialog1.InitialDirectory = "c:\\";
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saveFileDialog1.Filter = "Excel97-2003 (*.xls)|*.xls|All Files (*.*)|*.*";
- saveFileDialog1.ShowDialog();
-
if (saveFileDialog1.FileName == "" || saveFileDialog1.FileName == null)
- {
-
MessageBox.Show("檔名不能為空!");
-
return;
- }
-
string path = saveFileDialog1.FileName;
-
string constr = "Data Source=.;Initial Catalog=Exhibition;User ID=sa;Password=";
-
string sql = GetStrSql();
-
DataSet ds=new DataSet();
-
using (SqlConnection con = new SqlConnection(constr))
- {
-
SqlDataAdapter da = new SqlDataAdapter(sql, con);
- da.Fill(ds);
- }
-
if (ds == null)
- {
-
MessageBox.Show("資料獲取有誤!");
-
return;
- }
- WriteExcel(ds, path);
- }
-
public void WriteExcel(DataSet ds, string path)
- {
-
try
- {
-
long totalCount = ds.Tables[0].Rows.Count;
-
lblTip.Text = "共有" + totalCount + "條資料。";
-
Thread.Sleep(1000);
-
long rowRead = 0;
-
float percent = 0;
-
StreamWriter sw = new StreamWriter(path, false,Encoding.GetEncoding("gb2312"));
-
StringBuilder sb = new StringBuilder();
-
for (int k = 0; k < ds.Tables[0].Columns.Count; k++)
- {
-
sb.Append(ds.Tables[0].Columns[k].ColumnName.ToString() + "\t");
- }
- sb.Append(Environment.NewLine);
-
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
- {
- rowRead++;
-
percent = ((float)(100 * rowRead)) / totalCount;
-
Pbar.Maximum = (int)totalCount;
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Pbar.Value = (int)rowRead;
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lblTip.Text = "正在寫入[" + percent.ToString("0.00") + "%]...的資料";
- System.Windows.Forms.Application.DoEvents();
-
for (int j = 0; j < ds.Tables[0].Columns.Count; j++)
- {
-
sb.Append(ds.Tables[0].Rows[i][j].ToString() + "\t");
- }
- sb.Append(Environment.NewLine);
- }
- sw.Write(sb.ToString());
- sw.Flush();
- sw.Close();
-
MessageBox.Show("已經生成指定Excel檔案!");
- }
-
catch (Exception ex)
- {
- MessageBox.Show(ex.Message);
- }
- }
-
public string GetStrSql()
- {
-
string strSql = "select d.* from ( select cBarcode ,max(case halldoorid When '36' then '1' else '0' end ) [1.1號館],max(case halldoorid When '37' then '1' else '0' end ) [2.1號館],max(case halldoorid When '38' then '1' else '0' end ) [3.1號館],max(case halldoorid When '39' then '1' else '0' end ) [4.1號館],max(case halldoorid When '40' then '1' else '0' end ) [5.1號館],max(case halldoorid When '41' then '1' else '0' end ) [6.1號館],max(case halldoorid When '42' then '1' else '0' end ) [8.1號館],max(case halldoorid When '43' then '1' else '0' end ) [1.2號館],max(case halldoorid When '44' then '1' else '0' end ) [2.2號館],max(case halldoorid When '45' then '1' else '0' end ) [3.2號館],max(case halldoorid When '46' then '1' else '0' end ) [4.2號館],max(case halldoorid When '47' then '1' else '0' end ) [5.2號館],max(case halldoorid When '48' then '1' else '0' end ) [9.1號館],max(case halldoorid When '49' then '1' else '0' end ) [10.1號館],max(case halldoorid When '50' then '1' else '0' end ) [11.1號館],max(case halldoorid When '51' then '1' else '0' end ) [12.1號館],max(case halldoorid When '52' then '1' else '0' end ) [13.1號館],max(case halldoorid When '53' then '1' else '0' end ) [9.2號館],max(case halldoorid When '54' then '1' else '0' end ) [10.2號館],max(case halldoorid When '55' then '1' else '0' end ) [11.2號館],max(case halldoorid When '56' then '1' else '0' end ) [12.2號館],max(case halldoorid When '57' then '1' else '0' end ) [13.2號館],max(case halldoorid When '58' then '1' else '0' end ) [9.3號館],max(case halldoorid When '59' then '1' else '0' end ) [10.3號館],max(case halldoorid When '60' then '1' else '0' end ) [11.3號館],max(case halldoorid When '61' then '1' else '0' end ) [VIP3.2號館],max(case halldoorid When '62' then '1' else '0' end ) [VIP11.3號館],max(case halldoorid When '63' then '1' else '0' end ) [VIP14.3號館]from tblReadCard group by cBarcode ) d left join ( select cBarcode 觀眾條碼 from (select distinct cBarcode,cReadDate from tblReadCard where cReadDate between '2011-07-08' and '2011-07-11') a group by cBarcode ) c on d.cBarcode=c.觀眾條碼 group by cBarcode,[1.1號館],[2.1號館],[3.1號館],[4.1號館],[5.1號館],[6.1號館],[8.1號館],[1.2號館],[2.2號館],[3.2號館],[4.2號館],[5.2號館],[9.1號館],[10.1號館],[11.1號館],[12.1號館],[13.1號館],[9.2號館],[10.2號館],[11.2號館],[12.2號館],[13.2號館],[9.3號館],[10.3號館],[11.3號館],[VIP3.2號館],[VIP11.3號館],[VIP14.3號館]";
-
return strSql;
- }