在实际的开发应用中,数据库导入导出是经常遇到的问题,尤其是数据库与Excel文件之间的导入导出,还存在数据类型不一致的问题。例如:数据库的数字超长时会在Excel里格式化成科学计数法的格式,或者记录内容是数字和字符的混合内容会丢失内容等等。将Access数据库的内容直接导入到Excel则可以避免这些问题。
下面例子就是实现这个功能,例子中的数据库使用《ASP.NET 2.0应用开发技术》一书中自带的数据库为例子。
另外,需要注意:Excel文件有诸多限制,在如果数据库记录内容很多,还要计算每次导出的数量和Sheet数目,另外,对Sheet名字相同的监测也省略了,需要的读者请根据情况自行添加上去。结合存储过程的分页功能实现起来比较好。
C#:
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional //EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Button1_Click(object sender, EventArgs e)
{
string sql;
string connstr = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=|DataDirectory|ASPNET20Book.mdb;Persist Security Info=True";
System.Data.OleDb.OleDbConnection cn = new System.Data.OleDb.OleDbConnection(connstr);
System.Data.OleDb.OleDbCommand cmd;
cn.Open();
//先得到记录数目:
sql = "select Count(*) From Paging";
cmd = new System.Data.OleDb.OleDbCommand(sql, cn);
int RecordCount = (int)cmd.ExecuteScalar();
// TODO:计算Sheet数目,进行记录分段, 将不同的数据段导入到不同的Sheet(Sheet数目不知道有没有限制:())
// TODO:文件名,Sheet名字的存在检测略
//每个Sheet只能最多保存65536条记录。
sql = @"select top 65535 * into [Excel 8.0;database=" + Server.MapPath(".") + @"ASPNET20Book.xls].[Sheet1] from Paging";
cmd = new System.Data.OleDb.OleDbCommand(sql, cn);
cmd.ExecuteNonQuery();
cn.Close();
cn.Dispose();
cn = null;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>直接将Access数据库导入到Excel文件</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="到处数据">
</form>
</body>
</html>
VB.NET:
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim sql As String
Dim connstr As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|ASPNET20Book.mdb;Persist Security Info=True"
Dim cn As System.Data.OleDb.OleDbConnection = New System.Data.OleDb.OleDbConnection(connstr)
Dim cmd As System.Data.OleDb.OleDbCommand
cn.Open
sql = "select Count(*) From Paging"
cmd = New System.Data.OleDb.OleDbCommand(sql, cn)
Dim RecordCount As Integer = CType(cmd.ExecuteScalar, Integer)
sql = "select top 65535 * into [Excel 8.0;database=" + Server.MapPath(".") + "ASPNET20Book.xls].[Sheet1] from Paging"
cmd = New System.Data.OleDb.OleDbCommand(sql, cn)
cmd.ExecuteNonQuery
cn.Close
cn.Dispose
cn = Nothing
End Sub