在以前的文章《如何在.NET框架下创建Access数据库和表?》中提供的方法,在.NET 2.0下无效,所有的字段类型都变成了文本类型,不知道微软改变了什么东西。提醒大家注意,需要加ADOX.ColumnClass.Type = DataTypeEnum.adLongVarBinary属性。下面将修正后的代码发布如下。
C#:
<%@ Page Language="C#" %>
<%@ Import Namespace="ADOX" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
/// <summary>
/// CreateAccessDB 的摘要说明。
/// 对于不同版本的ADO,需要添加不同的引用
/// 请添加引用Microsoft ADO Ext. 2.7 for DDL and Security
/// 请添加引用Microsoft ADO Ext. 2.8 for DDL and Security
/// </summary>
protected void Page_Load(object sender, EventArgs e)
{
//为了方便测试,数据库名字采用比较随机的名字,以防止添加不成功时还需要重新启动IIS来删除数据库。
string dbName = "D:\NewMDB" + DateTime.Now.Millisecond.ToString() + ".mdb";
ADOX.CatalogClass cat = new ADOX.CatalogClass();
cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbName + ";");
Response.Write("数据库:" + dbName + "已经创建成功!");
ADOX.TableClass tbl = new ADOX.TableClass();
tbl.ParentCatalog = cat;
tbl.Name = "MyTable";
//增加一个自动增长的字段
ADOX.ColumnClass col = new ADOX.ColumnClass();
col.ParentCatalog = cat;
col.Type = ADOX.DataTypeEnum.adInteger; // 必须先设置字段类型
col.Name = "id";
col.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
col.Properties["AutoIncrement"].Value = true;
tbl.Columns.Append(col, ADOX.DataTypeEnum.adInteger, 0);
//增加一个文本字段
ADOX.ColumnClass col2 = new ADOX.ColumnClass();
col2.ParentCatalog = cat;
col2.Name = "Description";
col2.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
tbl.Columns.Append(col2, ADOX.DataTypeEnum.adVarChar, 25);
//增加数字字段
ADOX.ColumnClass col3 = new ADOX.ColumnClass();
col3.ParentCatalog = cat;
col3.Name = "数字";
col3.Type = DataTypeEnum.adDouble;
col3.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
tbl.Columns.Append(col3, ADOX.DataTypeEnum.adDouble, 666);
//增加Ole字段
ADOX.ColumnClass col4 = new ADOX.ColumnClass();
col4.ParentCatalog = cat;
col4.Name = "Ole类型";
col4.Type = DataTypeEnum.adLongVarBinary;
col4.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
tbl.Columns.Append(col4, ADOX.DataTypeEnum.adLongVarBinary, 0);
//设置主键
tbl.Keys.Append("PrimaryKey", ADOX.KeyTypeEnum.adKeyPrimary, "id", "", "");
cat.Tables.Append(tbl);
msg.Text = ("<br>数据库表:" + tbl.Name + "已经创建成功!");
System.Runtime.InteropServices.Marshal.ReleaseComObject(tbl);
System.Runtime.InteropServices.Marshal.ReleaseComObject(cat);
tbl = null;
cat = null;
GC.WaitForPendingFinalizers();
GC.Collect();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>在.NET框架下动态创建Access数据库和表</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Label ID="msg" runat="server" />
</form>
</body>
</html>
VB.NET:
<%@ Page Language="VB" %>
<%@ Import Namespace="ADOX" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
Dim dbName As String = "D:NewMDB" + DateTime.Now.Millisecond.ToString + ".mdb"
Dim cat As ADOX.CatalogClass = New ADOX.CatalogClass
cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbName + ";")
Response.Write("数据库:" + dbName + "已经创建成功!")
Dim tbl As ADOX.TableClass = New ADOX.TableClass
tbl.ParentCatalog = cat
tbl.Name = "MyTable"
Dim col As ADOX.ColumnClass = New ADOX.ColumnClass
col.ParentCatalog = cat
col.Type = ADOX.DataTypeEnum.adInteger
col.Name = "id"
col.Properties("Jet OLEDB:Allow Zero Length").Value = False
col.Properties("AutoIncrement").Value = True
tbl.Columns.Append(col, ADOX.DataTypeEnum.adInteger, 0)
Dim col2 As ADOX.ColumnClass = New ADOX.ColumnClass
col2.ParentCatalog = cat
col2.Name = "Description"
col2.Properties("Jet OLEDB:Allow Zero Length").Value = False
tbl.Columns.Append(col2, ADOX.DataTypeEnum.adVarChar, 25)
Dim col3 As ADOX.ColumnClass = New ADOX.ColumnClass
col3.ParentCatalog = cat
col3.Name = "数字"
col3.Type = DataTypeEnum.adDouble
col3.Properties("Jet OLEDB:Allow Zero Length").Value = False
tbl.Columns.Append(col3, ADOX.DataTypeEnum.adDouble, 666)
Dim col4 As ADOX.ColumnClass = New ADOX.ColumnClass
col4.ParentCatalog = cat
col4.Name = "Ole类型"
col4.Type = DataTypeEnum.adLongVarBinary
tbl.Columns.Append(col4, ADOX.DataTypeEnum.adLongVarBinary, 0)
tbl.Keys.Append("PrimaryKey", ADOX.KeyTypeEnum.adKeyPrimary, "id", "", "")
cat.Tables.Append(tbl)
msg.Text = ("<br>数据库表:" + tbl.Name + "已经创建成功!")
System.Runtime.InteropServices.Marshal.ReleaseComObject(tbl)
System.Runtime.InteropServices.Marshal.ReleaseComObject(cat)
tbl = Nothing
cat = Nothing
GC.WaitForPendingFinalizers()
GC.Collect()
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>在.NET框架下动态创建Access数据库和表</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Label ID="msg" runat="server" />
</form>
</body>
</html>
【Update】下面的代码添加对现有数据库的字段添加:
<%@ 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">
/// <summary>
/// CreateAccessDB 的摘要说明。
/// 对于不同版本的ADO,需要添加不同的引用
/// 请添加引用: Microsoft ADO Ext. 2.7 for DDL and Security
/// 请添加引用: Microsoft ADO Ext. 2.8 for DDL and Security
/// 另外,如果修改数据库,需要添加引用: Microsoft ActiveX Data Objects 2.8 Library
/// </summary>
protected void Page_Load( object sender, EventArgs e )
{
//为了方便测试,数据库名字采用比较随机的名字,以防止添加不成功时还需要重新启动IIS来删除数据库。
string dbName = Server.MapPath("~") + "\NewMDB" + DateTime.Now.Millisecond.ToString() + ".mdb";
ADOX.CatalogClass cat = new ADOX.CatalogClass();
cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbName + ";");
Response.Write("数据库:" + dbName + "已经创建成功!");
ADOX.TableClass tbl = new ADOX.TableClass();
tbl.ParentCatalog = cat;
tbl.Name = "MyTable";
//增加一个自动增长的字段
ADOX.ColumnClass col = new ADOX.ColumnClass();
col.ParentCatalog = cat;
col.Type = ADOX.DataTypeEnum.adInteger; // 必须先设置字段类型
col.Name = "id";
col.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
col.Properties["AutoIncrement"].Value = true;
tbl.Columns.Append(col, ADOX.DataTypeEnum.adInteger, 0);
//增加一个文本字段
ADOX.ColumnClass col2 = new ADOX.ColumnClass();
col2.ParentCatalog = cat;
col2.Name = "Description";
col2.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
tbl.Columns.Append(col2, ADOX.DataTypeEnum.adVarChar, 25);
//增加数字字段
ADOX.ColumnClass col3 = new ADOX.ColumnClass();
col3.ParentCatalog = cat;
col3.Name = "数字类型字段";
col3.Type = ADOX.DataTypeEnum.adDouble;
col3.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
tbl.Columns.Append(col3, ADOX.DataTypeEnum.adDouble, 666);
//增加Ole字段
ADOX.ColumnClass col4 = new ADOX.ColumnClass();
col4.ParentCatalog = cat;
col4.Name = "Ole类型字段";
col4.Type = ADOX.DataTypeEnum.adLongVarBinary;
col4.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
tbl.Columns.Append(col4, ADOX.DataTypeEnum.adLongVarBinary, 0);
Response.Write("<h4>得到各个列的名字:</h4>");
for (int i = 0 ; i < tbl.Columns.Count ; i++)
{
Response.Write("<li>" + i.ToString() + " = " + tbl.Columns[i].Name + " 类型:" + tbl.Columns[i].Type.ToString());
}
Response.Write("<h4>删除 Description 列:</h4>");
tbl.Columns.Delete("Description");
tbl.Columns.Refresh();
Response.Write("<h4>修改 “数字类型字段” 列名字:</h4>");
ADOX.ColumnClass col5 = (ADOX.ColumnClass)tbl.Columns["数字类型字段"];
col5.Name = "新名字类型字段";
tbl.Columns.Refresh();
//设置主键
tbl.Keys.Append("PrimaryKey", ADOX.KeyTypeEnum.adKeyPrimary, "id", "", "");
cat.Tables.Append(tbl);
Response.Write("<br>数据库表:" + tbl.Name + "已经创建成功!");
Response.Write("<h4>修改现有数据库:</h4>");
//打开已经存在的数据库,添加字段
string ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbName;
ADODB.Connection cn = new ADODB.Connection();
cn.Open(ConnectionString, null, null, 0);
cat = new ADOX.CatalogClass();
cat.ActiveConnection = cn;
Response.Write("数据库:" + dbName + "已经打开成功!");
ADOX.Table dbTable = cat.Tables["MyTable"];
//增加一个文本字段
ADOX.Column newColumn = new ADOX.Column();
newColumn.ParentCatalog = cat;
newColumn.Name = "Address";
newColumn.Properties["Jet OLEDB:Allow Zero Length"].Value = false;
dbTable.Columns.Append(newColumn, ADOX.DataTypeEnum.adVarChar, 255);
Response.Write("<br>数据库表:" + dbTable.Name + "修改成功!");
cn.Close();
System.Runtime.InteropServices.Marshal.ReleaseComObject(tbl);
System.Runtime.InteropServices.Marshal.ReleaseComObject(dbTable);
System.Runtime.InteropServices.Marshal.ReleaseComObject(cat);
System.Runtime.InteropServices.Marshal.ReleaseComObject(cn);
col = null;
col2 = null;
col3 = null;
col4 = null;
col5 = null;
newColumn = null;
tbl = null;
dbTable = null;
cat = null;
GC.WaitForPendingFinalizers();
GC.Collect();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>创建、修改 Access 数据库</title>
</head>
<body>
<form id="Mengxianhui" runat="server"></form>
</body>
</html>
查看本文来源