我第一次使用xsd。
我的任务是： 1.我需要使用c＃读取一个巨大的表格形式mysql。 2.我需要准备xml架构 - 一个表示读取mysql表的xsd文件。
示例代码：
class Program
{
public static DataTable toBeUpdatedTable;
static void Main(string[] args)
{
// Deserialize the stored
string path = "D:\\SerilaizedFile";
ReadMiscInfo(path);
string connectionString = ConfigurationManager.ConnectionStrings["MySQL"].ConnectionString;
MySqlConnection connection = new MySqlConnection(connectionString);
MySqlCommand command;
connection.Open();
DataSet set = new DataSet();
try
{
command = connection.CreateCommand();
command.CommandText = "select * from my_db.table";
MySqlDataAdapter adapter = new MySqlDataAdapter(command);
adapter.Fill(set);
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (connection.State == ConnectionState.Open)
{
connection.Close();
}
}
set.WriteXmlSchema("D:\\file.xsd");
// Modify schema code
DataSet ds = new DataSet();
ds.ReadXmlSchema("D:\\file.xsd");
if (toBeUpdatedTable.Columns.Count > 0)
{
DataTable tempTable = ds.Tables[0];
foreach (DataColumn col in tempTable.Columns)
{
if (!toBeUpdatedTable.Columns.Contains(col.ColumnName))
toBeUpdatedTable.Columns.Add(col.ColumnName, col.DataType);
}
Console.WriteLine("Table Updated");
}
else
{
toBeUpdatedTable = ds.Tables[0];
Console.WriteLine("Table Created");
}
foreach (DataColumn col in toBeUpdatedTable.Columns)
{
Console.WriteLine(col.ColumnName + " type : " + col.DataType);
}
WriteMiscInfo(path);
Console.ReadLine();
}
private static void WriteMiscInfo(string path)
{
if (path != null)
{
Stream s = new FileStream(path, FileMode.Create);
IFormatter f2 = new BinaryFormatter();
f2.Serialize(s, toBeUpdatedTable);
s.Close();
}
}
private static void ReadMiscInfo(string path)
{
if (File.Exists(path))
{
Stream s = new FileStream(path, FileMode.Open, FileAccess.Read);
IFormatter f1 = new BinaryFormatter();
try
{
toBeUpdatedTable = (DataTable)f1.Deserialize(s);
}
catch
{
s.Close();
toBeUpdatedTable = new DataTable();
}
s.Close();
}
else
{
toBeUpdatedTable = new DataTable();
}
}
}
仅帮助我如何修改架构？
答案 0 :(得分：0)
您可以使用此处提到的代码here。
我复制了您的代码并获得了解决方案。但我无法维护数据表的记录。
class Program
{
static void Main(string[] args)
{
// Read a mysql table
string connectionString = ConfigurationManager.ConnectionStrings["MySQL"].ConnectionString;
MySqlConnection connection = new MySqlConnection(connectionString);
MySqlCommand command;
connection.Open();
DataSet set = new DataSet();
try
{
command = connection.CreateCommand();
//command.CommandText = "select * from toolsite.user limit 5";
command.CommandText = "select FirstName, LastName, PersonID, City from my_db.Persons limit 5";
MySqlDataAdapter adapter = new MySqlDataAdapter(command);
adapter.Fill(set);
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (connection.State == ConnectionState.Open)
{
connection.Close();
}
}
// Write Sxml Schema
set.WriteXmlSchema("D:\\file.xsd");
// Modify schema code
FileStream fs = new FileStream("D:\\file.xsd", FileMode.Open);
XmlSchema schema;
ValidationEventHandler eventHandler = new ValidationEventHandler(Program.ShowCompileErrors);
try
{
// Read the schema into an XMLSchema object.
schema = XmlSchema.Read(fs, eventHandler);
// Compile the schema.
schema.Compile(eventHandler);
// Define an XMLSchemaObjectTable to read the schema elements.
// This schematable will contain a single element named "NewDataSet" according to mySql syntax
XmlSchemaObjectTable schematable;
schematable = schema.Elements;
// Define a QualifiedName to identify the elements.
XmlQualifiedName qname = new XmlQualifiedName("NewDataSet", "");
XmlSchemaElement singleElement = new XmlSchemaElement();
XmlSchemaComplexType complextype = new XmlSchemaComplexType();
// See if the XmlSchemaObjectTable has the element.
if (schematable.Contains(qname))
{
singleElement = (XmlSchemaElement)schematable[qname];
if (singleElement.SchemaTypeName.ToString() == "")
{
complextype = (XmlSchemaComplexType)singleElement.SchemaType;
XmlSchemaChoice choice = new XmlSchemaChoice();
choice = (XmlSchemaChoice)complextype.Particle;
XmlSchemaObjectCollection collection = choice.Items;
XmlSchemaObject obj = collection[0];
XmlSchemaComplexType complexsubtype = (XmlSchemaComplexType)((XmlSchemaElement)obj).SchemaType;
XmlSchemaSequence seqelement = new XmlSchemaSequence();
seqelement = (XmlSchemaSequence)complexsubtype.Particle;
// Remove column here
XmlSchemaElement passwordElement = new XmlSchemaElement();
passwordElement = (XmlSchemaElement)seqelement.Items[1];
seqelement.Items.Remove(passwordElement);
// Add any new column here
XmlSchemaElement Newelement = new XmlSchemaElement();
Newelement.Name = "Country";
Newelement.MinOccurs = 0;
Newelement.SchemaTypeName = new XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema");
seqelement.Items.Add(Newelement);
}
}
// Display the schema in the Output window.
schema.Write(Console.Out);
Console.ReadLine();
// Save the modified schema
StreamWriter strmWrtr = new StreamWriter("D:\\newfile.xsd", false);
schema.Write(strmWrtr);
strmWrtr.Close();
}
catch (XmlSchemaException schemaEx)
{
Console.WriteLine(schemaEx.Message);
}
catch (XmlException xmlEx)
{
Console.WriteLine(xmlEx.Message);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
fs.Close();
}
// Read the modified schema
// PROBLEM HERE : My schema is modified but my data of table is lost. I want to just modify the columns .
//I dont want to lose data
set.ReadXmlSchema("D:\\newfile.xsd");
foreach (DataColumn col in set.Tables[0].Columns)
{
Console.WriteLine(col.ColumnName + " type : " + col.DataType);
}
Console.WriteLine("Total records = " + set.Tables[0].Rows.Count);
foreach (DataRow row in set.Tables[0].Rows)
{
for(int i = 0; i < row.ItemArray.Count(); i++)
{
Console.Write(row.ItemArray[i] + " ");
}
Console.WriteLine();
}
Console.ReadLine();
}
public static void ShowCompileErrors(object sender, ValidationEventArgs args)
{
Console.WriteLine("ERROR : Validation Error: {0}", args.Message);
}
}
因此，现在您可能需要有关如何保留数据记录的帮助，数据列应根据模式进行更改。