private void btnAddRelation_Click(Object sender, EventArgs e)
{
IDataTable table = GetSelectedTable();
if (table == null)
{
return;
}
IDataRelation dr = table.CreateRelation();
table.Relations.Add(dr);
dgvRelation.DataSource = null;
dgvRelation.DataSource = table.Relations;
pgColumn.SelectedObject = dr;
}
/// <summary>复制数据表到另一个数据表，复制所有数据列、索引和关系</summary>
/// <param name="src"></param>
/// <param name="des"></param>
/// <param name="resetColumnID">是否重置列ID</param>
/// <returns></returns>
public static IDataTable CopyAllFrom(this IDataTable src, IDataTable des, Boolean resetColumnID = false)
{
src.CopyFrom(des);
src.Columns.AddRange(des.Columns.Select(i => src.CreateColumn().CopyFrom(i)));
src.Indexes.AddRange(des.Indexes.Select(i => src.CreateIndex().CopyFrom(i)));
src.Relations.AddRange(des.Relations.Select(i => src.CreateRelation().CopyFrom(i)));
// 重载ID
//if (resetColumnID) src.Columns.ForEach((it, i) => it.ID = i + 1);
if (resetColumnID)
{
for (int i = 0; i < src.Columns.Count; i++)
{
src.Columns[i].ID = i + 1;
}
}
return(src);
}
/// <summary>猜测表间关系</summary>
/// <param name="table"></param>
/// <param name="rtable"></param>
/// <param name="rname"></param>
/// <param name="column"></param>
/// <param name="name"></param>
/// <returns></returns>
public virtual Boolean GuessRelation(IDataTable table, IDataTable rtable, String rname, IDataColumn column, String name)
{
if (name.Length <= rtable.Name.Length || !name.StartsWith(rtable.Name, StringComparison.OrdinalIgnoreCase)) return false;
var key = name.Substring(rtable.Name.Length);
var dc = rtable.GetColumn(key);
// 猜测两表关联关系时，两个字段的类型也必须一致
if (dc == null || dc.DataType != column.DataType) return false;
// 建立关系
var dr = table.CreateRelation();
dr.Column = column.Name;
dr.RelationTable = rtable.Name;
dr.RelationColumn = dc.Name;
// 表关系这里一般是多对一，比如管理员的RoleID=>Role+Role.ID，对于索引来说，不是唯一的
dr.Unique = false;
// 当然，如果这个字段column有唯一索引，那么，这里也是唯一的。这就是典型的一对一
if (column.PrimaryKey || column.Identity)
dr.Unique = true;
else
{
var di = table.GetIndex(column.Name);
if (di != null && di.Unique) dr.Unique = true;
}
dr.Computed = true;
if (table.GetRelation(dr) == null) table.Relations.Add(dr);
// 给另一方建立关系
//foreach (IDataRelation item in rtable.Relations)
//{
// if (item.Column == dc.Name && item.RelationTable == table.Name && item.RelationColumn == column.Name) return dr;
//}
if (rtable.GetRelation(dc.Name, table.Name, column.Name) != null) return true;
dr = rtable.CreateRelation();
dr.Column = dc.Name;
dr.RelationTable = table.Name;
dr.RelationColumn = column.Name;
// 那么这里就是唯一的啦
dr.Unique = true;
// 当然，如果字段dc不是主键，也没有唯一索引，那么关系就不是唯一的。这就是典型的多对多
if (!dc.PrimaryKey && !dc.Identity)
{
var di = rtable.GetIndex(dc.Name);
// 没有索引，或者索引不是唯一的
if (di == null || !di.Unique) dr.Unique = false;
}
dr.Computed = true;
if (rtable.GetRelation(dr) == null) rtable.Relations.Add(dr);
return true;
}
/// <summary>读取</summary>
/// <param name="table"></param>
/// <param name="reader"></param>
/// <returns></returns>
public static IDataTable ReadXml(this IDataTable table, XmlReader reader)
{
// 读属性
if (reader.HasAttributes)
{
reader.MoveToFirstAttribute();
ReadXml(reader, table);
}
reader.ReadStartElement();
// 读字段
reader.MoveToElement();
// 有些数据表模型没有字段
if (reader.NodeType == XmlNodeType.Element && reader.Name.EqualIgnoreCase("Table"))
{
return(table);
}
while (reader.NodeType != XmlNodeType.EndElement)
//while (reader.NodeType == XmlNodeType.Element)
{
switch (reader.Name)
{
case "Columns":
reader.ReadStartElement();
var id = 1;
while (reader.IsStartElement())
{
var dc = table.CreateColumn();
dc.ID = id++;
var v = reader.GetAttribute("DataType");
if (v != null)
{
dc.DataType = v.GetTypeEx();
v = reader.GetAttribute("Length");
var len = 0;
if (v != null && Int32.TryParse(v, out len))
{
dc.Length = len;
}
// 含有ID表示是旧的，不需要特殊处理，否则一些默认值会不对
v = reader.GetAttribute("ID");
if (v == null)
{
dc = Fix(dc, dc);
}
}
(dc as IXmlSerializable).ReadXml(reader);
table.Columns.Add(dc);
}
reader.ReadEndElement();
// 修正可能的主字段
if (!table.Columns.Any(e => e.Master))
{
var f = table.Columns.FirstOrDefault(e => e.Name.EqualIgnoreCase("Name", "Title"));
if (f != null)
{
f.Master = true;
}
}
break;
case "Indexes":
reader.ReadStartElement();
while (reader.IsStartElement())
{
var di = table.CreateIndex();
(di as IXmlSerializable).ReadXml(reader);
di.Fix();
table.Indexes.Add(di);
}
reader.ReadEndElement();
break;
case "Relations":
reader.ReadStartElement();
while (reader.IsStartElement())
{
var dr = table.CreateRelation();
(dr as IXmlSerializable).ReadXml(reader);
if (table.GetRelation(dr) == null)
{
table.Relations.Add(dr);
}
}
reader.ReadEndElement();
break;
default:
// 这里必须处理，否则加载特殊Xml文件时将会导致死循环
reader.Read();
break;
}
}
//if (reader.NodeType != XmlNodeType.Element && reader.NodeType != XmlNodeType.EndElement) reader.Read();
//reader.ReadEndElement();
if (reader.NodeType == XmlNodeType.EndElement)
{
reader.ReadEndElement();
}
return(table);
}
/// <summary>猜测表间关系</summary>
/// <param name="table"></param>
/// <param name="rtable"></param>
/// <param name="rname"></param>
/// <param name="column"></param>
/// <param name="name">名称</param>
/// <returns></returns>
public virtual Boolean GuessRelation(IDataTable table, IDataTable rtable, String rname, IDataColumn column, String name)
{
if (table == null || rtable == null || rname == null || column == null || name == null)
{
return(false);
}
if (name.Length <= rtable.TableName.Length || !name.StartsWithIgnoreCase(rtable.TableName))
{
return(false);
}
var key = name.Substring(rtable.TableName.Length);
var dc = rtable.GetColumn(key);
// 猜测两表关联关系时，两个字段的类型也必须一致
if (dc == null || dc.DataType != column.DataType)
{
return(false);
}
// 建立关系
var dr = table.CreateRelation();
dr.Column = column.ColumnName;
dr.RelationTable = rtable.TableName;
dr.RelationColumn = dc.ColumnName;
// 表关系这里一般是多对一，比如管理员的RoleID=>Role+Role.ID，对于索引来说，不是唯一的
dr.Unique = false;
// 当然，如果这个字段column有唯一索引，那么，这里也是唯一的。这就是典型的一对一
if (column.PrimaryKey || column.Identity)
{
dr.Unique = true;
}
else
{
var di = table.GetIndex(column.ColumnName);
if (di != null && di.Unique)
{
dr.Unique = true;
}
}
dr.Computed = true;
if (table.GetRelation(dr) == null)
{
table.Relations.Add(dr);
}
// 给另一方建立关系
if (rtable.GetRelation(dc.ColumnName, table.TableName, column.ColumnName) != null)
{
return(true);
}
dr = rtable.CreateRelation();
dr.Column = dc.ColumnName;
dr.RelationTable = table.TableName;
dr.RelationColumn = column.ColumnName;
// 那么这里就是唯一的啦
dr.Unique = true;
// 当然，如果字段dc不是主键，也没有唯一索引，那么关系就不是唯一的。这就是典型的多对多
if (!dc.PrimaryKey && !dc.Identity)
{
var di = rtable.GetIndex(dc.ColumnName);
// 没有索引，或者索引不是唯一的
if (di == null || !di.Unique)
{
dr.Unique = false;
}
}
dr.Computed = true;
if (rtable.GetRelation(dr) == null)
{
rtable.Relations.Add(dr);
}
return(true);
}
/// <summary>读取</summary>
/// <param name="table"></param>
/// <param name="reader"></param>
/// <returns></returns>
public static IDataTable ReadXml(this IDataTable table, XmlReader reader)
{
// 读属性
if (reader.HasAttributes)
{
reader.MoveToFirstAttribute();
//do
//{
// switch (reader.Name)
// {
// case "ID":
// table.ID = reader.ReadContentAsInt();
// break;
// case "Name":
// table.Name = reader.ReadContentAsString();
// break;
// case "Alias":
// table.Alias = reader.ReadContentAsString();
// break;
// case "Owner":
// table.Owner = reader.ReadContentAsString();
// break;
// case "DbType":
// table.DbType = (DatabaseType)Enum.Parse(typeof(DatabaseType), reader.ReadContentAsString());
// break;
// case "IsView":
// table.IsView = Boolean.Parse(reader.ReadContentAsString());
// break;
// case "Description":
// table.Description = reader.ReadContentAsString();
// break;
// default:
// break;
// }
//} while (reader.MoveToNextAttribute());
ReadXml(reader, table);
}
reader.ReadStartElement();
// 读字段
reader.MoveToElement();
while (reader.NodeType != XmlNodeType.EndElement)
{
switch (reader.Name)
{
case "Columns":
reader.ReadStartElement();
while (reader.IsStartElement())
{
var dc = table.CreateColumn();
(dc as IXmlSerializable).ReadXml(reader);
table.Columns.Add(dc);
}
reader.ReadEndElement();
break;
case "Indexes":
reader.ReadStartElement();
while (reader.IsStartElement())
{
var di = table.CreateIndex();
(di as IXmlSerializable).ReadXml(reader);
table.Indexes.Add(di);
}
reader.ReadEndElement();
break;
case "Relations":
reader.ReadStartElement();
while (reader.IsStartElement())
{
var dr = table.CreateRelation();
(dr as IXmlSerializable).ReadXml(reader);
if (table.GetRelation(dr) == null)
{
table.Relations.Add(dr);
}
}
reader.ReadEndElement();
break;
default:
break;
}
}
//reader.ReadEndElement();
if (reader.NodeType == XmlNodeType.EndElement)
{
reader.ReadEndElement();
}
return(table);
}
