/// <summary>
/// 创建视图语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForMaintenanceCreateView(GenerateContext context)
{
var operate = (DbCreateViewOperate)context.Data.Operate;
var name = context.ConvertName(operate.Name);
return(new CreateViewFragment(context, name, operate.Statement));
}
/// <summary>
/// 创建数据表语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForMaintenanceCreateTable(GenerateContext context)
{
var operate = (DbCreateTableOperate)context.Data.Operate;
var metadata = context.Metadata.Table(context.Data.Operate.ClrType);
if (operate.Type == EOperateType.CreateTable)
{
var name = context.ConvertName(operate.Name);
return(new CreateTableFragment(context, metadata, name));
}
else
{
var members = metadata.InheritSets.SelectMany(a => a.Members).Concat(metadata.Members);
INameFragment name = null;
if (operate.Type == EOperateType.CreateTempTable)
{
name = new TempTableNameFragment(context, operate.Name.Name);
return(new CreateTempTableFragment(context, members, name)
{
IsVariable = false
});
}
else
{
name = new VariableFragment(context, operate.Name.Name);
return(new CreateTempTableFragment(context, members, name)
{
IsVariable = true
});
}
}
}
/// <summary>
/// 生成删除关系语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForMaintenanceDropRelation(GenerateContext context)
{
var operate = (DbCreateDropRelationOperate)context.Data.Operate;
var name = context.ConvertName(operate.Name);
var fragment = new DropRelationFragment(context, name)
{
Foreign = new ObjectNameFragment(context, operate.Foreign.Name, operate.Foreign.Schema),
};
return(fragment);
}
/// <summary>
/// 删除对象语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForMaintenanceDropObject(GenerateContext context)
{
var operate = (DbDropObjectOperate)context.Data.Operate;
var name = context.ConvertName(operate.Name);
var kind = EDatabaseObject.Table;
switch (operate.Type)
{
case EOperateType.DropTable: kind = EDatabaseObject.Table; break;
case EOperateType.DropView: kind = EDatabaseObject.View; break;
default: throw new NotSupportedException(string.Format(Res.NotSupportedGenerateMaintenance, operate.Type));
}
return(new DropObjectFragment(context, name, kind));
}
/// <summary>
/// 表达式生成删除语句。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="content">生成表达式。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForDeleteStatement(GenerateContext context, DbExpression content)
{
var data = (StatementContent)context.Data;
var item = data.ItemEpxression;
var source = CreateSource(context, content) as QueryBaseFragment;
var table = data.Table;
if (table.InheritSets.Length == 0)
{
var target = (TableFragment)GetSource(context, item);
target.Name = context.ConvertName(data.TargetName);
var delete = new DeleteFragment(context, target)
{
Where = source.Where,
Take = source.Take
};
delete.AddSource(source.Sources.Where(a => a != target));
return(delete);
}
else
{
var createtable = new CreateTempTableFragment(context, table.Keys);
var insert = new InsertFragment(context, createtable.Table, source);
insert.Members.AddRange(createtable.Table.Members);
foreach (var key in table.Keys)
{
RetrievalMember(context, source, new DbMemberExpression(key.Member, item), null, false);
}
var block = new BlockFragment(context, createtable, insert);
foreach (var subtable in table.InheritSets.Concat(new TableMetadata[] { table }).Reverse())
{
var current = new TableFragment(context, subtable);
var delete = new DeleteFragment(context, current);
var temptable = new TemporaryTableFragment(context, table.Keys, createtable.Table.Name);
current.Join(temptable, table.Keys);
delete.AddSource(temptable);
block.Add(delete);
}
return(block);
}
}
/// <summary>
/// 生成创建关系语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForMaintenanceCreateRelation(GenerateContext context)
{
var operate = (DbCreateDropRelationOperate)context.Data.Operate;
var name = context.ConvertName(operate.Name);
var fragment = new CreateRelationFragment(context, name)
{
Foreign = new ObjectNameFragment(context, operate.Foreign.Name, operate.Foreign.Schema),
Principal = new ObjectNameFragment(context, operate.Principal.Name, operate.Principal.Schema),
ForeignKeys = operate.Pairs.Select(a => a.ForeignKey.Name).ToArray(),
PrincipalKeys = operate.Pairs.Select(a => a.PrincipalKey.Name).ToArray()
};
if (operate.Action != null)
{
var action = operate.Action;
fragment.Update = action.Update;
fragment.Delete = action.Delete;
}
return(fragment);
}
