/// <summary>
/// 根据指定类型<see cref="DbSetConnectExpression"/>表达式创建数据源语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="expression">指定表达式。</param>
/// <returns>创建结果。</returns>
protected virtual ISourceFragment CreateSourceForSetConnect(GenerateContext context, DbExpression expression)
{
var content = (DbSetConnectExpression)expression;
var source = CreateSource(context, content.Source);
var target = CreateSource(context, content.Target);
if (source is SetFragment select)
{
select.AddSource(target, content.Kind);
}
else
{
select = new SetFragment(context, source);
select.AddSource(target, content.Kind);
}
context.RegisterSource(content, select);
if (!select.Members.Any())
{
var unittype = content.Source as DbUnitTypeExpression;
var members = RetrievalMembers(context, source, unittype.Item, false);
select.Members.AddRange(members.Select(a => CreateMember(context, select, a.Property, a)));
}
if (!target.Members.Any())
{
var unittype = content.Target as DbUnitTypeExpression;
RetrievalMembers(context, target, unittype.Item, false).ToArray();
}
context.RegisterSource(content.Item, select);
if (IsSelectFragment(content))
{
return(InitialSelectFragment(new SelectFragment(context, select), content));
}
return(select);
}
/// <summary>
/// 根据指定类型<see cref="DbDataSetExpression"/>表达式创建数据源语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="expression">指定表达式。</param>
/// <returns>创建结果。</returns>
protected virtual ISourceFragment CreateSourceForDataSet(GenerateContext context, DbExpression expression)
{
var content = (DbDataSetExpression)expression;
var metadata = context.Metadata.Table(content.Item.ClrType);
SourceFragment table = null;
if (metadata.InheritSets.Length > 0)
{
if (content.Name != null)
{
throw new NotSupportedException(Res.NotSupportedInheritSetUsingDbName);
}
table = new InheritFragment(context, metadata);
}
else
{
table = new TableFragment(context, content);
}
context.RegisterSource(content.Item, table);
context.RegisterSource(content, table);
if (IsSelectFragment(content))
{
return(InitialSelectFragment(new SelectFragment(context, table), content));
}
if (table is InheritFragment inherit)
{
inherit.Initialize();
}
return(table);
}
//生成前注册相关表达式。
private void GenerateForUpdateRegister(GenerateContext context, DbExpression content, ISourceFragment source)
{
if (content != null && content is DbSelectExpression select)
{
context.RegisterSource(select.Source, source, true);
context.RegisterSource(select.Source.Item, source, true);
}
}
/// <summary>
/// 生成用于插入数据项的语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="content">插入表达式。</param>
/// <returns>生成结果。</returns>
protected virtual SqlFragment GenerateForInsert(GenerateContext context, DbExpression content = null)
{
var data = (GenerateDataForInsert)context.Data;
if (content != null && content is DbSelectExpression select)
{
context.RegisterSource(select.Source, data.CommitObject);
context.RegisterSource(select.Source.Item, data.CommitObject);
}
try
{
if (data.MainUnit is CommitKeyUnit keyunit)
{ //没有标识列
if (data.Items.Count > 1)
{ //多个
if (data.HasExpressionKey || data.ReturnMembers.Any())
{
return(GenerateForInsertTempTable(context));
}
else
{
return(GenerateForInsertSimple(context));
}
}
else
{//单个
if (data.HasExpressionKey)
{
return(GenerateForInsertTempTable(context));
}
else
{
return(GenerateForInsertSimple(context));
}
}
}
else
{ //标识列
if (data.Items.Count > 1 || !context.Feature.HasCapable(EDbCapable.ExternalLocalVariable))
{ //多个
return(GenerateForInsertIdentityTempTable(context));
}
else
{//单个
return(GenerateForInsertIdentitySingle(context));
}
}
}
finally
{
data.GenerateOutput();
}
}
/// <summary>
/// 根据指定类型<see cref="DbGroupByExpression"/>表达式创建数据源语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="expression">指定表达式。</param>
/// <returns>创建结果。</returns>
protected virtual ISourceFragment CreateSourceForGroupBy(GenerateContext context, DbExpression expression)
{
var content = (DbGroupByExpression)expression;
var groupitem = (DbGroupItemExpression)content.Item;
var source = CreateSource(context, content.Source);
var body = new SelectFragment(context, source);
body.RetrievalMembers(content.Key, false);
foreach (var member in body.Members.OfType <ReferenceMemberFragment>())
{
body.GroupBys.Add(member.Reference);
}
var container = new SelectFragment(context, body);
var virtualSource = new VirtualSourceFragment(context, expression, container, source, body);
context.RegisterSource(content, virtualSource);
context.RegisterSource(content.Item, virtualSource);
return(container);
}
/// <summary>
/// 根据指定类型<see cref="DbCollectionMemberExpression"/>表达式创建数据源语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="expression">指定表达式。</param>
/// <returns>创建结果。</returns>
protected virtual ISourceFragment CreateSourceForCollectionMember(GenerateContext context, DbExpression expression)
{
var content = (DbCollectionMemberExpression)expression;
var source = GetSource(context, content.Expression);
var target = CreateSource(context, content.TargetSet);
var container = (SelectFragment)source.Parent;
var virtualSource = new VirtualSourceFragment(context, expression, container, source);
context.RegisterSource(content, virtualSource);
return(virtualSource);
}
/// <summary>
/// 根据指定类型<see cref="DbObjectMemberExpression"/>表达式创建数据源语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="expression">指定表达式。</param>
/// <returns>创建结果。</returns>
protected virtual ISourceFragment CreateSourceForObjectMember(GenerateContext context, DbExpression expression)
{
var content = (DbObjectMemberExpression)expression;
var source = GetSource(context, content.Expression);
if (source is VirtualSourceFragment virtualSource)
{
return(virtualSource.GetBody());
}
else
{
var select = (SelectFragment)source.Parent;
if (select.IsRecommandLock)
{
select = select.Parent as SelectFragment;
}
var pairs = content.Pairs;
if (content.CompositePairs != null)
{
var relation = CreateSource(context, content.RelationSet);
select.AddSource(relation);
context.RegisterSource(content.RelationSet, relation);
relation.Join = EJoinType.LeftJoin;
relation.Condition = pairs.Select(a => select.CreateExpression(a)).Merge();
pairs = content.CompositePairs;
}
var target = CreateSource(context, content.TargetSet);
select.AddSource(target);
context.RegisterSource(content.TargetSet, target);
if (content.CompositePairs == null)
{
target.Join = content.Nullable ? EJoinType.LeftJoin : EJoinType.InnerJoin;
}
else
{
target.Join = EJoinType.InnerJoin;
}
target.Condition = pairs.Select(a => select.CreateExpression(a)).Merge();
return(target);
}
}
/// <summary>
/// 根据指定类型<see cref="DbGroupJoinExpression"/>表达式创建数据源语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="expression">指定表达式。</param>
/// <returns>创建结果。</returns>
protected virtual ISourceFragment CreateSourceForGroupJoin(GenerateContext context, DbExpression expression)
{
var content = (DbGroupJoinExpression)expression;
var source = CreateSource(context, content.Source);
var taget = CreateSource(context, content.Target);
var container = new SelectFragment(context, source);
var virtualSource = new VirtualSourceFragment(context, expression, container, source);
context.RegisterSource(content.Item, virtualSource);
if (IsSelectFragment(content))
{
return(InitialSelectFragment(container, content));
}
return(container);
}
/// <summary>
/// 根据指定类型<see cref="DbGroupJoinExpression"/>表达式创建虚拟数据源连接语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="expression">表达式。</param>
/// <param name="source">虚拟数据源</param>
/// <returns>查询语句片段。</returns>
public virtual ISourceFragment CreateVirtualJoinForGroupJoin(GenerateContext context, DbCrossJoinExpression expression, VirtualSourceFragment source)
{
var content = (DbGroupJoinExpression)source.Expression;
var groupset = (DbGroupSetExpression)expression.Target;
var target = GetSource(context, content.Target.Item);
context.RegisterSource(expression.Target.Item, target);
var joinBody = target;
var container = source.Container;
container.AddSource(target);
joinBody.Join = groupset.Default == null ? EJoinType.InnerJoin : EJoinType.LeftJoin;
joinBody.Condition = content.KeyPairs.Select(a => container.CreateExpression(a)).Merge();
return(joinBody);
}
/// <summary>
/// 根据指定类型<see cref="DbCollectionMemberExpression"/>表达式创建虚拟数据源连接语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="expression">表达式。</param>
/// <param name="source">虚拟数据源</param>
/// <returns>查询语句片段。</returns>
public virtual ISourceFragment CreateVirtualJoinForCollectionMember(GenerateContext context, DbCrossJoinExpression expression, VirtualSourceFragment source)
{
var content = (DbCollectionMemberExpression)source.Expression;
var target = GetSource(context, content.TargetSet.Item);
var container = source.Container;
if (content.Metadata.IsComposite)
{
var relationSet = GenerateVirtualCompositeJoinForCollectionMember(context, content, container, false);
relationSet.Join = content.Default == null ? EJoinType.InnerJoin : EJoinType.LeftJoin;
}
container.AddSource(target);
GenerateVirtualJoinForCollectionMember(context, source, target, true);
if (content.Metadata.IsComposite)
{
target.Join = EJoinType.InnerJoin;
}
else
{
target.Join = content.Default == null ? EJoinType.InnerJoin : EJoinType.LeftJoin;
}
context.RegisterSource(content.Item, target);
return(target);
}