/// <inheritdoc />
protected override void VisitCore(MethodCallExpression node)
{
string name = node.Method.Name;
if (isNoPackage)
{
switch (name)
{
case MethodCall.TimeOut:
case MethodCall.From:
case MethodCall.Any:
case MethodCall.All:
case MethodCall.Contains:
case MethodCall.Union:
case MethodCall.Concat:
case MethodCall.Except:
case MethodCall.Intersect:
break;
default:
isNoPackage = false;
break;
}
}
switch (name)
{
case MethodCall.ElementAt:
case MethodCall.ElementAtOrDefault:
base.Visit(node.Arguments[0]);
int index = (int)node.Arguments[1].GetValueFromExpression();
if (index < 0)
{
throw new IndexOutOfRangeException();
}
if (this.take > 0 && index < this.take)
{
throw new IndexOutOfRangeException();
}
this.take = 1;
this.skip += index;
break;
case MethodCall.Take:
case MethodCall.TakeLast:
if (useAggregation)
{
throw new DSyntaxErrorException($"使用聚合函数时，禁止使用分页函数({name})!");
}
if (name == MethodCall.TakeLast)
{
reverseOrder ^= true;
}
int take = (int)node.Arguments[1].GetValueFromExpression();
if (take < 1)
{
throw new ArgumentOutOfRangeException($"使用{name}函数,参数值必须大于零!");
}
if (this.take > 0 && take < this.take)
{
throw new IndexOutOfRangeException();
}
if (this.skip > -1)
{
if (this.skip > take)
{
throw new IndexOutOfRangeException();
}
take -= this.skip;
}
if (this.take == -1)
{
this.take = take;
}
base.Visit(node.Arguments[0]);
if (!useOrderBy && name == MethodCall.TakeLast)
{
throw new DSyntaxErrorException($"使用函数({name})时，必须使用排序函数(OrderBy/OrderByDescending)!");
}
break;
case MethodCall.First:
case MethodCall.FirstOrDefault:
case MethodCall.Single:
case MethodCall.SingleOrDefault:
// TOP(1)
this.take = 1;
if (node.Arguments.Count > 1)
{
VisitCondition(node);
}
else
{
Visit(node.Arguments[0]);
}
break;
case MethodCall.Last:
case MethodCall.LastOrDefault:
// TOP(..)
this.take = 1;
reverseOrder ^= true;
if (node.Arguments.Count > 1)
{
VisitCondition(node);
}
else
{
base.Visit(node.Arguments[0]);
}
if (!useOrderBy)
{
throw new DSyntaxErrorException($"使用函数({name})时，必须使用排序函数(OrderBy/OrderByDescending)!");
}
break;
case MethodCall.Max:
buildSelect = false;
buildedSelect = true;
useAggregation = true;
using (var visitor = new MaxVisitor(this))
{
visitor.Startup(node);
}
break;
case MethodCall.Min:
buildSelect = false;
buildedSelect = true;
useAggregation = true;
using (var visitor = new MinVisitor(this))
{
visitor.Startup(node);
}
break;
case MethodCall.Sum:
buildSelect = false;
buildedSelect = true;
useAggregation = true;
using (var visitor = new SumVisitor(this))
{
visitor.Startup(node);
}
break;
case MethodCall.Average:
buildSelect = false;
buildedSelect = true;
useAggregation = true;
using (var visitor = new AverageVisitor(this))
{
visitor.Startup(node);
}
break;
case MethodCall.Count:
case MethodCall.LongCount:
useCount = true;
buildSelect = false;
buildedSelect = true;
useAggregation = true;
using (var visitor = new CountVisitor(this))
{
visitor.Startup(node);
}
break;
case MethodCall.Skip:
case MethodCall.SkipLast:
if (useAggregation)
{
throw new DSyntaxErrorException($"使用聚合函数时，禁止使用分页函数({name})!");
}
if (name == MethodCall.SkipLast)
{
reverseOrder ^= true;
}
int skip = (int)node.Arguments[1].GetValueFromExpression();
if (skip < 0)
{
throw new ArgumentOutOfRangeException($"使用({name})函数,参数值不能小于零!");
}
if (this.skip == -1)
{
this.skip = skip;
}
else
{
this.skip += skip;
}
base.Visit(node.Arguments[0]);
if (!useOrderBy && name == MethodCall.SkipLast)
{
throw new DSyntaxErrorException($"使用函数({name})时，必须使用排序函数(OrderBy/OrderByDescending)!");
}
break;
case MethodCall.Reverse:
reverseOrder ^= true;
base.Visit(node.Arguments[0]);
if (!useOrderBy)
{
throw new DSyntaxErrorException($"使用函数“{name}”时，必须使用排序函数(OrderBy/OrderByDescending)!");
}
break;
case MethodCall.GroupBy:
case MethodCall.Where when node.Arguments[0].Type.IsGroupingQueryable():
case MethodCall.TakeWhile when node.Arguments[0].Type.IsGroupingQueryable():
case MethodCall.SkipWhile when node.Arguments[0].Type.IsGroupingQueryable():
if (name == MethodCall.GroupBy)
{
castCache.Add(node.Type.GetGenericArguments().First(), TypeToEntryType(node.Arguments[0].Type));
}
if (!useGroupBy)
{
byVisitor = new GroupByVisitor(this, defaultCache, groupByExpressions);
}
useGroupBy = true;
byVisitor.Startup(node);
break;
case MethodCall.Select:
if (useCount)
{
base.Visit(node.Arguments[0]);
break;
}
if (!buildSelect)
{
throw new DSyntaxErrorException($"请将函数“{name}”置于查询最后一个包含入参的函数之后!");
}
buildSelect = buildFrom = false;
writer.Select();
Workflow(() =>
{
buildedSelect = true;
if (isDistinct)
{
writer.Distinct();
}
inSelect = true;
Visit(node.Arguments[1]);
inSelect = false;
writer.From();
if (!hasJoin && !hasCombination)
{
WriteTableName(node.Arguments[0].Type);
}
}, () => base.Visit(node.Arguments[0]));
break;
case MethodCall.SelectMany when node.Arguments.Count == 3:
hasJoin = true;
var parameterExp = Join(node.Arguments[2], true);
bool DoneLeftJoin(ParameterExpression parameter, Expression expression)
{
if (expression.NodeType == ExpressionType.MemberAccess)
{
return(false);
}
switch (expression)
{
case UnaryExpression unary:
return(DoneLeftJoin(parameter, unary.Operand));
case LambdaExpression lambda when lambda.Parameters.Count == 1:
return(DoneLeftJoin(parameter, lambda.Body));
case MethodCallExpression methodCall when methodCall.Method.Name == MethodCall.DefaultIfEmpty:
if (methodCall.Arguments.Count > 1)
{
defaultCache.Add(Tuple.Create(parameter.Type, parameter.Name), methodCall.Arguments[1]);
}
return(true);
default:
throw new DSyntaxErrorException();
}
}
using (var visitor = new GroupJoinVisitor(this, parameterExp, DoneLeftJoin(parameterExp, node.Arguments[1])))
{
visitor.Startup(node.Arguments[0]);
}
buildTable = false;
break;
case MethodCall.Distinct:
if (buildedSelect)
{
throw new DSyntaxErrorException($"函数“{name}”未生效！");
}
isDistinct = true;
base.Visit(node.Arguments[0]);
break;
case MethodCall.Cast:
case MethodCall.OfType:
Type type = node.Type
.GetGenericArguments()
.First();
if (type.IsValueType || type == typeof(string) || typeof(IEnumerable).IsAssignableFrom(type))
{
throw new TypeAccessInvalidException($"“{node.Method.Name}”函数泛型参数类型不能是值类型、字符串类型或迭代类型!");
}
var objExp = node.Arguments[0];
var originalType = objExp.Type;
if (node.Type == originalType)
{
base.Visit(objExp);
break;
}
useCast = true;
if (!castCache.ContainsKey(type))
{
castCache.Add(type, TypeToEntryType(originalType));
}
var entry = TypeItem.Get(type);
if (memberFilters.Count == 0)
{
memberFilters.AddRange(entry.PropertyStores
.Where(x => x.CanRead && x.CanWrite)
.Select(x => x.Name.ToLower()));
}
else //? 取交集
{
memberFilters = memberFilters
.Intersect(entry.PropertyStores
.Where(x => x.CanRead && x.CanWrite)
.Select(x => x.Name.ToLower()))
.ToList();
}
if (memberFilters.Count == 0)
{
throw new DException("未指定查询字段!");
}
base.Visit(objExp);
break;
case MethodCall.OrderBy:
case MethodCall.ThenBy:
case MethodCall.OrderByDescending:
case MethodCall.ThenByDescending:
useOrderBy = true;
if (useAggregation)
{
base.Visit(node.Arguments[0]);
break;
}
bool thatReverseOrder = reverseOrder;
Workflow(() => writer.UsingSort(() =>
{
orderBySwitch.OrderBy();
base.Visit(node.Arguments[1]);
if (thatReverseOrder ^ node.Method.Name.EndsWith("Descending"))
{
writer.Descending();
}
}), () => base.Visit(node.Arguments[0]));
break;
case MethodCall.Join:
hasJoin = true;
Join(node.Arguments[2], false);
Join(node.Arguments[3], true);
using (var visitor = new JoinVisitor(this))
{
visitor.Startup(node);
}
buildTable = false;
break;
case MethodCall.Any:
isExists = true;
using (var visitor = new AnyVisitor(this))
{
visitor.Startup(node);
}
break;
case MethodCall.All:
isExists = true;
using (var visitor = new AllVisitor(this))
{
visitor.Startup(node);
}
break;
case MethodCall.Union:
case MethodCall.Concat:
case MethodCall.Except:
case MethodCall.Intersect:
buildTable = buildFrom = false;
hasCombination = true;
if (isNoPackage)
{
buildSelect = false;
buildedSelect = true;
using (var visitor = new CombinationVisitor(this))
{
visitor.Startup(node);
}
break;
}
string prefix = "x";
if (buildSelect)
{
buildSelect = false;
var tableInfo = MakeTableInfo(node.Arguments[0].Type);
Workflow(() =>
{
buildedSelect = true;
writer.Select();
if (isDistinct)
{
writer.Distinct();
}
WriteMembers(prefix, FilterMembers(tableInfo.ReadOrWrites));
}, Done);
break;
}
Done();
break;
void Done()
{
writer.From();
writer.OpenBrace();
using (var visitor = new CombinationVisitor(this))
{
visitor.Startup(node);
}
writer.CloseBrace();
writer.WhiteSpace();
writer.Name(prefix = GetEntryAlias(node.Arguments[0].Type, "x"));
}
default:
base.VisitCore(node);
break;
}
ParameterExpression Join(Expression expression, bool isJoin)
{
switch (expression)
{
case UnaryExpression unary:
return(Join(unary.Operand, isJoin));
case LambdaExpression lambda when lambda.Parameters.Count == 1 || lambda.Parameters.Count == 2:
#if NETSTANDARD2_1_OR_GREATER
var parameter = lambda.Parameters[^ 1];
/// <inheritdoc />
public HavingVisitor(GroupByVisitor visitor, Dictionary <MemberInfo, Expression> groupByExpressions) : base(visitor)
{
this.visitor = visitor;
this.groupByExpressions = groupByExpressions;
}