protected override void VisitProperty(PropertyConstraint node)
{
var op = ConvertOperator(node.Operator);
var source = Query.From.FindTable(node.ConcreteType);
var column = source.Column(node.Property);
_whereResult = f.Constraint(column, op, node.Value);
}
private IConstraint CreateColumnConstraint(string comparison, string value)
{
var op = PropertyOperator.Equal;
switch (comparison.ToLower())
{
case "eq":
op = PropertyOperator.Equal;
break;
case "ne":
op = PropertyOperator.NotEqual;
break;
case "gt":
op = PropertyOperator.Greater;
break;
case "ge":
op = PropertyOperator.GreaterEqual;
break;
case "lt":
op = PropertyOperator.Less;
break;
case "le":
op = PropertyOperator.LessEqual;
break;
case "contains":
op = PropertyOperator.Contains;
break;
case "startswith":
op = PropertyOperator.StartsWith;
break;
case "endswith":
op = PropertyOperator.EndsWith;
break;
case "notcontains":
op = PropertyOperator.NotContains;
break;
case "notstartswith":
op = PropertyOperator.NotStartsWith;
break;
case "notendswith":
op = PropertyOperator.NotEndsWith;
break;
default:
throw new NotSupportedException("不支持这个操作符：" + comparison + "。");
}
return(_f.Constraint(_column, op, value));
}
/// <summary>
/// 通过目前已经收集到的属性、操作符、值，来生成一个属性条件结果。
/// 并清空已经收集的信息。
/// </summary>
private void MakeConstraint()
{
if (_propertyResult != null && _operator.HasValue)
{
if (_hasValueResult)
{
_query.Where = f.Constraint(_propertyResult, _operator.Value, _valueResult);
_hasValueResult = false;
}
else
{
_query.Where = f.Constraint(_propertyResult, _operator.Value, _rightPropertyResult);
_rightPropertyResult = null;
}
_propertyResult = null;
_operator = null;
}
}
/// <summary>
/// 通过目前已经收集到的属性、操作符、值，来生成一个属性条件结果。
/// 并清空已经收集的信息。
/// </summary>
private bool MakeConstraint()
{
if (_propertyResult != null && _operator.HasValue)
{
var op = _operator.Value;
if (_reverseWhere)
{
op = PropertyOperatorHelper.Reverse(op);
}
if (_hasValueResult)
{
_constraintResult = f.Constraint(_propertyResult, op, _valueResult);
_valueResult = null;
_hasValueResult = false;
}
else
{
_constraintResult = f.Constraint(_propertyResult, op, _rightPropertyResult);
_rightPropertyResult = null;
}
_propertyResult = null;
_operator = null;
}
if (_constraintResult != null)
{
if (_nullableRefConstraint != null)
{
var concat = _reverseWhere ? BinaryOperator.Or : BinaryOperator.And;
_constraintResult = f.Binary(_nullableRefConstraint, concat, _constraintResult);
_nullableRefConstraint = null;
}
_query.Where = _constraintResult;
_constraintResult = null;
return(true);
}
return(false);
}
protected override Expression VisitMethodCall(MethodCallExpression exp)
{
var method = exp.Method;
_isAny = method.Name == LinqConsts.EnumerableMethod_Any;
//先访问表达式 book.ChapterList.Cast<Chapter>()，获取列表属性。
var invoker = exp.Arguments[0];
_parentPropertyFinder.Find(invoker);
var listPropertyTable = _parentPropertyFinder.PropertyOwnerTable;
var listProperty = _parentPropertyFinder.Property as IListProperty;
if (listProperty == null)
{
throw EntityQueryBuilder.OperationNotSupported(invoker);
}
//为该列表对应的实体创建表对象、查询对象。
var childRepo = RepositoryFactoryHost.Factory.FindByEntity(listProperty.ListEntityType);
var childTable = f.Table(childRepo);
_query = f.Query(
from: childTable,
selection: f.Literal("1")
);
var qgc = QueryGenerationContext.Get(_parentQuery);
qgc.Bind(_query);
childTable.Alias = qgc.NextTableAlias();
//Any、All 方法如果有第二个参数，那么第二个参数就是条件表达式。如：c => c.Name == chapterName
if (exp.Arguments.Count == 2)
{
var reverseWhere = !_isAny;//如果是 All，则需要反转里面的所有操作符。
var queryBuilder = new EntityQueryBuilder(childRepo, reverseWhere);
queryBuilder.BuildQuery(exp.Arguments[1], _query);
}
//添加子表查询与父实体的关系条件：WHERE c.BookId = b.Id
var parentProperty = childRepo.FindParentPropertyInfo(true);
var parentRefIdProperty = (parentProperty.ManagedProperty as IRefProperty).RefIdProperty;
var toParentConstraint = f.Constraint(childTable.Column(parentRefIdProperty), listPropertyTable.IdColumn);
_query.Where = f.And(toParentConstraint, _query.Where);
return(exp);
}
private IConstraint CreatePropertyConstraint(string property, string comparison, string value)
{
var mp = _properties.Find(property, true);
if (mp == null)
{
throw new InvalidProgramException(string.Format("查询条件解析出错，没有找到名称为 {0} 的属性。", property));
}
var column = _mainTable.Column(mp);
var op = PropertyOperator.Equal;
switch (comparison.ToLower())
{
case "eq":
op = PropertyOperator.Equal;
break;
case "ne":
op = PropertyOperator.NotEqual;
break;
case "gt":
op = PropertyOperator.Greater;
break;
case "ge":
op = PropertyOperator.GreaterEqual;
break;
case "lt":
op = PropertyOperator.Less;
break;
case "le":
op = PropertyOperator.LessEqual;
break;
default:
throw new NotSupportedException("不支持这个操作符：" + comparison + "。");
}
return(_f.Constraint(column, op, value));
}
private IConstraint CreateColumnConstraint(string comparison, string value)
{
#region 转换操作符
var op = PropertyOperator.Equal;
switch (comparison.ToLower())
{
case "eq":
op = PropertyOperator.Equal;
break;
case "ne":
op = PropertyOperator.NotEqual;
break;
case "gt":
op = PropertyOperator.Greater;
break;
case "ge":
op = PropertyOperator.GreaterEqual;
break;
case "lt":
op = PropertyOperator.Less;
break;
case "le":
op = PropertyOperator.LessEqual;
break;
case "contains":
op = PropertyOperator.Contains;
break;
case "startswith":
op = PropertyOperator.StartsWith;
break;
case "endswith":
op = PropertyOperator.EndsWith;
break;
case "notcontains":
op = PropertyOperator.NotContains;
break;
case "notstartswith":
op = PropertyOperator.NotStartsWith;
break;
case "notendswith":
op = PropertyOperator.NotEndsWith;
break;
default:
throw new NotSupportedException("不支持这个操作符：" + comparison + "。");
}
#endregion
#region 把表达式中的值转换为列的类型对应的值。（同时，兼容处理枚举的 Label 值。）
object columnValue = null;
var propertyType = _column.Property.PropertyType;
var innerType = TypeHelper.IgnoreNullable(propertyType);
if (innerType.IsEnum)
{
columnValue = EnumViewModel.LabelToEnum(value, innerType);
}
else
{
columnValue = TypeHelper.CoerceValue(_column.Property.PropertyType, value);
}
#endregion
return(_f.Constraint(_column, op, columnValue));
}
