/** <inheritdoc /> */
protected override Expression VisitQuerySourceReference(QuerySourceReferenceExpression expression)
{
// In some cases of Join clause different handling should be introduced
var joinClause = expression.ReferencedQuerySource as JoinClause;
if (joinClause != null && ExpressionWalker.GetCacheQueryable(expression, false) == null)
{
var tableName = Aliases.GetTableAlias(expression);
var fieldname = Aliases.GetFieldAlias(expression);
ResultBuilder.AppendFormat("{0}.{1}", tableName, fieldname);
}
else if (joinClause != null && joinClause.InnerSequence is SubQueryExpression)
{
var subQueryExpression = (SubQueryExpression)joinClause.InnerSequence;
base.Visit(subQueryExpression.QueryModel.SelectClause.Selector);
}
else
{
// Count, sum, max, min expect a single field or *
// In other cases we need both parts of cache entry
var format = _includeAllFields
? "{0}.*, {0}._KEY, {0}._VAL"
: _useStar
? "{0}.*"
: "{0}._KEY, {0}._VAL";
var tableName = Aliases.GetTableAlias(expression);
ResultBuilder.AppendFormat(format, tableName);
}
return(expression);
}
protected override Expression VisitMember(MemberExpression expression)
{
// Field hierarchy is flattened (Person.Address.Street is just Street), append as is, do not call Visit.
// Property call (string.Length, DateTime.Month, etc).
if (MethodVisitor.VisitPropertyCall(expression, this))
{
return(expression);
}
// Special case: grouping
if (VisitGroupByMember(expression.Expression))
{
return(expression);
}
var queryable = ExpressionWalker.GetCacheQueryable(expression, false);
if (queryable != null)
{
// Find where the projection comes from.
expression = ExpressionWalker.GetProjectedMember(expression.Expression, expression.Member) ??
expression;
var fieldName = GetEscapedFieldName(expression, queryable);
ResultBuilder.AppendFormat("{0}.{1}", Aliases.GetTableAlias(expression), fieldName);
}
else
{
AppendParameter(ExpressionWalker.EvaluateExpression <object>(expression));
}
return(expression);
}
public override void VisitJoinClause(JoinClause joinClause, QueryModel queryModel, int index)
{
base.VisitJoinClause(joinClause, queryModel, index);
var subQuery = joinClause.InnerSequence as SubQueryExpression;
if (subQuery != null)
{
var isOuter = subQuery.QueryModel.ResultOperators.OfType <DefaultIfEmptyResultOperator>().Any();
_builder.AppendFormat("{0} join (", isOuter ? "left outer" : "inner");
VisitQueryModel(subQuery.QueryModel, true);
var alias = _aliases.GetTableAlias(subQuery.QueryModel.MainFromClause);
_builder.AppendFormat(") as {0} on (", alias);
}
else
{
var queryable = ExpressionWalker.GetCacheQueryable(joinClause);
var tableName = ExpressionWalker.GetTableNameWithSchema(queryable);
var alias = _aliases.GetTableAlias(joinClause);
_builder.AppendFormat("inner join {0} as {1} on (", tableName, alias);
}
BuildJoinCondition(joinClause.InnerKeySelector, joinClause.OuterKeySelector);
_builder.Append(") ");
}
/// <summary>
/// Appends as clause.
/// </summary>
public StringBuilder AppendAsClause(StringBuilder builder, IFromClause clause)
{
Debug.Assert(builder != null);
Debug.Assert(clause != null);
var queryable = ExpressionWalker.GetCacheQueryable(clause);
var tableName = ExpressionWalker.GetTableNameWithSchema(queryable);
builder.AppendFormat("{0} as {1}", tableName, GetTableAlias(clause));
return(builder);
}
/** <inheritdoc /> */
protected override Expression VisitQuerySourceReference(QuerySourceReferenceExpression expression)
{
// Count, sum, max, min expect a single field or *
// In other cases we need both parts of cache entry
var format = _useStar ? "{0}.*" : "{0}._key, {0}._val";
var tableName = Aliases.GetTableAlias(ExpressionWalker.GetCacheQueryable(expression));
ResultBuilder.AppendFormat(format, tableName);
return(expression);
}
/// <summary>
/// Visits IEnumerable.Contains
/// </summary>
private void VisitContains(QueryModel subQueryModel, ContainsResultOperator contains)
{
ResultBuilder.Append('(');
var fromExpression = subQueryModel.MainFromClause.FromExpression;
var queryable = ExpressionWalker.GetCacheQueryable(fromExpression, false);
if (queryable != null)
{
Visit(contains.Item);
ResultBuilder.Append(" IN (");
if (_visitEntireSubQueryModel)
{
_modelVisitor.VisitQueryModel(subQueryModel, false, true);
}
else
{
_modelVisitor.VisitQueryModel(subQueryModel);
}
ResultBuilder.Append(')');
}
else
{
var inValues = ExpressionWalker.EvaluateEnumerableValues(fromExpression).ToArray();
var hasNulls = inValues.Any(o => o == null);
if (hasNulls)
{
ResultBuilder.Append('(');
}
Visit(contains.Item);
ResultBuilder.Append(" IN (");
AppendInParameters(inValues);
ResultBuilder.Append(')');
if (hasNulls)
{
ResultBuilder.Append(") OR ");
Visit(contains.Item);
ResultBuilder.Append(" IS NULL");
}
}
ResultBuilder.Append(')');
}
public override void VisitJoinClause(JoinClause joinClause, QueryModel queryModel, int index)
{
base.VisitJoinClause(joinClause, queryModel, index);
var subQuery = joinClause.InnerSequence as SubQueryExpression;
if (subQuery != null)
{
var isOuter = subQuery.QueryModel.ResultOperators.OfType <DefaultIfEmptyResultOperator>().Any();
_builder.AppendFormat("{0} join (", isOuter ? "left outer" : "inner");
VisitQueryModel(subQuery.QueryModel, true);
var queryable = ExpressionWalker.GetCacheQueryable(subQuery.QueryModel.MainFromClause);
var alias = _aliases.GetTableAlias(queryable);
_builder.AppendFormat(") as {0} on (", alias);
}
else
{
var innerExpr = joinClause.InnerSequence as ConstantExpression;
if (innerExpr == null)
{
throw new NotSupportedException("Unexpected JOIN inner sequence (subqueries are not supported): " +
joinClause.InnerSequence);
}
if (!(innerExpr.Value is ICacheQueryable))
{
throw new NotSupportedException("Unexpected JOIN inner sequence " +
"(only results of cache.ToQueryable() are supported): " +
innerExpr.Value);
}
var queryable = ExpressionWalker.GetCacheQueryable(joinClause);
var tableName = ExpressionWalker.GetTableNameWithSchema(queryable);
_builder.AppendFormat("inner join {0} as {1} on (", tableName, _aliases.GetTableAlias(tableName));
}
BuildJoinCondition(joinClause.InnerKeySelector, joinClause.OuterKeySelector);
_builder.Append(") ");
}
protected override Expression VisitMember(MemberExpression expression)
{
// Field hierarchy is flattened (Person.Address.Street is just Street), append as is, do not call Visit.
// Special case: string.Length
if (expression.Member == MethodVisitor.StringLength)
{
ResultBuilder.Append("length(");
VisitMember((MemberExpression)expression.Expression);
ResultBuilder.Append(")");
return(expression);
}
// Special case: grouping
if (VisitGroupByMember(expression.Expression))
{
return(expression);
}
var queryable = ExpressionWalker.GetCacheQueryable(expression, false);
if (queryable != null)
{
var fieldName = GetFieldName(expression, queryable);
ResultBuilder.AppendFormat("{0}.{1}", Aliases.GetTableAlias(expression), fieldName);
}
else
{
AppendParameter(RegisterEvaluatedParameter(expression));
}
return(expression);
}
