/// <summary>
/// replaces selectors (column references) expressions, with an expression that reads the corresponding
/// value from DataReader
/// </summary>
/// <param name="selector"></param>
/// <returns></returns>
public override Expression VisitSelector(SelectorExpression selector)
{
Expression value;
//check if it is a token (of which we don't know it's type)
if (selector.Type == typeof(CqlToken))
return Expression.New(TokenConstructor,
Expression.MakeIndex(_reader, Indexer, new[] { Expression.Constant(selector.Ordinal) }));
//normal case
value = Expression.Call(_reader, "GetFieldValue", new [] { selector.Type }, Expression.Constant(selector.Ordinal));
//check for null values in case of a Nullable type
if (selector.Type.IsGenericType && selector.Type.GetGenericTypeDefinition() == typeof(Nullable<>))
{
value = Expression.Condition(
Expression.Call(_reader, "IsDBNull", null, Expression.Constant(selector.Ordinal)),
Expression.Constant(null, selector.Type),
Expression.Convert(value, selector.Type)
);
}
return value;
}
public OrderingExpression(SelectorExpression selector, CqlExpressionType orderType)
{
if (selector == null)
throw new ArgumentNullException("selector");
if (orderType != CqlExpressionType.OrderAscending && orderType != CqlExpressionType.OrderDescending)
throw new ArgumentException("ExpressionType must be OrderAscending or OrderDescending", "orderType");
_selector = selector;
_order = orderType;
}
/// <summary>
/// Initializes a new instance of the <see cref="RelationExpression" /> class.
/// </summary>
/// <param name="selector"> The selector. </param>
/// <param name="relation"> The relation. </param>
/// <param name="term"> The term. </param>
/// <exception cref="System.ArgumentNullException">selector
/// or
/// term</exception>
public RelationExpression(SelectorExpression selector, CqlExpressionType relation, TermExpression term)
{
if (selector == null) throw new ArgumentNullException("selector");
if (term == null)
throw new ArgumentNullException("term");
_selector = selector;
_relation = relation;
_term = term;
}
protected override Expression VisitChildren(ExpressionVisitor visitor)
{
if (_selectors != null)
{
bool changed = false;
int count = _selectors.Count;
var selectors = new SelectorExpression[count];
for (int i = 0; i < count; i++)
{
selectors[i] = (SelectorExpression) visitor.Visit(_selectors[i]);
changed |= selectors[i] != _selectors[i];
}
if (changed)
{
return new SelectClauseExpression(selectors, _distinct);
}
}
return this;
}
public override Expression VisitSelector(SelectorExpression selector)
{
_selectors.Add(selector);
return selector;
}
public override Expression VisitSelector(SelectorExpression selector)
{
base.VisitSelector(selector);
string value;
switch ((CqlExpressionType)selector.NodeType)
{
case CqlExpressionType.IdentifierSelector:
value = "\"" + selector.Identifier.Replace("\"", "\"\"") + "\"";
break;
case CqlExpressionType.FunctionSelector:
var builder = new StringBuilder();
builder.Append(selector.Function.Name.ToLower());
builder.Append("(");
var argsAsString = selector.Arguments.Select(arg => _translations[arg]);
builder.Append(string.Join(",", argsAsString));
builder.Append(")");
value = builder.ToString();
break;
default:
throw new CqlLinqException("Unexpected Selector type encountered");
}
_translations[selector] = value;
return selector;
}
public virtual Expression VisitSelector(SelectorExpression selector)
{
return base.VisitExtension(selector);
}
/// <summary>
/// replaces selectors (column references) expressions, with an expression that reads the corresponding
/// value from DataReader
/// </summary>
/// <param name="selector"></param>
/// <returns></returns>
public override Expression VisitSelector(SelectorExpression selector)
{
Expression value;
//check if it is a token (of which we don't know it's type)
if (selector.Type == typeof(CqlToken))
return Expression.New(TokenConstructor,
Expression.MakeIndex(_reader, Indexer, new[] { Expression.Constant(selector.Ordinal) }));
switch (selector.Type.ToCqlType())
{
case CqlType.Set:
value = Expression.Call(_reader,
"GetSet",
new[] { TypeSystem.GetElementType(selector.Type) },
Expression.Constant(selector.Ordinal));
break;
case CqlType.List:
value = Expression.Call(_reader,
"GetList",
selector.Type.GetGenericArguments(),
Expression.Constant(selector.Ordinal));
break;
case CqlType.Map:
value = Expression.Call(_reader,
"GetDictionary",
selector.Type.GetGenericArguments(),
Expression.Constant(selector.Ordinal));
break;
case CqlType.Varchar:
case CqlType.Text:
case CqlType.Ascii:
value = Expression.Call(_reader,
"GetString",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Int:
value = Expression.Call(_reader,
"GetInt32",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Counter:
case CqlType.Bigint:
value = Expression.Call(_reader,
"GetInt64",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Varint:
value = Expression.Call(_reader,
"GetBigInteger",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Blob:
value = Expression.Call(_reader,
"GetBytes",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Boolean:
value = Expression.Call(_reader,
"GetBoolean",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Decimal:
value = Expression.Call(_reader,
"GetDecimal",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Double:
value = Expression.Call(_reader,
"GetDouble",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Float:
value = Expression.Call(_reader,
"GetFloat",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Inet:
value = Expression.Call(_reader,
"GetIPAddress",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Timestamp:
value = Expression.Call(_reader,
"GetDateTime",
null,
Expression.Constant(selector.Ordinal));
break;
case CqlType.Uuid:
case CqlType.Timeuuid:
value = Expression.Call(_reader,
"GetGuid",
null,
Expression.Constant(selector.Ordinal));
break;
default:
value = Expression.Convert(
Expression.MakeIndex(_reader, Indexer, new[] { Expression.Constant(selector.Ordinal) }),
selector.Type);
break;
}
//check for null values in case of a Nullable type
if (selector.Type.IsGenericType && selector.Type.GetGenericTypeDefinition() == typeof(Nullable<>))
{
value = Expression.Condition(
Expression.Call(_reader, "IsDBNull", null, Expression.Constant(selector.Ordinal)),
Expression.Constant(null, selector.Type),
Expression.Convert(value, selector.Type)
);
}
return value;
}