/// <summary>
/// Returns a locator for the member being queried upon
/// </summary>
/// <param name="mapping"></param>
/// <param name="expression"></param>
/// <returns></returns>
protected virtual string GetLocator(IDocumentMapping mapping, MethodCallExpression expression)
{
if (!expression.Method.IsStatic && expression.Object != null && expression.Object.NodeType != ExpressionType.Constant)
{
// x.member.Equals(...)
return mapping.JsonLocator(expression.Object);
}
if (expression.Arguments[0].NodeType == ExpressionType.Constant)
{
// string.Equals("value", x.member)
return mapping.JsonLocator(expression.Arguments[1]);
}
// string.Equals(x.member, "value")
return mapping.JsonLocator(expression.Arguments[0]);
}
private IWhereFragment buildSimpleWhereClause(IDocumentMapping mapping, BinaryExpression binary)
{
var isValueExpressionOnRight = binary.Right.IsValueExpression();
var jsonLocatorExpression = isValueExpressionOnRight ? binary.Left : binary.Right;
var valuExpression = isValueExpressionOnRight ? binary.Right : binary.Left;
var op = _operators[binary.NodeType];
var value = valuExpression.Value();
if (mapping.PropertySearching == PropertySearching.ContainmentOperator &&
binary.NodeType == ExpressionType.Equal && value != null)
{
return new ContainmentWhereFragment(_serializer, binary);
}
var jsonLocator = mapping.JsonLocator(jsonLocatorExpression);
if (value == null)
{
var sql = binary.NodeType == ExpressionType.NotEqual
? $"({jsonLocator}) is not null"
: $"({jsonLocator}) is null";
return new WhereFragment(sql);
}
if (jsonLocatorExpression.NodeType == ExpressionType.Modulo)
{
var moduloByValue = GetModuloByValue(binary);
return new WhereFragment("{0} % {1} {2} ?".ToFormat(jsonLocator, moduloByValue, op), value);
}
return new WhereFragment("{0} {1} ?".ToFormat(jsonLocator, op), value);
}