private string SimplifyConstantExpression(QueryParts query, SubqueryParts parts, string exp, ConstantExpression ce)
{
if (ce.Type.IsArray || ce.Value is Array)
{
var array = ((Array)ce.Value).Cast<object>().ToArray();
return FormatInQuery(exp, array, parts);
}
else if (ce.Value is IEnumerable)
{
var array = ((IEnumerable)ce.Value).Cast<object>().ToArray();
return FormatInQuery(exp, array, parts);
}
return exp + " = " + query.FormatObject(ce.Value);
}
public static SelectSubqueryData Create(QueryParts parts, SubqueryParts subquery)
{
Contract.Requires(parts != null);
Contract.Requires(subquery != null);
var selects = new List<KeyValuePair<IQuerySource, Func<object, object>>>();
foreach (var s in subquery.Selects)
{
var factory = QuerySourceConverterFactory.Create(s.QuerySource, parts);
selects.Add(new KeyValuePair<IQuerySource, Func<object, object>>(factory.QuerySource, factory.Instancer));
}
return new SelectSubqueryData(selects);
}
private string FormatInQuery(string exp, object[] array, SubqueryParts query)
{
if (array.Length == 0)
return "false";
if (array.Length == 1 && array[0] == null)
return exp + " IS NULL ";
var qsre = query.Selector as QuerySourceReferenceExpression;
if (qsre != null && qsre.ReferencedQuerySource.Equals(query.MainFrom)
&& NpgsqlTypes.TypeConverter.CanConvert(query.MainFrom.ItemType))
{
return array.Length == 1
? exp + " = " + NpgsqlTypes.TypeConverter.Convert(query.MainFrom.ItemType, array[0])
: exp + " IN ("
+ string.Join(
",",
array.Select(it => NpgsqlTypes.TypeConverter.Convert(query.MainFrom.ItemType, it)))
+ ")";
}
return exp + " IN (SELECT " + query.GetSqlExpression(query.Selector)
+ " FROM unnest(" + query.FormatArray(array) + ") \"" + query.MainFrom.ItemName + "\")";
}
private SubqueryGeneratorQueryModelVisitor(QueryParts parentQuery, bool canQueryInMemory, Expression selector, string contextName)
{
QueryParts = new SubqueryParts(parentQuery, canQueryInMemory, selector, contextName);
}
private string SimplifyMemberExpression(QueryParts query, SubqueryParts parts, string exp, MemberExpression ma)
{
return exp + " IN (SELECT " + query.GetSqlExpression(parts.Selector)
+ " FROM unnest(" + query.GetSqlExpression(ma) + ") \"" + query.MainFrom.ItemName + "\")";
}
