static string Equals(Field field, object value, bool equals)
{
if (value == null)
{
return IsNull(field, equals);
}
else
{
if (field is IColumn)
{
return ((IColumn)field).Name.SqlEscape() +
(equals ? " = " : " <> ") + SqlPreCommandSimple.Encode(value);
}
throw new NotSupportedException("Impossible to compare {0} to {1}".FormatWith(field, value));
}
}
static bool IsComplexIB(Field field)
{
return field is FieldImplementedBy && ((FieldImplementedBy)field).ImplementationColumns.Count > 1;
}
public static string IsNull(Field field, bool equals)
{
string isNull = equals ? "{0} IS NULL" : "{0} IS NOT NULL";
if (field is IColumn)
{
var col = ((IColumn)field);
string result = isNull.FormatWith(col.Name.SqlEscape());
if (!SqlBuilder.IsString(col.SqlDbType))
return result;
return result + (equals ? " OR " : " AND ") + (col.Name.SqlEscape() + (equals ? " == " : " <> ") + "''");
}
else if (field is FieldImplementedBy)
{
var ib = (FieldImplementedBy)field;
return ib.ImplementationColumns.Values.Select(ic => isNull.FormatWith(ic.Name.SqlEscape())).ToString(equals ? " AND " : " OR ");
}
else if (field is FieldImplementedByAll)
{
var iba = (FieldImplementedByAll)field;
return isNull.FormatWith(iba.Column.Name.SqlEscape()) +
(equals ? " AND " : " OR ") +
isNull.FormatWith(iba.ColumnType.Name.SqlEscape());
}
else if (field is FieldEmbedded)
{
var fe = (FieldEmbedded)field;
if (fe.HasValue == null)
throw new NotSupportedException("{0} is not nullable".FormatWith(field));
return fe.HasValue.Name.SqlEscape() + " = TRUE";
}
throw new NotSupportedException(isNull.FormatWith(field.GetType()));
}