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# File 'lib/proximal_records/adapters/mysql2.rb', line 4
def proximal_records(scope)
klass = self.class
z = klass.select("#{klass.table_name}.*, IF(rownum < @num, 'previous', 'next') AS direction, rownum").arel
t = klass.select("z.*, @rownum := @rownum + 1 AS rownum, CASE WHEN z.id = #{id} THEN @num := @rownum END").arel
t.join(Arel.sql('JOIN (SELECT @rownum := 0, @num := NULL) n'))
t.from("(#{scope.to_sql}) z")
z.from("(#{t.to_sql}) #{klass.table_name}")
sql = z.where(Arel.sql('rownum > @num - 2 AND rownum < @num + 2 AND rownum <> @num')).to_sql
items = klass.find_by_sql(sql)
if items[0]
if items[0].direction == 'previous'
[items[0], items[1]]
else
[nil, items[0]]
end
else
[nil, nil]
end
end
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