escaping - Escape string gets un-escaped in mysql concat function -

i have following sp:

create procedure sp_test (     text_data varchar(50) ) begin     set @var_query = concat('select * sample_table col="',text_data,'"');     prepare stmt @var_query;     execute stmt;     deallocate prepare stmt; end; 

i call sp call sp_test('screen size 4.3\"'). error. if check value of @var_query variable, how looks.

+-------------------------------------------------------+ | @var_query                                            | +-------------------------------------------------------+ | select sample_table col="screen size 4.3"" | +-------------------------------------------------------+ 

as can see escaped " getting un-escaped. if hit select statement directly escaped double-quotes, runs fine. means concat removing un-escaping escaped characters. how tackle issue?

this how have be:

set @var_query = select * sample_table col=?'; set @data = text_data; prepare stmt @var_query; execute stmt using @data; deallocate prepare stmt; 

while

escape string gets un-escaped in mysql concat function

is correct , proper behavior.