SELECT @start_value; @start_value
NULL
'#---------------------FN_DYNVARS_004_01-------------------------#' SET @@global.general_log_file = DEFAULT; SELECT RIGHT(@@global.general_log_file,10) AS log_file; log_file
mysqld.log
'#--------------------FN_DYNVARS_004_02------------------------#' SET @@global.general_log_file = mytest.log;
SET @@global.general_log_file = 12; ERROR 42000: Incorrect argument type to variable 'general_log_file'
'#----------------------FN_DYNVARS_004_03------------------------#' SELECT @@global.general_log_file = VARIABLE_VALUE FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE VARIABLE_NAME='general_log_file'; @@global.general_log_file = VARIABLE_VALUE 1
SET @@global.general_log_file= 'start_value';