use "D:\……\data.dta" , clear
preserve
qui forvalues i= 1/55391 {
keep if _n=`i'
save "D:\……\newdata_`i'.dta" , replace
}
restore
use "D:\……\main_data.dta"
qui forvalues `j' =1/55391{
merge 1:m 变量1 变量2 using "D:\……\newdata_`j'.dta"
keep if _merge==3
save "D:\……\newdataafter_`j'.dta" , replace
}
use "D:\……\newdataafter_1.dta" , clear
forvalues i= 2/55391{
append using "D:\……\newdataafter_"`i'".dta"
}
save "D:\……\alldata.dta", replace