Hi all,

I have been trying to merge my data using key variables but error I keep getting is : " key variable do not uniquely identify observations in the using data"

The is my first data
----------------------- copy starting from the next line -----------------------
Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input str10 id float(date days) byte measurement float date1 int(sugar ice smoke sugar2 ice1 smoke1 ice2 cie3) float(number date4)
"44" 21213 130 12 21327 120 70   .  . . . . . 18 21369
"44" 21213 130  8 21290 112 64   .  . . . . . 18 21369
"30" 21213 130  2 21329 140 85   .  . . . . . 19 21369
"30" 21213 130 10 21306 120 70   .  . . . . . 18 21369
"30" 21213 130  4 21251 126 62   .  . . . . . 18 21369
"30" 21213 130  6 21264 110 60   .  . . . . . 18 21369
"30" 21213 144  5 21255 133 62   .  . . . . . 18 21369
""       . 144  3 21241 108 70   .  . . . . . 18 21369
"30" 21213 130 11 21318 130 70 130 60 . . . . 18 21369
"30" 21213 144  2 21235 124 76   .  . . . . . 18 21369
"30" 21213 130  1 21227 118 62   .  . . . . . 18 21369
"30" 21213 130  7 21269 120 58   .  . . . . . 18 21369
"44" 21213 130  1 21284 105 55   .  . . . . . 19 21369
"44" 21213 130  9 21297 124 60   .  . . . . . 18 21369
"44" 21213 130  1 21192 112 64   .  . . . . . 17 21369
end
format %tdDD/NN/CCYY date
format %td date1
format %tdDD/NN/CCYY date4

This is the second data:

----------------------- copy starting from the next line -----------------------
Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input str10 id int(read1 read2) float(time self days value exp1 obse1)
"419" 110 58             . 1 1 . . .
"3"   120 46 1.8054964e+12 1 4 . . .
"39"   81 44 1.8510804e+12 1 3 . . .
"39"   84 50  1.724345e+12 1 3 . . .
"39"   84 50 1.8505718e+12 1 3 . . .
"39"  109 45             . 1 3 . . .
"39"  143 50  1.850501e+12 1 3 . . .
"39"  153 50 1.8138373e+12 1 4 . . .
"373" 120 48 1.8326545e+12 1 5 . . .
"373" 123 59 1.8765867e+12 1 5 . . .
"373" 120 58   1.85383e+12 1 5 . . .
"87"  120 50 1.8529647e+12 1 5 . . .
"87"  100 50 1.8534015e+12 1 5 . . .
"87"   89 50 1.7746176e+12 1 5 . . .
"87"    9 50 1.8555128e+12 1 5 . . .
"26"  121 48 1.7681596e+12 1 5 . . .
end
format %tcDD/NN/CCYY_HH:MM time
format %tdDD/NN/CCYY value
------------------ copy up to and including the previous line ------------------

Listed 16 out of 16 observations

Any help would be greatly appreaciated