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| From | Eric Booth <eric.a.booth@gmail.com> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: Merge Files one to many |
| Date | Sat, 31 Mar 2012 19:31:12 -0500 |
<> Since there is one principal observation per school & many teachers per school, you want a many-to-one merge with the teacher dataset in memory (assuming you've got Stata 12 since you didn't state otherwise -- you want to use the m:1 merge type). That is, if you use the teacher dataset (the first dataset) as the master dataset (in memory) and merge in the principal dataset (the second dataset) as the 'using' dataset, then you'd run something like: **** use "teacher.dta", clear merge m:1 schoolid using "principal.dta" //include any options here about updating, replacing, or matching values sa "combined.dta", replace *check your merge report or run -tabulate _merge- **** - Eric __ Eric A. Booth Public Policy Research Institute Texas A&M University ebooth@ppri.tamu.edu +979.845.6754 On Mar 31, 2012, at 7:00 PM, <theodroe@bellsouth.net> wrote: > Have two data sets with common variable. The teacher data set has several > teachers per school. The school variable is a nominal variable that is > unique to each school. So if there are 20 teachers in a school the school > variable is repeated 20 times. The principal data file has one principal per > school and I want to merge/match on school. There is one principal to each > school and this file uses the same school variable to identify the school > the principal is in. What I need to do is to match the principal data to > every teacher in that school. > > So the file would look like: > > > School teacher_var1 teacher_var2 principal_var1 > 123 23 45 56 > 123 25 44 56 > 123 21 43 56 > 123 56 55 56 > 331 21 22 51 > 331 21 29 51 > 331 26 21 51 > > Help please > > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/