help isid dialog: isid
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Title
[D] isid -- Check for unique identifiers
Syntax
isid varlist [using filename] [, sort missok]
Menu
Data > Data utilities > Check for unique identifiers
Description
isid checks whether the specified variables uniquely identify the
observations.
Options
sort indicates that the dataset be sorted by varlist.
missok indicates that missing values are permitted in varlist.
Examples
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Setup
. sysuse auto
Check whether mpg uniquely identifies observations
. isid mpg
Check whether make uniquely identifies observations
. isid make
Setup
. replace make = "" in 1
Check whether make uniquely identifies observations
. isid make
Same as above command, but permit missing values in make
. isid make, missok
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Setup
. webuse grunfeld, clear
Check whether panel and time variables uniquely identify observations
. isid company year
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Also see
Manual: [D] isid
Help: [D] describe, [D] duplicates, [D] lookfor; [D] codebook, [D]
inspect
