Data Management Reference Manual

This manual includes features that are part of StataNow™.

Publisher: Stata Press
Copyright: 2025
ISBN-13: 978-1-59718-422-9
Pages: 995

Suggested citation:
StataCorp. 2025. Stata 19 Data Management Reference Manual. College Station, TX: Stata Press.


Table of contents
Intro Introduction to data management reference manual
Data management Introduction to data management commands


append Append datasets
assert Verify truth of claim
assertnested Verify variables nested


bcal Business calendar file manipulation
by Repeat Stata command on subsets of the data


cd Change directory
cf Compare two datasets
changeeol Convert end-of-line characters of text file
checksum Calculate checksum of file
clear Clear memory
clonevar Clone existing variable
codebook Describe data contents
collapse Make dataset of summary statistics
compare Compare two variables
compress Compress data in memory
contract Make dataset of frequencies and percentages
copy Copy file from disk or URL
corr2data Create dataset with specified correlation structure
count Count observations satisfying specified conditions
cross Form every pairwise combination of two datasets


Data types Quick reference for data types
datasignature Determine whether data have changed
Datetime Date and time values and variables
Datetime business calendars Business calendars
Datetime business calendars creation Business calendars creation
Datetime conversion Converting strings to Stata dates
Datetime display formats Display formats for dates and times
Datetime durations Obtaining and working with durations
Datetime relative dates Obtaining dates and date information from other dates
Datetime values from other software Date and time conversion from other software
describe Describe data in memory or in file
destring Convert string variables to numeric variables and vice versa
dir Display filenames
drawnorm Draw sample from multivariate normal distribution
drop Drop variables or observations
ds Compactly list variables with specified properties
duplicates Report, tag, or drop duplicate observations
dyngen Dynamically generate new values of variables


edit Browse or edit data with Data Editor
egen Extensions to generate
encode Encode string into numeric and vice versa
erase Erase a disk file
expand Duplicate observations
expandcl Duplicate clustered observations
export Overview of exporting data from Stata


filefilter Convert ASCII or binary patterns in a file
fillin Rectangularize dataset
format Set variables' output format
fralias Alias variables from linked frames
frames intro Introduction to frames
frames Data frames
frame change Change identity of current (working) frame
frame copy Make a copy of a frame
frame create Create a new frame
frame drop Drop frame from memory
frame prefix The frame prefix command
frame put Copy selected variables or observations to a new frame
frame putlabel Copy value labels to other frames
frame pwf Display name of current (working) frame
frame rename Rename existing frame
frames dir Display names of all frames in memory
frames modify Modify a set of frames on disk
frames reset Drop all frames from memory
frget Copy variables from linked frame
frlink Link frames
frunalias Change storage type of alias variables


generate Create or change contents of variable
gsort Ascending and descending sort


hexdump Display hexadecimal report on file


icd Introduction to ICD commands
icd9 ICD-9-CM diagnosis codes
icd9p ICD-9-CM procedure codes
icd10 ICD-10 diagnosis codes
icd10cm ICD-10-CM diagnosis codes
icd10pcs ICD-10-PCS procedure codes
import Overview of importing data into Stata
import dbase Import and export dBase files
import delimited Import and export delimited text data
import excel Import and export Excel files
import fred Import data from Federal Reserve Economic Data
import haver Import data from Haver Analytics databases
import haverdirect Import data from Haver Analytics Cloud servers
import parquet Import Parquet data StataNow
import sas Import SAS files
import sasxport5 Import and export data in SAS XPORT Version 5 format
import sasxport8 Import and export data in SAS XPORT Version 8 format
import spss Import SPSS files
infile (fixed format) Import text data in fixed format with a dictionary
infile (free format) Import unformatted text data
infix (fixed format) Import text data in fixed format
input Enter data from keyboard
insobs Add or insert observations
inspect Display simple summary of data's attributes
ipolate Linearly interpolate (extrapolate) values
isid Check for unique identifiers


jdbc Load, write, or view data from a database with a Java API
joinby Form all pairwise combinations within groups


label Manipulate labels
label language Labels for variables and values in multiple languages
labelbook Label utilities
list List values of variables
lookfor Search for string in variable names and labels


memory Memory management
merge Merge datasets
Missing values Quick reference for missing values
mkdir Create directory
mvencode Change missing values to numeric values and vice versa


notes Place notes in data


obs Increase the number of observations in a dataset
odbc Load, write, or view data from ODBC sources
order Reorder variables in dataset
outfile Export dataset in text format


pctile Create variable containing percentiles
putmata Put Stata variables into Mata and vice versa


range Generate numerical range
recast Change storage type of variable
recode Recode categorical variables
rename Rename variable
rename group Rename groups of variables
reshape Convert data from wide to long form and vice versa
rmdir Remove directory


sample Draw random sample
save Save Stata dataset
separate Create separate variables
shell Temporarily invoke operating system
snapshot Save and restore data snapshots
sort Sort data
split Split string variables into parts
splitsample Split data into random samples
stack Stack data
statsby Collect statistics for a command across a by list
sysuse Use shipped dataset


type Display contents of a file


unicode Unicode utilities
unicode collator Language-specific Unicode collators
unicode convertfile Low-level file conversion between encodings
unicode encoding Unicode encoding utilities
unicode locale Unicode locale utilities
unicode translate Translate files to Unicode
use Load Stata dataset


varmanage Manage variable labels, formats, and other properties
vl Manage variable lists
vl create Create and modify user-defined variable lists
vl drop Drop variable lists or variables from variable lists
vl list List contents of variable lists
vl rebuild Rebuild variable lists
vl set Set system-defined variable lists


webuse Use dataset from Stata website


xpose Interchange observations and variables


zipfile Compress and uncompress files and directories in zip archive format


Glossary


Combined author index
Combined subject index