12/27/2023 0 Comments Sas merge by![]() * Sex indicator flags first and last sex records before it changes * By variables - first level is sex, second level is name * QC using proc means for numeric vars and proc freq (obs=20) for char vars * Save to final variables and output record If start_date hdada_stoptdt then hdada_stoptdt = stop_date * Update holding values if larger or smaller values * Create by patient processing and summarize to one record per patient įormat dada_startdt dada_stopdt yymmdd10. values with multiple BY variables ( SAS Syntax, SAS Blog) REGION * Instead of PROC SQL, DATA step is a better option to standardize variable length as a pre step before merging common structure datasets ģ. (Generally horizontal as 1:1 or 1:M, Use PROC APPEND for vertical joins) Name Merging Datasets/Lookup Techniques (See also SAS 9.2) If a not b then output anotb if a and b then output aandb if b not a then output bnota if b then output allb run Ģ. IF FIRST.SEX WHERE SEX = 'M' Īppend/Set/Contatenate Interleave Merge w/, w/o Byĭata allab merge a (in=a) b (in=b) by id if a then a=1 if b then b=1 run ĭata allab alla anotb aandb bnota allb merge a (in=a) b (in=b) by id if a or b then output allab if a then output alla IF/WHERE condition to subset dataset, ex. RETAIN COUNT2 COUNT2=SUM(COUNT2 + 1) or COUNT2 + 1 Calculations based on differences between one or more variables across rows Calculations based on differences between one or more variables (MAX(), RETAIN)ĥ. values with multiple BY variables ( SAS Syntax)Ĥ. Merging Datasets / Lookup Techniques (1:1, 1:M)ģ. SET options ( SAS Syntax), Dataset options ( SAS Syntax)Ģ. ĭata Management Techniques (DATA Step Programming)ġ. See also on-line reference one and two.Īssigning Special Character Values to Character Variables See also DATA Step SAS examples, Common FAQ and Training Videos on selected SAS topics. See also Access to External files, SAS Certification, SAS Functions/Informats and Formats, SAS Dates and Proc SQL. For customized reports, there is a section on DATA _NULL_ reporting.īelow is a collection of SAS ® papers categorized by General, Data Management, Arrays, and Merging Datasets. For example in the pharmaceutical industry, the DATA step is used to post-process RTF files. What's In a Variable Name? ( Data Step/Merge Blog )Īlong with converting text files to SAS ® datasets, the DATA step has the power to create and manage variables. ![]() Lost without SAS Indexes? ( SAS Options Blog)įive Habits of Highly Effective SAS Programmers ( Compare and Conquer SAS Programming Blog) ![]() Reading and Writing to Excel files ( Excel Blog) Which comes first PUT() or the INPUT()? (SAS Functions Blog Summary Sheet) IF Statements: Knowing the Difference in How and When to Apply Next, we provide an example to do a left join with the MERGE statement.Best of Both Worlds: Data Step and Proc SQL Joins ( Proc SQL Blog) Namely, if you want to perform a left join on two or more large tables, the MERGE statement is faster than the SQL procedure. For example, you can’t merge two tables with the column names first_name and firstname.Īll these extra requirements come with a benefit. You can do this with the PROC SORT procedure.Īdditionally (and also in contrast to the PROC SQL procedure), the column names to find matching records must be identical. In contrast to the PROC SQL procedure, the MERGE statement requires that the input tables must be ordered. For example, that you want to keep all records from the left table plus the matching records from the right table. The IF statement specifies the type of join. After the MERGE statement follows a BY statement to specify the columns you want to match.įinally, to create a (left) join, you need an IF statement. In a SAS Data Step, you start a join with the MERGE statement followed by the names of the tables you want to combine. METHOD 2: Left Join Table with a SAS Data StepĪlternatively, you can use a SAS Data Step to join data from two or more data sets.
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