How do you physically and virtually join multiple tables in JMP?
Feb 7, 2019 12:48 PM
| Last Modified: Aug 19, 2020 12:04 PM
JMP lets you physically join data from up to 60 tables. Or, to save memory and space, you can link (virtually join) a main JMP data table to one or more updatable auxiliary data tables without physically joining the tables.
Systems Engineer Olivia Lippincott @olippincott demonstrates how.
Physically Joining Tables
After importing data into JMP, you can join any two tables based on a common column. JMP lets you choose the columns interactively. The columns do not need to have the same name. And, you can interactively filter column values to import/join only selected column values into the JMP table.
In the first part of this demo, Olivia imports data from different sources (Internet, database, Excel) and then joins them, showing how you can selectively filter and import only selected values (in this case, females) for a particular column.
JMP lets you interactively filter and select specific values to import into the joined table..
Results of final physical join into one JMP table.
Virtually Joining Tables
Virtually joining tables saves memory, because the same data are not replicated in every table that references them. Linked data can be independently updated in the main JMP table without being updated in the auxiliary (referencing) table. As when physically joining tables, tables are joined by common columns. The columns must have unique IDs. If they don't, JMP will alter you so that you can correct the problem.
In the second part of this demo, Olivia creates a Link ID and a Link Reference. The Link ID column in the auxiliary (referencing) table will match the Link Reference column in the main JMP table. She performs an analysis in the virtually joined data. The next time she opens the main table, if the auxiliary data table has been updated, her analysis will use the new data.
Creating Link ID in auxiliary (referenced) table column while setting up virtual join.
Creating Link Reference in main table column while setting up virtual join.
JMP alerts you if you choose a Link ID column that does not have unique values.