Example: Three Sample Sets Using SAMPLEID as a Select List Expression
The following SELECT statement provides three mutually exclusive sample sets (60 percent for sample category x, 25 percent for sample category y, and 15 percent for sample category z) from a customer table.
The results are returned in a table with three columns: cust_name, cust_addr, and SAMPLEID.
The integer in the SAMPLEID column identifies whether the row belongs to the 0.6 sample, the 0.25 sample, or the 0.15 sample.
The samples are identified as 1 through 3, in left-to-right order from the SAMPLE clause, so 0.6 is identified by 1, 0.25 by 2, and 0.15 by 3.
SELECT cust_name, cust_addr, SAMPLEID FROM customer_table SAMPLE 0.6, 0.25, 0.15;
A partial results table might look something like the following:
| cust_name | cust_addr | SAMPLEID |
|---|---|---|
| Jones Pharmaceuticals | 4235 Lawler Road Memphis, TN USA |
1 |
| Fong Furniture | 310 East Highway 5 Hong Kong |
2 |
| Subramaniam Spice Exports | 455 1/2 Gandhi Lane Hyderabad India |
3 |
| Forrester Property Management | 1 West Broadway Syracuse, New York USA |
1 |
| Otomo Consulting | 33 Korakuen Hall Tokyo Japan |
1 |
| Adler Music Publishing, Ltd. | 5 East 245th Street Nashville, TN USA |
|
| O’Brien Metals | 83 Heatherington The Whithers Cobblestone-on-Treads United Kingdom |
1 |
| Irama Rice Importers | 8562 Rhoma Lane Jakarta Indonesia |
2 |
| Abdelwahab Fine Egyptian Rugs | 1723 Kulthum Avenue Cairo Egypt |
1 |
| Bachar Ouds | 18 Rashied Diagonal Baghdad Iraq |
1 |
Example: Using SAMPLEID With PERIOD Value Expressions
The following example shows how you can specify a PERIOD value expression with a SAMPLEID expression, where period_of_stay is the PERIOD value expression.
SELECT emp_no, period_of_stay, SAMPLEID FROM employee SAMPLE 0.5,0.5;