Query - Refining Queries
You can refine queries by combining words with Boolean operators. To do this:
Click the "Add Search Line" button located above the query form. A new search line will appear. Add enough search lines so you can type one word per line. A notable exception: Do not separate species names, type the full name in one line.
- Use AND in front of each word that must appear in the results.
- Use AND NOT in front of the word you want to exclude from the results.
- To find data that includes at least one of your words use OR.
Select "Nucleotide (nuccore)" which is a data source that can be found within Nucleotide Sequences and try the below examples for practice:
- Click Add Search Line three times, then enter:
Definition = heat
AND Definition = shock
AND Definition = factor
AND Species = gallus gallus
...this will return records for "heat shock factor" in Gallus Gallus.
- Return to the Query page and change the Boolean operator in the Species line to AND NOT and records that contain the species Gallus Gallus will be omitted from your results.
- Using two search lines, enter:
Gene = cdh4
OR Gene = C4
...this will return records that mention one or the other gene name, but not necessarily both.
Other important information
- A query can contain up to 10 search lines.
- A query can contain one or several Boolean operators.
- A query can contain a mix of Boolean operators (like AND and AND NOT).
- A query can contain multiple occurrences of the same Boolean operator.
- Boolean operators do not work with the All Text field.
- A query can contain multiple occurrences of the same Search Field.