Your search strategy should be clearly documented so that it can be recorded correctly in the systematic review and reproduced for verification.
For each of the databases searched you need to record:
It is a good idea to save your search strategies in the databases you use so you can refer back to them later. Databases such as Medline, Embase, Scopus, ScienceDirect, Web of Science, PsycINFO and Cochrane have this feature.
Use a template spreadsheet to record these details - like this Search audit template [Excel spreadsheet] from Cochrane's EPOC resources for Authors