As well as showing the whole database, PHP can be used to select individual records, or records which match certain criteria. To do this you must use a variation of the SELECT query. To display the whole table use the query:
SELECT * FROM tablename
If we just want to select records which have value=1 in the field1-name row we would use the following query:
SELECT * FROM tablename WHERE field1-name='1'
In the same way you could select records based on any field in the database. You can also search in more fields by adding more:
field='value'
sections into the query.