>is there a sql command to append records from table A into table B?

Unfortunately VFP SQL is not as rich as SQL server's. First you would do a select into a cursor then an append from. When using append from be carefull to use dbf('cursorname').ie:

select ... from tableA into cursor myCursor nofilter
select TableB
append from dbf('myCursor')

BUT actually not using an SQL is a more direct way. ie :

select TableB
append from TableA for < Your expression here - SQL where part >

Cetin