Either SQLite doesn't support multiple statements in one go or the FPC SQLDB just passes on the first statements.
A solution: use a parameterized query (e.g. Update MyTable set MyField=:MyFieldPar;
), then run the update statements in a loop (e.g. something like, untested, Query.ParamByName('MyFieldPar').AsInteger:=2;
Query.ExecSQL;
Query.ParamByName('MyFieldPar').AsInteger:=1;
Query.ExecSQL;
Of course, you don't especially need to use parameterized queries when inserting integers...