create table named t3 (id, value). id is integer. value is text

sqlite> create table if not exists t3( id int , value varchar, primary key(id));

adding two “rows”

sqlite> insert into t3 (id, value) values (1, 'a');
sqlite> insert into t3 (id, value) values (2, 'b');

display results

sqlite> select *  from t3;
1|a
2|b

update id=1 if exists, insert otherwise (id=1 exists)

sqlite> insert or replace into t3 (id,value) values (1,‘c’ ); sqlite> select *  from t3; 2|b 1|c

update id=1 if exists, insert otherwise (id=1 doesn’t exist)

sqlite> insert or replace into t3 (id,value) values (3,‘e’ ); sqlite> select *  from t3; 2|b 1|c 3|e

update id=1 if exists, insert otherwise (id=1 doesn’t exist)

sqlite> insert or replace into t3 (id,value) values (3,‘f’ ); sqlite> select *  from t3; 2|b 1|c 3|f