Hi Dan, Your statement seems to insert a NULL into max_value
sqlite> delete from source_table; sqlite> delete from max_value; sqlite> INSERT INTO max_value SELECT max(value) FROM source_table WHERE EXISTS (SELECT 1 FROM source_table); sqlite> select * from max_value; max_value sqlite> Erik Nelson's solution works - sqlite> delete from max_value; sqlite> delete from source_table; sqlite> insert into max_value select value from source_table order by value desc limit 1; sqlite> select * from max_value; sqlite> insert into source_table select 6; sqlite> insert into max_value select value from source_table order by value desc limit 1; sqlite> select * from max_value; max_value 6 sqlite> According to https://www.sqlite.org/lang_aggfunc.html - max(X) The max() aggregate function returns the maximum value of all values in the group. The maximum value is the value that would be returned last in an ORDER BY on the same column. Aggregate max() returns NULL if and only if there are no non-NULL values in the group. despite that - sqlite> delete from source_table; sqlite> select * from source_table order by value; sqlite> select max(value) from source_table; max(value) sqlite> The behavior of SELECT max(X) from an empty table appears to contradict the documentation, or have I misunderstood something? On 10 January 2018 at 19:38, Dan Kennedy <danielk1...@gmail.com> wrote: > On 01/10/2018 11:48 PM, Shane Dev wrote: > >> Hello, >> >> sqlite> create table source_table(value); >> sqlite> create table max_value(max_value); >> sqlite> insert into max_value select max(value) from source_table; >> sqlite> select * from table_max_value; >> max_value >> >> sqlite> >> >> >> How can the maximum value of column source_table.value be inserted into >> max_value only if there are records in source_table? (If source_table is >> empty, nothing should be inserted into max_value, not even a NULL) >> > > You could add a WHERE clause to your SELECT. > > INSERT INTO max_value SELECT max(value) FROM src WHERE EXISTS (SELECT 1 > FROM src); > > Or similar. > > _______________________________________________ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
