Re: [sqlite] Count error?
Jim Morris, on Friday, November 1, 2019 12:07 PM, wrote... > > Using a sub-select should work > > select > > (select count(n) from t0) as "t0_count", > > (select count(n) from t1) as "t1_count", > > (select count(n) from t2) as "t2_count" > > ; Thanks. Works. josé > On 11/1/2019 9:07 AM, Jose Isaias Cabrera wrote: > > Jose Isaias Cabrera, on Friday, November 1, 2019 11:51 AM, wrote... > >> > >> Richard Hipp, on Friday, November 1, 2019 11:41 AM, wrote... > >>> On 11/1/19, Jose Isaias Cabrera, on > sqlite> select count(a.n),count(b.n),count(c.n) FROM t0 AS a LEFT JOIN > t1 AS > b LEFT JOIN t2 AS c; > 3375|3375|3375 > > Huh? I expected the result: > > 15|15|15 > >>> You did a three-way join on tables with 15 rows each. 15x15x15 is 3375. > >>> > >>> A LEFT JOIN without an ON clause is just a JOIN. Or, to view it > >>> another way, it is the same as having "ON true" on each LEFT JOIN. > >>> LEFT JOIN only differs from JOIN when the ON clause evaluates to false > >>> or NULL, in which case the right table of the LEFT JOIN pretends to be > >>> a table of a single row of all NULL values. > >> Thanks, Dr. Hipp. Now I understand why the real query hung, and didn't > >> produce a > >> response. Sorry for the lack of knowledge. :-) Anyone, out there, how do > >> I get > >> the record count of three tables in one call? Thanks. > > So, I got it to work in 3 rows, > > > > select count(n) from t0 UNION ALL Select count(n) FROM t1 UNION ALL SELECT > > count(n) FROM t2; > > 15 > > 15 > > 15 > > > > But, is there a way to get it to work on one row? Sorry for the newbie > > post. Thanks. > > > > josé ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Count error?
Using a sub-select should work select (select count(n) from t0) as "t0_count", (select count(n) from t1) as "t1_count", (select count(n) from t2) as "t2_count" ; On 11/1/2019 9:07 AM, Jose Isaias Cabrera wrote: > Jose Isaias Cabrera, on Friday, November 1, 2019 11:51 AM, wrote... >> >> Richard Hipp, on Friday, November 1, 2019 11:41 AM, wrote... >>> On 11/1/19, Jose Isaias Cabrera, on sqlite> select count(a.n),count(b.n),count(c.n) FROM t0 AS a LEFT JOIN t1 AS b LEFT JOIN t2 AS c; 3375|3375|3375 Huh? I expected the result: 15|15|15 >>> You did a three-way join on tables with 15 rows each. 15x15x15 is 3375. >>> >>> A LEFT JOIN without an ON clause is just a JOIN. Or, to view it >>> another way, it is the same as having "ON true" on each LEFT JOIN. >>> LEFT JOIN only differs from JOIN when the ON clause evaluates to false >>> or NULL, in which case the right table of the LEFT JOIN pretends to be >>> a table of a single row of all NULL values. >> Thanks, Dr. Hipp. Now I understand why the real query hung, and didn't >> produce a >> response. Sorry for the lack of knowledge. :-) Anyone, out there, how do I >> get >> the record count of three tables in one call? Thanks. > So, I got it to work in 3 rows, > > select count(n) from t0 UNION ALL Select count(n) FROM t1 UNION ALL SELECT > count(n) FROM t2; > 15 > 15 > 15 > > But, is there a way to get it to work on one row? Sorry for the newbie post. > Thanks. > > josé > ___ > 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
Re: [sqlite] Count error?
Jose Isaias Cabrera, on Friday, November 1, 2019 11:51 AM, wrote... > > > Richard Hipp, on Friday, November 1, 2019 11:41 AM, wrote... > > > > On 11/1/19, Jose Isaias Cabrera, on > > > sqlite> select count(a.n),count(b.n),count(c.n) FROM t0 AS a LEFT JOIN t1 > > > AS > > > b LEFT JOIN t2 AS c; > > > 3375|3375|3375 > > > > > > Huh? I expected the result: > > > > > > 15|15|15 > > > > You did a three-way join on tables with 15 rows each. 15x15x15 is 3375. > > > > A LEFT JOIN without an ON clause is just a JOIN. Or, to view it > > another way, it is the same as having "ON true" on each LEFT JOIN. > > LEFT JOIN only differs from JOIN when the ON clause evaluates to false > > or NULL, in which case the right table of the LEFT JOIN pretends to be > > a table of a single row of all NULL values. > > Thanks, Dr. Hipp. Now I understand why the real query hung, and didn't > produce a > response. Sorry for the lack of knowledge. :-) Anyone, out there, how do I > get > the record count of three tables in one call? Thanks. So, I got it to work in 3 rows, select count(n) from t0 UNION ALL Select count(n) FROM t1 UNION ALL SELECT count(n) FROM t2; 15 15 15 But, is there a way to get it to work on one row? Sorry for the newbie post. Thanks. josé ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Count error?
Richard Hipp, on Friday, November 1, 2019 11:41 AM, wrote... > > On 11/1/19, Jose Isaias Cabrera, on > > sqlite> select count(a.n),count(b.n),count(c.n) FROM t0 AS a LEFT JOIN t1 AS > > b LEFT JOIN t2 AS c; > > 3375|3375|3375 > > > > Huh? I expected the result: > > > > 15|15|15 > > You did a three-way join on tables with 15 rows each. 15x15x15 is 3375. > > A LEFT JOIN without an ON clause is just a JOIN. Or, to view it > another way, it is the same as having "ON true" on each LEFT JOIN. > LEFT JOIN only differs from JOIN when the ON clause evaluates to false > or NULL, in which case the right table of the LEFT JOIN pretends to be > a table of a single row of all NULL values. Thanks, Dr. Hipp. Now I understand why the real query hung, and didn't produce a response. Sorry for the lack of knowledge. :-) Anyone, out there, how do I get the record count of three tables in one call? Thanks. josé ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Count error?
On 11/1/19, Jose Isaias Cabrera wrote: > sqlite> select count(a.n),count(b.n),count(c.n) FROM t0 AS a LEFT JOIN t1 AS > b LEFT JOIN t2 AS c; > 3375|3375|3375 > > Huh? I expected the result: > > 15|15|15 You did a three-way join on tables with 15 rows each. 15x15x15 is 3375. A LEFT JOIN without an ON clause is just a JOIN. Or, to view it another way, it is the same as having "ON true" on each LEFT JOIN. LEFT JOIN only differs from JOIN when the ON clause evaluates to false or NULL, in which case the right table of the LEFT JOIN pretends to be a table of a single row of all NULL values. -- D. Richard Hipp d...@sqlite.org ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
