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Diffstat (limited to 'mysql-test/main/rownum.result')
| -rw-r--r-- | mysql-test/main/rownum.result | 986 |
1 files changed, 986 insertions, 0 deletions
diff --git a/mysql-test/main/rownum.result b/mysql-test/main/rownum.result new file mode 100644 index 00000000000..3ad51c93260 --- /dev/null +++ b/mysql-test/main/rownum.result @@ -0,0 +1,986 @@ +CREATE OR REPLACE TABLE t1(a int, b int) engine=aria; +CREATE OR REPLACE TABLE t2(a int, b int) engine=aria; +insert into t1 values (1,10),(2,20),(3,30); +insert into t2 values (2,21),(3,31),(4,41); +# +# Simple selects +# +select a,b,rownum() from t1; +a b rownum() +1 10 1 +2 20 2 +3 30 3 +select a,b,rownum() from t1 where rownum() < 2; +a b rownum() +1 10 1 +select a,b from t1 where rownum() <= 2; +a b +1 10 +2 20 +select a,b from t1 where rownum() > 2; +a b +# +# Subqueries +# +select t1.a,rownum(),t3.a,t3.t2_rownum from t1, (select t2.a,rownum() as t2_rownum from t2 where rownum() <=2) t3; +a rownum() a t2_rownum +1 1 2 1 +1 2 3 2 +2 3 2 1 +2 4 3 2 +3 5 2 1 +3 6 3 2 +select t1.a, (select t2.b from t2 where t1.a=t2.a and rownum() <= 1) 'b' from t1; +a b +1 NULL +2 21 +3 31 +select t1.a, t3.a from t1, (select * from t2 where rownum() <= 2) t3; +a a +1 2 +1 3 +2 2 +2 3 +3 2 +3 3 +select * from (select tt.*,rownum() as id from (select * from t1) tt) t3 where id>2; +a b id +3 30 3 +# +# Joins +# +select t1.a,t1.b,t2.a,t2.b,rownum() from t1,t2 where rownum() <= 4; +a b a b rownum() +1 10 2 21 1 +2 20 2 21 2 +3 30 2 21 3 +1 10 3 31 4 +select *,rownum() from t1,t2 where t1.a=t2.a and rownum()<=2; +a b a b rownum() +2 20 2 21 1 +3 30 3 31 2 +select * from t1 left join t2 on (t2.a=t1.a and rownum()=0); +a b a b +1 10 NULL NULL +2 20 NULL NULL +3 30 NULL NULL +select * from t1 left join t2 on (t2.a=t1.a and rownum()>1); +a b a b +1 10 NULL NULL +2 20 NULL NULL +3 30 NULL NULL +select * from t1 left join t2 on (t2.a=t1.a and rownum()<1); +a b a b +1 10 NULL NULL +2 20 NULL NULL +3 30 NULL NULL +select * from t1 left join t2 on (t2.a=t1.a and rownum()=1); +a b a b +2 20 2 21 +1 10 NULL NULL +3 30 NULL NULL +select * from t1 left join t2 on (t2.a=t1.a and rownum()>=1); +a b a b +2 20 2 21 +3 30 3 31 +1 10 NULL NULL +# +# Union +# +select * from t1 where rownum() <=2 union select * from t2 where rownum()<= 1; +a b +1 10 +2 20 +2 21 +# +# Order by +# +select * from t1 where rownum() <= 2 order by a desc; +a b +2 20 +1 10 +explain select * from t1 where rownum() <= 2 order by a desc; +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where; Using filesort +select t1.a,t1.b,rownum() from t1 where rownum() <= 2 order by a desc; +a b rownum() +2 20 2 +1 10 1 +explain select t1.a,t1.b,rownum() from t1 where rownum() <= 2 order by a desc; +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where; Using temporary; Using filesort +select *,rownum() from t1,t2; +a b a b rownum() +1 10 2 21 1 +2 20 2 21 2 +3 30 2 21 3 +1 10 3 31 4 +2 20 3 31 5 +3 30 3 31 6 +1 10 4 41 7 +2 20 4 41 8 +3 30 4 41 9 +select *,rownum() from t1,t2 order by t2.a desc, t1.a desc; +a b a b rownum() +3 30 4 41 9 +2 20 4 41 8 +1 10 4 41 7 +3 30 3 31 6 +2 20 3 31 5 +1 10 3 31 4 +3 30 2 21 3 +2 20 2 21 2 +1 10 2 21 1 +select * from (select * from t1 order by a desc) as t where rownum() <= 2; +a b +3 30 +2 20 +select * from t1,t2 where t1.a=t2.a and rownum()<=2 order by t1.a,t2.a; +a b a b +2 20 2 21 +3 30 3 31 +# +# Having +# +select t1.a, sum(t1.b), rownum() as 'r' from t1 group by t1.a having r <= 2; +a sum(t1.b) r +1 10 1 +2 20 2 +select * from t1 having rownum() <= 2; +a b +1 10 +2 20 +select t1.a, sum(t1.b), rownum() from t1 group by t1.a; +a sum(t1.b) rownum() +1 10 1 +2 20 2 +3 30 3 +select t1.a, sum(t1.b), rownum() as 'r' from t1 group by t1.a having r <= 2; +a sum(t1.b) r +1 10 1 +2 20 2 +select t1.a, sum(t1.b), rownum() as 'r' from t1 group by t1.a having rownum() <= 2; +a sum(t1.b) r +1 10 1 +2 20 2 +select t1.a, sum(t1.b), rownum() as 'r' from t1 group by t1.a having r <= 2 order by a desc; +a sum(t1.b) r +2 20 2 +1 10 1 +select t1.a, sum(t1.b), rownum() as 'r' from t1 group by t1.a having rownum() <= 2 order by a desc; +a sum(t1.b) r +2 20 2 +1 10 1 +# +# Sum functions +# +select max(rownum()),min(rownum()) from t1; +max(rownum()) min(rownum()) +3 1 +select sum(rownum()),avg(rownum()) from t1; +sum(rownum()) avg(rownum()) +6 2.0000 +# +# Group by +# +select t1.a,sum(t1.b) from t1 where rownum() < 2 group by t1.a; +a sum(t1.b) +1 10 +select t1.a,sum(t2.b) from t1 JOIN t2 ON (t1.a=t2.a) where rownum() <= 2 group by t1.a; +a sum(t2.b) +2 21 +3 31 +select * from (select t1.a,sum(t2.b) from t1 JOIN t2 ON (t1.a=t2.a) group by t1.a) as t where rownum() <= 1; +a sum(t2.b) +2 21 +select t1.a,sum(rownum()),count(*) from t1 where rownum() <= 2 group by t1.a; +a sum(rownum()) count(*) +1 1 1 +2 2 1 +select * from (select t1.a,sum(t1.b) from t1 group by t1.a) as t3 where rownum() < 2; +a sum(t1.b) +1 10 +create table t3 (a int) engine=myisam; +insert into t3 values (3),(5),(5),(3); +select a, max(rownum()) from t3 group by a; +a max(rownum()) +3 4 +5 3 +drop table t3; +CREATE TABLE t3 ( +a int(11) DEFAULT NULL, +b varchar(1024) DEFAULT NULL +); +insert into t3 select mod(seq*3,20)+1, repeat(char(33+mod(seq,90)),mod(seq,10)*100) from seq_1_to_23; +SELECT sq.a,length(sq.f) FROM (SELECT a, GROUP_CONCAT(b,b) AS f FROM t3 GROUP BY a ORDER BY a desc) as sq WHERE ROWNUM() <= 10; +a length(sq.f) +20 600 +19 1200 +18 1800 +17 400 +16 1000 +15 1600 +14 200 +13 800 +12 1400 +11 0 +drop table t3; +# +# Prepared statements +# +PREPARE stmt1 from "select a,b,rownum() from t1 where rownum() <= 2"; +execute stmt1; +a b rownum() +1 10 1 +2 20 2 +execute stmt1; +a b rownum() +1 10 1 +2 20 2 +deallocate prepare stmt1; +# +# Views +# +create view v1 as select t1.a,rownum() from t1; +select * from v1; +a rownum() +1 1 +2 2 +3 3 +select t1.a,v1.* from t1,v1 where t1.a=v1.a; +a a rownum() +1 1 1 +2 2 2 +3 3 3 +drop view v1; +CREATE TABLE t3 (a INT); +INSERT INTO t3 VALUES (1),(2),(3); +CREATE VIEW v1 AS SELECT a FROM t3 WHERE ROWNUM() <= 2; +SELECT * FROM v1; +a +1 +2 +drop view v1; +drop table t3; +# +# Reserved words +# +create table t4 (a int, rownum int); +insert into t4 (a,rownum) values (1,2); +select t4.a,t4.rownum from t4; +a rownum +1 2 +drop table t4; +# +# Test Oracle mode +# +set SQL_MODE=ORACLE; +select t1.a,rownum from t1 where rownum<=2; +a rownum +1 1 +2 2 +select t1.a,rownum() from t1 where rownum()<=2; +a rownum() +1 1 +2 2 +create table t4 (a int, rownum int); +ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'rownum int)' at line 1 +DECLARE +CURSOR c_cursor +IS select a,b,rownum from t1 where rownum <= 2; +v_a t1.a%TYPE; +v_b t1.b%TYPE; +v_rn t1.a%TYPE; +BEGIN +OPEN c_cursor; +FETCH c_cursor INTO v_a, v_b, v_rn; +WHILE c_cursor%FOUND LOOP +SELECT concat(v_a,'--',v_b,'--',v_rn); +FETCH c_cursor INTO v_a, v_b, v_rn; +END LOOP; +CLOSE c_cursor; +END;| +concat(v_a,'--',v_b,'--',v_rn) +1--10--1 +concat(v_a,'--',v_b,'--',v_rn) +2--20--2 +select a, rownum from t1 group by a, rownum having rownum < 3; +a rownum +1 1 +2 2 +select a, rownum as r from t1 group by a, rownum having r < 3; +a r +1 1 +2 2 +select a, rownum from t1 group by a, rownum having "rownum" < 3; +a rownum +1 1 +2 2 +select a, rownum from t1 group by a, rownum having rownum < 3 order by a desc; +a rownum +2 2 +1 1 +select a, rownum as r from t1 group by a, rownum having r < 3 order by a desc; +a r +2 2 +1 1 +select a, rownum from t1 group by a, rownum having "rownum" < 3 order by a desc; +a rownum +2 2 +1 1 +set SQL_MODE=DEFAULT; +# Cleanup +drop table t1,t2; +# +# INSERT +# +create table t1 (a int not null primary key, b int); +insert into t1 values (1,rownum()),(2,rownum()),(3,rownum()); +select * from t1; +a b +1 1 +2 2 +3 3 +drop table t1; +# +# INSERT DELAYED +# +create table t1 (a int not null primary key, b int); +insert delayed into t1 values (1,rownum()),(2,rownum()),(3,rownum()); +select * from t1; +a b +1 1 +2 2 +3 3 +drop table t1; +# +# INSERT IGNORED +# +create table t1 (a int not null primary key, b int); +insert ignore into t1 values (1,rownum()),(2,rownum()),(2,rownum()),(3,rownum()); +Warnings: +Warning 1062 Duplicate entry '2' for key 'PRIMARY' +select * from t1; +a b +1 1 +2 2 +3 4 +delete from t1; +insert ignore into t1 select * from (values (1,rownum()),(2,rownum()),(2,rownum()),(3,rownum())) t; +Warnings: +Warning 1062 Duplicate entry '2' for key 'PRIMARY' +select * from t1; +a b +1 1 +2 2 +3 4 +drop table t1; +# +# INSERT ... RETURNING +# +create or replace table t1 (a int); +insert into t1 values (1),(2) returning a, rownum(); +a rownum() +1 1 +2 2 +drop table t1; +# +# UPDATE +# +create table t1 (a int not null primary key, b int); +insert into t1 values (1,1),(2,2),(3,3); +update t1 set b=0; +update t1 set b=rownum()+1; +select * from t1; +a b +1 2 +2 3 +3 4 +update t1 set b=0; +update t1 set b=rownum() where a < 10 and rownum() < 2; +select * from t1; +a b +1 1 +2 0 +3 0 +drop table t1; +create table t1 (a int); +insert into t1 values (10),(20),(30); +update t1 set a = rownum(); +select * from t1; +a +1 +2 +3 +update t1 set a = rownum(); +select * from t1; +a +1 +2 +3 +drop table t1; +# +# DELETE +# +create table t1 (a int not null primary key, b int); +insert into t1 values (1,1),(2,0),(3,0); +delete from t1 where a < 10 and rownum() < 2; +select * from t1; +a b +2 0 +3 0 +drop table t1; +# +# MULTI-TABLE-DELETE +# +create table t1 (a int not null primary key); +insert into t1 values (1),(2),(3); +create table t2 (a int not null primary key); +insert into t2 values (1),(2),(3); +delete t1,t2 from t1,t2 where t1.a=t2.a and rownum() <= 2; +select * from t1; +a +3 +select * from t2; +a +3 +drop table t1,t2; +# +# MULTI-TABLE-UPDATE +CREATE TABLE t1 (ID INT); +CREATE TABLE t2 (ID INT, +s1 TEXT, s2 TEXT, s3 VARCHAR(10), s4 TEXT, s5 VARCHAR(10)); +INSERT INTO t1 VALUES (1),(2); +INSERT INTO t2 VALUES (1,'test', 'test', 'test', 'test', 'test'), +(2,'test', 'test', 'test', 'test', 'test'); +SELECT * FROM t1 LEFT JOIN t2 USING(ID); +ID s1 s2 s3 s4 s5 +1 test test test test test +2 test test test test test +UPDATE t1 LEFT JOIN t2 USING(ID) SET s1 = 'changed'; +select * from t2; +ID s1 s2 s3 s4 s5 +1 changed test test test test +2 changed test test test test +update t2 set s1=""; +UPDATE t1 LEFT JOIN t2 USING(ID) SET s1 = 'changed' where rownum() <=1; +select * from t2; +ID s1 s2 s3 s4 s5 +1 changed test test test test +2 test test test test +drop table t1,t2; +# +# LOAD DATA +# +create table t1 (a int, b int, c int); +load data infile '../../std_data/loaddata7.dat' into table t1 fields terminated by ',' lines terminated by "\r\n" (a,b) set c=rownum(); +select * from t1; +a b c +2 2 1 +3 3 2 +4 4 3 +5 5 4 +6 6 5 +drop table t1; +# +# LIMIT OPTIMIZATION +# +create table t1 (a int); +insert into t1 select seq from seq_1_to_100; +flush status; +select * from t1 where rownum() <= 3; +a +1 +2 +3 +show status like "Rows_read"; +Variable_name Value +Rows_read 3 +flush status; +select * from t1 where rownum() <= 4 and rownum() <= 3; +a +1 +2 +3 +show status like "Rows_read"; +Variable_name Value +Rows_read 3 +flush status; +select * from t1 where rownum() < 4 and a > 10; +a +11 +12 +13 +show status like "Rows_read"; +Variable_name Value +Rows_read 13 +flush status; +select * from t1 where 3 >= rownum(); +a +1 +2 +3 +show status like "Rows_read"; +Variable_name Value +Rows_read 3 +flush status; +select * from t1 where 4 > rownum() and a > 20; +a +21 +22 +23 +show status like "Rows_read"; +Variable_name Value +Rows_read 23 +flush status; +select * from t1 where rownum() = 1 and a > 10; +a +11 +show status like "Rows_read"; +Variable_name Value +Rows_read 11 +flush status; +select * from t1 where a > 30 && 1 = rownum(); +a +31 +show status like "Rows_read"; +Variable_name Value +Rows_read 31 +flush status; +# No limit optimization +select * from t1 where rownum() > 10; +a +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +select * from t1 where 10 < rownum(); +a +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +select * from t1 where rownum() >= 10; +a +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +select * from t1 where 10 < rownum(); +a +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +select * from t1 where 10 <= rownum(); +a +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +select * from t1 where 2 = rownum(); +a +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +select * from t1 where rownum() = 2; +a +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +select * from t1 where rownum() <= 0; +a +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +select *,rownum() from t1 where rownum() < 10 limit 4, 4; +a rownum() +5 5 +6 6 +7 7 +8 8 +show status like "Rows_read"; +Variable_name Value +Rows_read 8 +flush status; +select * from t1 where rownum() < 10 order by a; +a +1 +2 +3 +4 +5 +6 +7 +8 +9 +show status like "Rows_read"; +Variable_name Value +Rows_read 100 +flush status; +# rownum and limit +select * from t1 where rownum() < 4 limit 10; +a +1 +2 +3 +show status like "Rows_read"; +Variable_name Value +Rows_read 3 +flush status; +select * from t1 where rownum() < 10 limit 4; +a +1 +2 +3 +4 +show status like "Rows_read"; +Variable_name Value +Rows_read 4 +drop table t1; +# +# Rownum examples from Woqutech +# +set SQL_MODE=ORACLE; +create table t1 (c1 int ,c2 varchar(20)) engine=myisam; +insert into t1 values (1, 'aaa'),(2, 'bbb'),(3, 'ccc'),(4, 'ddd'),(5, 'eee'); +update t1 set c2 = 'xxx' where rownum = 2; +select * from t1 where c2='xxx'; +c1 c2 +update t1 set c2 = 'xxx' where rownum < 3; +select * from t1 where c2='xxx'; +c1 c2 +1 xxx +2 xxx +delete from t1 where rownum = 2; +select count(*) from t1; +count(*) +5 +delete from t1 where rownum < 3; +select count(*) from t1; +count(*) +3 +delete from t1 where c1=rownum ; +select count(*) from t1; +count(*) +3 +delete from t1 where c1=rownum+2 ; +select count(*) from t1; +count(*) +0 +set SQL_MODE=DEFAULT; +drop table t1; +# +# Rownum() used in not supported places (returns 0 or gives an error) +# +set @a=rownum(); +select @a; +@a +0 +create or replace table t (a int, b int as (rownum()) virtual); +ERROR HY000: Function or expression 'rownum()' cannot be used in the GENERATED ALWAYS AS clause of `b` +create table t1 (a int); +insert into t1 values (3),(1),(5),(8),(4); +handler t1 open; +handler t1 read next where rownum() < 1; +ERROR HY000: Function or expression 'rownum()' cannot be used in the WHERE clause of `HANDLER` +handler t1 close; +drop table t1; +create table t1 (a int not null primary key, b int); +insert into t1 values (1,1),(2,2),(3,3); +create function f() returns int return rownum(); +select a, rownum(), f() from t1; +a rownum() f() +1 1 0 +2 2 0 +3 3 0 +drop function f; +drop table t1; +create or replace table t1 (a int, r int); +create trigger tr before update on t1 for each row set NEW.r = rownum(); +insert into t1 (a) values (1),(2); +select * from t1; +a r +1 NULL +2 NULL +update t1 set a=a+10; +select * from t1; +a r +11 0 +12 0 +drop trigger tr; +drop table t1; +# +# LIMIT optimisation +# +create table t1 (a int); +insert into t1 values (1),(2),(3),(4),(5); +flush status; +select * from (select a from t1 where a < 1000) as tt where rownum() <= 2; +a +1 +2 +show status like "Rows_read"; +Variable_name Value +Rows_read 2 +explain extended select * from (select a from t1 where a < 1000) as tt where rownum() <= 2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 limit 2) `tt` where rownum() <= 2 limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000) as tt where rownum() <= 2"; +flush status; +execute stmt; +a +1 +2 +show status like "Rows_read"; +Variable_name Value +Rows_read 2 +flush status; +execute stmt; +a +1 +2 +show status like "Rows_read"; +Variable_name Value +Rows_read 2 +deallocate prepare stmt; +flush status; +select * from (select a from t1 where a < 1000 group by a) as tt where rownum() <= 2; +a +1 +2 +show status like "Rows_read"; +Variable_name Value +Rows_read 5 +explain extended select * from (select a from t1 where a < 1000 group by a) as tt where rownum() <= 2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where; Using temporary; Using filesort +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 group by `test`.`t1`.`a` limit 2) `tt` where rownum() <= 2 limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000 group by a) as tt where rownum() <= 2"; +execute stmt; +a +1 +2 +execute stmt; +a +1 +2 +deallocate prepare stmt; +flush status; +select * from (select a from t1 where a < 1000 group by a order by 1) as tt where rownum() <= 2; +a +1 +2 +show status like "Rows_read"; +Variable_name Value +Rows_read 5 +explain extended select * from (select a from t1 where a < 1000 group by a order by 1) as tt where rownum() <= 2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where; Using temporary; Using filesort +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 group by `test`.`t1`.`a` order by 1 limit 2) `tt` where rownum() <= 2 limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000 group by a order by 1) as tt where rownum() <= 2"; +execute stmt; +a +1 +2 +execute stmt; +a +1 +2 +deallocate prepare stmt; +flush status; +select * from (select a from t1 where a < 1000 union select 10) as tt where rownum() <= 2; +a +1 +2 +show status like "Rows_read"; +Variable_name Value +Rows_read 5 +explain extended select * from (select a from t1 where a < 1000 union select 10) as tt where rownum() <= 2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where +3 UNION NULL NULL NULL NULL NULL NULL NULL NULL No tables used +NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL NULL +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 union /* select#3 */ select 10 AS `10` limit 2) `tt` where rownum() <= 2 limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000 union select 10) as tt where rownum() <= 2"; +execute stmt; +a +1 +2 +execute stmt; +a +1 +2 +deallocate prepare stmt; +# Other limit +select * from (select a from t1 where a < 1000 group by a order by 1 limit 1) as tt where rownum() <= 2; +a +1 +explain extended select * from (select a from t1 where a < 1000 group by a order by 1 limit 1) as tt where rownum() <= 2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where; Using temporary; Using filesort +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 group by `test`.`t1`.`a` order by 1 limit 1) `tt` where rownum() <= 2 limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000 group by a order by 1 limit 1) as tt where rownum() <= 2"; +execute stmt; +a +1 +execute stmt; +a +1 +deallocate prepare stmt; +# Other limit less +select * from (select a from t1 where a < 1000 group by a order by 1 limit 10) as tt where rownum() <= 2; +a +1 +2 +explain extended select * from (select a from t1 where a < 1000 group by a order by 1 limit 10) as tt where rownum() <= 2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where; Using temporary; Using filesort +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 group by `test`.`t1`.`a` order by 1 limit 2) `tt` where rownum() <= 2 limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000 group by a order by 1 limit 10) as tt where rownum() <= 2"; +execute stmt; +a +1 +2 +execute stmt; +a +1 +2 +deallocate prepare stmt; +select * from (select a from t1 where a < 1000 union select 10 limit 1) as tt where rownum() <= 2; +a +1 +explain extended select * from (select a from t1 where a < 1000 union select 10 limit 1) as tt where rownum() <= 2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 5 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where +3 UNION NULL NULL NULL NULL NULL NULL NULL NULL No tables used +NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL NULL +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 union /* select#3 */ select 10 AS `10` limit 1) `tt` where rownum() <= 2 limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000 union select 10 limit 1) as tt where rownum() <= 2"; +execute stmt; +a +1 +execute stmt; +a +1 +deallocate prepare stmt; +# < rownum +select * from (select a from t1 where a < 1000) as tt where rownum() < 2; +a +1 +explain extended select * from (select a from t1 where a < 1000) as tt where rownum() < 2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 limit 1) `tt` where rownum() < 2 limit 1 +prepare stmt from "select * from (select a from t1 where a < 1000) as tt where rownum() < 2"; +execute stmt; +a +1 +execute stmt; +a +1 +deallocate prepare stmt; +# Simple expression +select * from (select a from t1 where a < 1000) as tt where rownum() <= 1+1; +a +1 +2 +explain extended select * from (select a from t1 where a < 1000) as tt where rownum() <= 1+1; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 limit 2) `tt` where rownum() <= <cache>(1 + 1) limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000) as tt where rownum() <= 1+1"; +execute stmt; +a +1 +2 +execute stmt; +a +1 +2 +deallocate prepare stmt; +# Simple expression reversed +select * from (select a from t1 where a < 1000) as tt where 1+1 >= rownum(); +a +1 +2 +explain extended select * from (select a from t1 where a < 1000) as tt where 1+1 >= rownum(); +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00 Using where +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 limit 2) `tt` where <cache>(1 + 1) >= rownum() limit 2 +prepare stmt from "select * from (select a from t1 where a < 1000) as tt where 1+1 >= rownum()"; +execute stmt; +a +1 +2 +execute stmt; +a +1 +2 +deallocate prepare stmt; +# expensive (no opt) +select * from (select a from t1 where a < 1000) as tt where (select max(a) from t1) >= rownum(); +a +1 +2 +3 +4 +5 +explain extended select * from (select a from t1 where a < 1000) as tt where (select max(a) from t1) >= rownum(); +id select_type table type possible_keys key key_len ref rows filtered Extra +1 PRIMARY <derived2> ALL NULL NULL NULL NULL 5 100.00 Using where +3 SUBQUERY t1 ALL NULL NULL NULL NULL 5 100.00 +2 DERIVED t1 ALL NULL NULL NULL NULL 5 100.00 Using where +Warnings: +Note 1003 /* select#1 */ select `tt`.`a` AS `a` from (/* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` < 1000 limit 5) `tt` where (/* select#3 */ select max(`test`.`t1`.`a`) from `test`.`t1`) >= rownum() limit 5 +prepare stmt from "select * from (select a from t1 where a < 1000) as tt where (select max(a) from t1) >= rownum()"; +execute stmt; +a +1 +2 +3 +4 +5 +execute stmt; +a +1 +2 +3 +4 +5 +deallocate prepare stmt; +drop table t1; +# +# Table value constructors +# +values ("first row"),("next row is 3"),(rownum()),("next row is 5"),(rownum()); +first row +first row +next row is 3 +3 +next row is 5 +5 |