mirror of
https://github.com/MariaDB/server.git
synced 2025-11-03 14:33:32 +03:00
23145cfed7
bmove_allign -> bmove_align Added OLAP function ROLLUP Split mysql_fix_privilege_tables to a script and a .sql data file Added new (MEMROOT*) functions to avoid calling current_thd() when creating some common objects. Added table_alias_charset, for easier --lower-case-table-name handling Better SQL_MODE handling (Setting complex options also sets sub options) New (faster) assembler string functions for x86
33 lines
1.4 KiB
Plaintext
33 lines
1.4 KiB
Plaintext
drop table if exists t1,t2;
|
|
set @a := foo;
|
|
ERROR 42S22: Unknown column 'foo' in 'field list'
|
|
set @a := connection_id() + 3;
|
|
select @a - connection_id();
|
|
@a - connection_id()
|
|
3
|
|
CREATE TABLE t1 ( i int not null, v int not null,index (i));
|
|
insert into t1 values (1,1),(1,3),(2,1);
|
|
create table t2 (i int not null, unique (i));
|
|
insert into t2 select distinct i from t1;
|
|
select * from t2;
|
|
i
|
|
1
|
|
2
|
|
select distinct t2.i,@vv1:=if(sv1.i,1,0),@vv2:=if(sv2.i,1,0),@vv3:=if(sv3.i,1,0), @vv1+@vv2+@vv3 from t2 left join t1 as sv1 on sv1.i=t2.i and sv1.v=1 left join t1 as sv2 on sv2.i=t2.i and sv2.v=2 left join t1 as sv3 on sv3.i=t2.i and sv3.v=3;
|
|
i @vv1:=if(sv1.i,1,0) @vv2:=if(sv2.i,1,0) @vv3:=if(sv3.i,1,0) @vv1+@vv2+@vv3
|
|
1 1 0 1 2
|
|
2 1 0 0 1
|
|
explain select * from t1 where i=@vv1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref i i 4 const 1 Using where
|
|
explain select * from t1 where @vv1:=@vv1+1 and i=@vv1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using where
|
|
explain select @vv1:=i from t1 where i=@vv1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 index NULL i 4 NULL 3 Using where; Using index
|
|
explain select * from t1 where i=@vv1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref i i 4 const 1 Using where
|
|
drop table t1,t2;
|