trigger.result

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

drop table if exists t1, t2, t3, t4;
drop view if exists v1;
drop database if exists mysqltest;
drop function if exists f1;
drop function if exists f2;
drop procedure if exists p1;
create table t1 (i int);
create trigger trg before insert on t1 for each row set @a:=1;
set @a:=0;
select @a;
@a
0
insert into t1 values (1);
select @a;
@a
1
drop trigger trg;
create trigger trg before insert on t1 for each row set @a:=new.i;
insert into t1 values (123);
select @a;
@a
123
drop trigger trg;
drop table t1;
create table t1 (i int not null, j int);
create trigger trg before insert on t1 for each row 
begin 
if isnull(new.j) then
set new.j:= new.i * 10;
end if;
end|
insert into t1 (i) values (1)|
insert into t1 (i,j) values (2, 3)|
select * from t1|
i	j
1	10
2	3
drop trigger trg|
drop table t1|
create table t1 (i int not null primary key);
create trigger trg after insert on t1 for each row 
set @a:= if(@a,concat(@a, ":", new.i), new.i);
set @a:="";
insert into t1 values (2),(3),(4),(5);
select @a;
@a
2:3:4:5
drop trigger trg;
drop table t1;
create table t1 (aid int not null primary key, balance int not null default 0);
insert into t1 values (1, 1000), (2,3000);
create trigger trg before update on t1 for each row 
begin
declare loc_err varchar(255);
if abs(new.balance - old.balance) > 1000 then
set new.balance:= old.balance;
set loc_err := concat("Too big change for aid = ", new.aid);
set @update_failed:= if(@update_failed, concat(@a, ":", loc_err), loc_err);
end if;
end|
set @update_failed:=""|
update t1 set balance=1500|
select @update_failed;
select * from t1|
@update_failed
Too big change for aid = 2
aid	balance
1	1500
2	3000
drop trigger trg|
drop table t1|
create table t1 (i int);
insert into t1 values (1),(2),(3),(4);
create trigger trg after update on t1 for each row 
set @total_change:=@total_change + new.i - old.i;
set @total_change:=0;
update t1 set i=3;
select @total_change;
@total_change
2
drop trigger trg;
drop table t1;
create table t1 (i int);
insert into t1 values (1),(2),(3),(4);
create trigger trg before delete on t1 for each row 
set @del_sum:= @del_sum + old.i;
set @del_sum:= 0;
delete from t1 where i <= 3;
select @del_sum;
@del_sum
6
drop trigger trg;
drop table t1;
create table t1 (i int);
insert into t1 values (1),(2),(3),(4);
create trigger trg after delete on t1 for each row set @del:= 1;
set @del:= 0;
delete from t1 where i <> 0;
select @del;
@del
1
drop trigger trg;
drop table t1;
create table t1 (i int, j int);
create trigger trg1 before insert on t1 for each row 
begin
if new.j > 10 then
set new.j := 10;
end if;
end|
create trigger trg2 before update on t1 for each row 
begin
if old.i % 2 = 0 then
set new.j := -1;
end if;
end|
create trigger trg3 after update on t1 for each row 
begin
if new.j = -1 then
set @fired:= "Yes";
end if;
end|
set @fired:="";
insert into t1 values (1,2),(2,3),(3,14);
select @fired;
@fired

select * from t1;
i	j
1	2
2	3
3	10
update t1 set j= 20;
select @fired;
@fired
Yes
select * from t1;
i	j
1	20
2	-1
3	20
drop trigger trg1;
drop trigger trg2;
drop trigger trg3;
drop table t1;
create table t1 (id int not null primary key, data int);
create trigger t1_bi before insert on t1 for each row
set @log:= concat(@log, "(BEFORE_INSERT: new=(id=", new.id, ", data=", new.data,"))");
create trigger t1_ai after insert on t1 for each row
set @log:= concat(@log, "(AFTER_INSERT: new=(id=", new.id, ", data=", new.data,"))");
create trigger t1_bu before update on t1 for each row
set @log:= concat(@log, "(BEFORE_UPDATE: old=(id=", old.id, ", data=", old.data,
") new=(id=", new.id, ", data=", new.data,"))");
create trigger t1_au after update on t1 for each row
set @log:= concat(@log, "(AFTER_UPDATE: old=(id=", old.id, ", data=", old.data,
") new=(id=", new.id, ", data=", new.data,"))");
create trigger t1_bd before delete on t1 for each row
set @log:= concat(@log, "(BEFORE_DELETE: old=(id=", old.id, ", data=", old.data,"))");
create trigger t1_ad after delete on t1 for each row
set @log:= concat(@log, "(AFTER_DELETE: old=(id=", old.id, ", data=", old.data,"))");
set @log:= "";
insert into t1 values (1, 1);
select @log;
@log
(BEFORE_INSERT: new=(id=1, data=1))(AFTER_INSERT: new=(id=1, data=1))
set @log:= "";
insert ignore t1 values (1, 2);
select @log;
@log
(BEFORE_INSERT: new=(id=1, data=2))
set @log:= "";
replace t1 values (1, 3), (2, 2);
select @log;
@log
(BEFORE_INSERT: new=(id=1, data=3))(BEFORE_UPDATE: old=(id=1, data=1) new=(id=1, data=3))(AFTER_UPDATE: old=(id=1, data=1) new=(id=1, data=3))(BEFORE_INSERT: new=(id=2, data=2))(AFTER_INSERT: new=(id=2, data=2))
alter table t1 add ts timestamp default now();
set @log:= "";
replace t1 (id, data) values (1, 4);
select @log;
@log
(BEFORE_INSERT: new=(id=1, data=4))(BEFORE_DELETE: old=(id=1, data=3))(AFTER_DELETE: old=(id=1, data=3))(AFTER_INSERT: new=(id=1, data=4))
set @log:= "";
insert into t1 (id, data) values (1, 5), (3, 3) on duplicate key update data= data + 2;
select @log;
@log
(BEFORE_INSERT: new=(id=1, data=5))(BEFORE_UPDATE: old=(id=1, data=4) new=(id=1, data=6))(AFTER_UPDATE: old=(id=1, data=4) new=(id=1, data=6))(BEFORE_INSERT: new=(id=3, data=3))(AFTER_INSERT: new=(id=3, data=3))
drop table t1;
create table t1 (id int primary key, data varchar(10), fk int);
create table t2 (event varchar(100));
create table t3 (id int primary key);
create trigger t1_ai after insert on t1 for each row 
insert into t2 values (concat("INSERT INTO t1 id=", new.id, " data='", new.data, "'"));
insert into t1 (id, data) values (1, "one"), (2, "two");
select * from t1;
id	data	fk
1	one	NULL
2	two	NULL
select * from t2;
event
INSERT INTO t1 id=1 data='one'
INSERT INTO t1 id=2 data='two'
drop trigger t1_ai;
create trigger t1_bi before insert on t1 for each row
begin
if exists (select id from t3 where id=new.fk) then
insert into t2 values (concat("INSERT INTO t1 id=", new.id, " data='", new.data, "' fk=", new.fk));
else
insert into t2 values (concat("INSERT INTO t1 FAILED id=", new.id, " data='", new.data, "' fk=", new.fk));
set new.id= NULL;
end if;
end|
insert into t3 values (1);
insert into t1 values (4, "four", 1), (5, "five", 2);
ERROR 23000: Column 'id' cannot be null
select * from t1;
id	data	fk
1	one	NULL
2	two	NULL
4	four	1
select * from t2;
event
INSERT INTO t1 id=1 data='one'
INSERT INTO t1 id=2 data='two'
INSERT INTO t1 id=4 data='four' fk=1
INSERT INTO t1 FAILED id=5 data='five' fk=2
drop table t1, t2, t3;
create table t1 (id int primary key, data varchar(10));
create table t2 (seq int);
insert into t2 values (10);
create function f1 () returns int return (select max(seq) from t2);
create trigger t1_bi before insert on t1 for each row
begin
if new.id > f1() then
set new.id:= f1();
end if;
end|
insert into t1 values (1, "first");
insert into t1 values (f1(), "max");
select * from t1;
id	data
1	first
10	max
drop table t1, t2;
drop function f1;
create table t1 (id int primary key, fk_t2 int);
create table t2 (id int primary key, fk_t3 int);
create table t3 (id int primary key);
insert into t1 values (1,1), (2,1), (3,2);
insert into t2 values (1,1), (2,2);
insert into t3 values (1), (2);
create trigger t3_ad after delete on t3 for each row
delete from t2 where fk_t3=old.id;
create trigger t2_ad after delete on t2 for each row
delete from t1 where fk_t2=old.id;
delete from t3 where id = 1;
select * from t1 left join (t2 left join t3 on t2.fk_t3 = t3.id) on t1.fk_t2 = t2.id;
id	fk_t2	id	fk_t3	id
3	2	2	2	2
drop table t1, t2, t3;
create table t1 (id int primary key, copy int);
create table t2 (id int primary key, data int);
insert into t2 values (1,1), (2,2);
create trigger t1_bi before insert on t1 for each row
set new.copy= (select data from t2 where id = new.id);
create trigger t1_bu before update on t1 for each row
set new.copy= (select data from t2 where id = new.id);
insert into t1 values (1,3), (2,4), (3,3);
update t1 set copy= 1 where id = 2;
select * from t1;
id	copy
1	1
2	2
3	NULL
drop table t1, t2;
create table t1 (i int);
create table t3 (i int);
create trigger trg before insert on t1 for each row set @a:= old.i;
ERROR HY000: There is no OLD row in on INSERT trigger
create trigger trg before delete on t1 for each row set @a:= new.i;
ERROR HY000: There is no NEW row in on DELETE trigger
create trigger trg before update on t1 for each row set old.i:=1;
ERROR HY000: Updating of OLD row is not allowed in trigger
create trigger trg before delete on t1 for each row set new.i:=1;
ERROR HY000: There is no NEW row in on DELETE trigger
create trigger trg after update on t1 for each row set new.i:=1;
ERROR HY000: Updating of NEW row is not allowed in after trigger
create trigger trg before update on t1 for each row set new.j:=1;
ERROR 42S22: Unknown column 'j' in 'NEW'
create trigger trg before update on t1 for each row set @a:=old.j;
ERROR 42S22: Unknown column 'j' in 'OLD'
create trigger trg before insert on t2 for each row set @a:=1;
ERROR 42S02: Table 'test.t2' doesn't exist
create trigger trg before insert on t1 for each row set @a:=1;
create trigger trg after insert on t1 for each row set @a:=1;
ERROR HY000: Trigger already exists
create trigger trg2 before insert on t1 for each row set @a:=1;
ERROR HY000: Trigger already exists
create trigger trg before insert on t3 for each row set @a:=1;
ERROR HY000: Trigger already exists
create trigger trg2 before insert on t3 for each row set @a:=1;
drop trigger trg2;
drop trigger trg;
drop trigger trg;
ERROR HY000: Trigger does not exist
create view v1 as select * from t1;
create trigger trg before insert on v1 for each row set @a:=1;
ERROR HY000: 'test.v1' is not BASE TABLE
drop view v1;
drop table t1;
drop table t3;
create temporary table t1 (i int);
create trigger trg before insert on t1 for each row set @a:=1;
ERROR HY000: Trigger's 't1' is view or temporary table
drop table t1;
create table t1 (x1col char);
create trigger tx1 before insert on t1 for each row set new.x1col = 'x';
insert into t1 values ('y');
drop trigger tx1;
drop table t1;
create table t1 (i int) engine=myisam;
insert into t1 values (1), (2);
create trigger trg1 before delete on t1 for each row set @del_before:= @del_before + old.i;
create trigger trg2 after delete on t1 for each row set @del_after:= @del_after + old.i;
set @del_before:=0, @del_after:= 0;
delete from t1;
select @del_before, @del_after;
@del_before	@del_after
3	3
drop trigger trg1;
drop trigger trg2;
drop table t1;
create table t1 (a int);
create trigger trg1 before insert on t1 for each row set new.a= 10;
drop table t1;
create table t1 (a int);
insert into t1 values ();
select * from t1;
a
NULL
drop table t1;
create database mysqltest;
use mysqltest;
create table t1 (i int);
create trigger trg1 before insert on t1 for each row set @a:= 1;
drop database mysqltest;
use test;
create database mysqltest;
create table mysqltest.t1 (i int);
create trigger trg1 before insert on mysqltest.t1 for each row set @a:= 1;
ERROR HY000: Trigger in wrong schema
use mysqltest;
create trigger test.trg1 before insert on t1 for each row set @a:= 1;
ERROR HY000: Trigger in wrong schema
drop database mysqltest;
use test;
create table t1 (i int, j int default 10, k int not null, key (k));
create table t2 (i int);
insert into t1 (i, k) values (1, 1);
insert into t2 values (1);
create trigger trg1 before update on t1 for each row set @a:= @a + new.j - old.j;
create trigger trg2 after update on t1 for each row set @b:= "Fired";
set @a:= 0, @b:= "";
update t1, t2 set j = j + 10 where t1.i = t2.i;
select @a, @b;
@a	@b
10	Fired
insert into t1 values (2, 13, 2);
insert into t2 values (2);
set @a:= 0, @b:= "";
update t1, t2 set j = j + 15 where t1.i = t2.i and t1.k >= 2;
select @a, @b;
@a	@b
15	Fired
create trigger trg3 before delete on t1 for each row set @c:= @c + old.j;
create trigger trg4 before delete on t2 for each row set @d:= @d + old.i;
create trigger trg5 after delete on t1 for each row set @e:= "After delete t1 fired";
create trigger trg6 after delete on t2 for each row set @f:= "After delete t2 fired";
set @c:= 0, @d:= 0, @e:= "", @f:= "";
delete t1, t2 from t1, t2 where t1.i = t2.i;
select @c, @d, @e, @f;
@c	@d	@e	@f
48	3	After delete t1 fired	After delete t2 fired
drop table t1, t2;
create table t1 (i int, j int default 10)|
create table t2 (i int)|
insert into t2 values (1), (2)|
create trigger trg1 before insert on t1 for each row 
begin
if new.i = 1 then
set new.j := 1;
end if;
end|
create trigger trg2 after insert on t1 for each row set @a:= 1|
set @a:= 0|
insert into t1 (i) select * from t2|
select * from t1|
i	j
1	1
2	10
select @a|
@a
1
drop table t1, t2|
create table t1 (i int, j int, k int);
create trigger trg1 before insert on t1 for each row set new.k = new.i;
create trigger trg2 after insert on t1 for each row set @b:= "Fired";
set @b:="";
load data infile '../std_data_ln/rpl_loaddata.dat' into table t1 (@a, i);
select *, @b from t1;
i	j	k	@b
10	NULL	10	Fired
15	NULL	15	Fired
set @b:="";
load data infile '../std_data_ln/loaddata5.dat' into table t1 fields terminated by '' enclosed by '' (i, j);
select *, @b from t1;
i	j	k	@b
10	NULL	10	Fired
15	NULL	15	Fired
1	2	1	Fired
3	4	3	Fired
5	6	5	Fired
drop table t1;
create table t1 (i int, at int, k int, key(k)) engine=myisam;
create table t2 (i int);
insert into t1 values (1, 1, 1);
insert into t2 values (1), (2), (3);
create trigger ai after insert on t1 for each row set @a:= new.at;
create trigger au after update on t1 for each row set @a:= new.at;
create trigger ad after delete on t1 for each row set @a:= old.at;
alter table t1 drop column at;
select * from t1;
i	k
1	1
insert into t1 values (2, 1);
ERROR 42S22: Unknown column 'at' in 'NEW'
select * from t1;
i	k
1	1
2	1
update t1 set k = 2 where i = 2;
ERROR 42S22: Unknown column 'at' in 'NEW'
select * from t1;
i	k
1	1
2	2
delete from t1 where i = 2;
ERROR 42S22: Unknown column 'at' in 'OLD'
select * from t1;
i	k
1	1
load data infile '../std_data_ln/loaddata5.dat' into table t1 fields terminated by '' enclosed by '' (i, k);
ERROR 42S22: Unknown column 'at' in 'NEW'
select * from t1;
i	k
1	1
1	2
insert into t1 select 3, 3;
ERROR 42S22: Unknown column 'at' in 'NEW'
select * from t1;
i	k
1	1
1	2
3	3
update t1, t2 set k = k + 10 where t1.i = t2.i;
ERROR 42S22: Unknown column 'at' in 'NEW'
select * from t1;
i	k
1	11
1	2
3	3
update t1, t2 set k = k + 10 where t1.i = t2.i and k < 3;
ERROR 42S22: Unknown column 'at' in 'NEW'
select * from t1;
i	k
1	11
1	12
3	3
delete t1, t2 from t1 straight_join t2 where t1.i = t2.i;