drop table if exists t1;
SET SQL_SAFE_UPDATES=1,SQL_SELECT_LIMIT=4, SQL_MAX_JOIN_SIZE=9;
create table t1 (a int primary key, b char(20));
insert into t1 values(1,"test");
SELECT SQL_BUFFER_RESULT * from t1;
a	b
1	test
update t1 set b="a" where a=1;
delete from t1 where a=1;
insert into t1 values(1,"test"),(2,"test2");
SELECT SQL_BUFFER_RESULT * from t1;
a	b
1	test
2	test2
update t1 set b="a" where a=1;
select 1 from t1,t1 as t2,t1 as t3,t1 as t4;
1
1
1
1
1
update t1 set b="a";
You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column
update t1 set b="a" where b="test";
You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column
delete from t1;
You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column
delete from t1 where b="test";
You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column
delete from t1 where a+0=1;
You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column
select 1 from t1,t1 as t2,t1 as t3,t1 as t4,t1 as t5;
The SELECT would examine too many records and probably take a very long time. Check your WHERE and use SET OPTION SQL_BIG_SELECTS=1 if the SELECT is ok
update t1 set b="a" limit 1;
update t1 set b="a" where b="b" limit 2;
delete from t1 where b="test" limit 1;
delete from t1 where a+0=1 limit 2;
drop table t1;
SET SQL_SAFE_UPDATES=0,SQL_SELECT_LIMIT=DEFAULT, SQL_MAX_JOIN_SIZE=DEFAULT;