If you aren't setting a value for that column for a particular row allow the value to be NULL. Then use COALESCE on your table when you retrieve the data. COALESCE will return the first non-null value. So in your case SELECT a, COALESCE(z,y) FROM yourtable If column z has no...
Bug #11557 Default values are set to zero when need to be rounded up to the next magnitude Submitted: 24 Jun 2005 22:38Modified: 12 Jul 2005 11:43 Reporter: Omer Barnir (OCA) Email Updates: Status: Closed Impact on me: None Category: MySQL ServerSeverity: S3 (Non-critical) ...
插入null就是null 超出索引也是插入空值 需要特别注意是set的索引是二进制方式,enum枚举的索引是十进制 root@localhost: 01:36 [7308][db_hlf]>insert into tbl_setenum(setc,enumc)values(1,1),(2,2),(3,3),(4,4),(5,5),(null,null),(0,0); Query OK, 7 rows affected, 2 warnings (0.00 ...
variable value to the compiled-in MySQL default value or a session system variable to the current corresponding global value, set the variable to the valueDEFAULT. For example, the following two statements are identical in setting the session value ofmax_join_sizeto the current global value: ...
mysqlsh> dba.configureInstance('cladmin:cladminpw@localhost:33311') The instance 'example-el7-1644251369:33311' belongs to an InnoDB Cluster. Configuring local MySQL instance listening at port 33311 for use in an InnoDB cluster... This instance reports its own address as ^[[1mexample-el7-16442...
Thank you for the bug report. How you was able to create the table t1 on your sample, in the current source server I got: mysql> create table t1(a int not null default 2, foreign key (a) references t0(a) on update set -> default on delete set default) engine=innodb; ERROR 1005...
2.直接用 set 来改变 MySQL的自动提交模式 set autocommit = 0 禁止自动提交 set autocommit = 1 开启自动提交 说了这么多,我们来写个实例: 这次我们新建一个数据库表来写 mysql> create table star ( -> `id` int unsigned auto_increment, -> `name` varchar(100) not null, ...
If I "needs_database_default", why we need to drop default (sql_alter_column_no_default)? I read we use it to prevent extraneous DROP DEFAULT statements (an example is LONGTEXT in MySQL) because if database is able to use default we need to avoid to drop it. ...
Clientsandother cluster members will communicatewithit through this addressbydefault. If thisisnotcorrect, the report_host MySQLsystemvariable should be changed. Passwordfornewaccount:*** Confirm password:*** applierWorkerThreads will besettothedefaultvalueof4. NOTE:Someconfiguration...
INSERT INTO tableName SET col1='value1', col3='value', col4='value'; and I have a col2 specified to be NOT NULL, the query is accepted anyway. This is on MySQL 4.1. (The same query is not accepted on MySQL 5.0, however we're not ready to move to 5.0 on our production machi...