how to change primary monitor

insert a value of INSERT into test1 values (' 1′, ' We love you very much '); The column was then modified: ALTER TABLE test1 Modify (name VARCHAR2 (8)); You will get the error: Error on line 2nd: ORA-01441: Cannot reduce column length because some values are too large --------------------------------------------------------------------------------------------------------------- Advanced usage: Renaming a table ALTER TABLE table_name RENAME to New_table_name; Modify the name of a column Syntax

--alter table Historydata Drop constraint pk_historydata--delete primary keyALTER TABLE HISTORYDATA ADD constraint Pk_historydata primary KEY (Collectiontime,code)--Change primary keyDelete from Historydata where collectiontime between ' 2014-09-01 00:00:00 ' and ' 2014-11-01 00:00:00 ' and ID not in (Select ID from (S

Insert on Dumplicate Update when the primary key is the same update, the contents of the update change to 1 Multiple contents of update are separated by commas ... And notmysql> insert INTO ' 200702 ' (' Domain ', ' 2nd_domain ', ' TLD ', ' query_ns1 ', ' query_ns2 ', ' report_date ') VALUES (' DNSPOD.C Om ', ' dnspod ', ' com ', 1000, Watts, ' 2007-02-04 ') on DUPLICATE KEY UPDATE ' query_ns1 ' = ' query

=NewSqlsessionfactorybuilder (). build (reader); //provides a way to get to the session Public StaticSqlsession getsession ()throwsioexception{System.out.println ("22222" +factory); //The disadvantage is that the factory is//What the hell did 1.1 opensession do?sqlsession session =factory.opensession (); System.out.println ("3333"); returnsession; }}Single Test　　 Public classMyTest {Istudentdao dao; @Before Public voidInitData ()throwsioexception{DAO=NewStudentdaoimpl (); } /*** Fuzz

Company all servers finally put to the same room, opened the intranet access. This way, you have to change the configuration of some MySQL from the server and become intranet access. BackupThe first is to shut down the MySQL server (slave end) and backup configuration information The code is as follows Copy Code Service Mysqld Stop The code is as follows Copy Code #进入到mysql目录Cd/var/li