Oracle

Oracle "CONNECT by" is a hierarchical query clause that is typically used for queries of tree or hierarchical result sets. Its syntax is:[START with condition] CONNECT by [Nocycle] ConditionDescription1. Start with: Tells the system which node to

http://blog.csdn.net/xiaoyao6650/article/details/4027041View Processes#当前的连接数Select COUNT (*) from v$process;#数据库允许的连接数Select value from v$parameter where name = ' processes ';#查看连接配置信息Show parameter processes;#修改Connection number alter system set

ORM "Object Relational Mapping", that is, object-relational mapping, is to map a row of a relational database to an object, that is, a class corresponding to a table, so that the code is simpler to write, do not directly manipulate the SQL statement.

Oracle data import and export imp/exp is equivalent to Oracle data restore and backup. The EXP command can export data from a remote database server to a local DMP file, and the IMP command can import the DMP file from a local to a distant database

Scenario 1: Close the database and restart.Scenario 2:Alter user XXX account lock;SELECT * from v$session WHERE username= ' lgdb ';Alter system kill session ' xx,xx ' drop user xx cascade;(1) View the user's connection statusSelect

This article from the following aspects of the concept and operation of the partition table: 1. Table space and the concept of partitioned Tables 2. Table partitioning's specific role 3. Table partitioning's advantages and disadvantages 4. Table

1, to unlock the userAlter user Scott account unlock;2, log off, disconnect, switch the current user connectionQuitConn Scott/tiger3, User rights queryA. View all Users:SELECT * from Dba_users;SELECT * from All_users;SELECT * from User_users;B. View

I want to do two sets of RAC between the data guard, because Datafile,controlfile, even archivelog are stored in ASM, the direct copy of the data is a bit unrealistic, ASM disk is always to use, so want to do from a library Rman full backup, Then

In Oracle, an empty string is treated as NULL, and any value with a null comparison result is null. As a result, an exception occurs when you compare two strings. Take a look at the following example:declare     I VARCHAR2: = null;    v VARCHAR2

Http://www.linuxidc.com/Linux/2014-02/97335.htmThe first two days of leadership gave a live, database migration, the original system is used by the Oracle database, now to change to MySQL, then did not think about the next, the original system with

First, install the configuration Oracle ClientTo access Orcale data, the Oracle client must be installed on the client machine that is accessed.Orcale has two forms of client:L Complete ClientThe Microsoft OLE DB provider that includes basic Oracle

One, from Oracle everywhere data to Excel filesMethod one, directly from PL/SQL, select All data, and then copy and paste into Excel;Method Two, also through PL/SQL, in the data column, right-click Export Results--select CSV. Because CSV is the

Oracle EBSGetting StartedOracle EBSFull name isOraclee-commerce Suite (e-business Suit), was in the originalApplication(ERP) is based on an extension that containsERP(Enterprise Resource Planning management),HR(Human resources management),CRMA

Use DateOracle Internal use digital storage date: century, year, month, day, hour, minute, second.The default date display format is DD-MON-RR.--You can specify only the post-two bits of the year, allowing the 21st century date to be stored in 21st

Issue: Win8 on a 64-bit system that uses PLSQL developer to connect to a local Oracle database can cause an inexplicable problem, and the error box may even be empty.Reason: According to the internet, the reason is estimated to install 64-bit Oracle

1. Select queryA single SELECT statementRetrieving data from a database through select in PL/sql:Grammar: must use the INTO clause query must and can only return one row can use the full select syntax Using the Select

In the online search for a lot of time stamps through Oracle generation method, most of them are more complex, the following method should be relatively simple, and can achieve the second and millisecond time stamp, recommend: Seconds-time

DDL(data definition Language) Definition language:CREATE ALTER DROP ObjectTRUNCATE table name;DML(Data manipulation language) manipulation language:INSERT UPDATE DELETE SELECTCommon Oracle database Objects :User tablespace table View index sequence

select * from T_user where user_name like CONCAT ('% ', #{search_name}, '% ') select * from T_user where user_name like '% ' | | #{search_name}| | ' % ' select * from T_user where user_name like CONCAT ('% ', #{search_name}, '% ') select * from

Oracle Error Log: ORA-00257, oracleora-00257 The following error is reported when the program is started this afternoon: Caused by: java. SQL. SQLException: ORA-00257: archive program error. Only internal connections are allowed before release. It