Oracle

1. subqueries nest another SQL statement in one SQL statement into subqueries. When a problem cannot be solved through one clause, subqueries can be considered. A subquery that appears in the FROM clause of the SELECT statement is called "embedded

Batch deletion of ORACLE table stored procedures often requires deletion of some tables during database management, but manual deletion is time-consuming and laborious. You can modify and use the following stored procedures according to the

Common oracle and sqlserver functions: decode (c1, A, y1, B, y2 ....) // c1 is the prerequisite, A is the comparison object, y1 is the result object, B is the comparison object, and y2 is the result object. Equivalent to case when (..) and (..) then

The following error is reported during the installation of ORACLE 11G Due to configuration reasons:After following the installation prompt, when PL/SQL DEVELOPER is enabled to connect to the database, the ORA-12514: TNS: The Listener cannot identify

1. log on to my Objecttools --> Browser Filter by default. In the displayed window, select defalut 2 in my object. log on to the password and automatically save tools --> Preferences --> Logon History check store with password www.2cto.com 3. press

Fully uninstall Oracle 9I software environment in Windows XP: 1 Windows XP + oracle 9i2 Oracle installation path: E:/oracle start uninstall: 1 start --> set --> control panel --> management tools --> services --> stop all oracle Services 2 start -->

ORACLE 11g Automatic Memory Management: in oracle 11g, the SGA and PGA components can be automatically allocated based on the workload by using the memory_target parameter. Oracle recommends using automatic memory management to simplify memory

Version: 11g port: 1521 Installation File:/install/linux.x64_11gR2_database_1of2.zip, linux.x64_11gr2_database204 f2.zip www.2cto.com installation process: the installation process is centos without a graphical interface. Tool used: ssh + xmanager.

Dba_users Database user Information dba_segments table segment information dba_extents data zone starting with dba _, user _, v $ _, all _, session _, and index _ in oracle information dba_objects database object information dba_tablespaces database

Create a simple trigger exercise environment in Oracle: PLSQL Developer 7.1.5 + Oracle 11.2.0 problem: Use PLSQL Developer in Oracle to create a simple trigger. Solution: Step 1: Find the Triggers in the My Objects expanded list on the left of PLSQL

Oracle deadlock session processing method when a deadlock occurs in Oracle, the Operation deadlock data will remain in the waiting state. The specific solution is as follows: Query all deadlocks: 1 SELECT * from v $ LOCK; query all sessions: 1

/* Total number of patients with high disease in the administrative village of the Production and Marketing institution the number of high-severity patients managed this month (one service per year) the number of high-severity patients managed this

ORACLE date _: submitdate = DateTime. parse (submitdate ). toString ("d-M month-yyyy"); current time: sysdate () to_date ('2017-01-02 ', 'yyyy-M-dd') www.2cto.com select count (1) from L_PERM where CANCEL <> 'y' and (sysdate-perm_date)> 3 debug and

Related Links: Exploring the RMAN_01 concept of ORACLE http://www.bkjia.com/database/201205/132243.html Explore the basic use of RMAN_02 in ORACLE http://www.bkjia.com/database/201205/132329.html As mentioned earlier, backups are classified into

Combined Query, as its name implies, combines two or more tables to perform complex queries. The combined query is a bit similar to the high mathematics: Set. It is further divided into: full set, subset, union, and intersection. Preview the tables

N records are randomly extracted from Oracle. 1. Random data is retrieved from Oracle.1. Basic methods for accessing data from Oracle: 1) Full table Scan: perform Full table Scan and read all records from the Oracle table, check whether each row

Reset set linesize 200 ------------------------------------ display the width of the buffer text desc user_tables; ----------------------------------- display all the table fields and structure alter table TABLE2 modify column name date; ------------

1. Logon: 1. sqlplus enter the user password as prompted, but there is no place to enter the database connection string. You need to set ORACLE_SID in advance. 2. sqlplus user/pass @ db log on directly. The disadvantage is that the password may be

Oracle _ users only have permission to access other USER views -- CREATE user lf identified by lf profile default tablespace user temporary tablespace temp account unlock; -- grant permission to create session to query_dqb; grant select on

Create a tablespace in oracle, user and import/export // create a temporary tablespace create temporary tablespace test_temp tempfile 'e: \ oracle \ product \ 10.2.0 \ oradata \ testserver \ test_temp01.dbf 'size 32 m www.2cto.com autoextend on next