Oracle

ListaggSelect*from emp Select Listagg(ename,'-')withinGroup(orderby Deptno Desc)from emp; You can see features like Wm_concat, you can customize the connector, the difference:Listagg? : 11G2 only provides functions that do not

1, NVL function.In Oracle: NVL (join_count, 0)MySQL: if (Join_count is null, ' 0 ', join_count)2, string connection."| |" in Oracle Connect with concat in MySQL.3, the system time.In Oracle: Select Sysdate from dualMySQL: Select Sysdate () from dual4

Reference URL:Http://www.2cto.com/database/201203/125539.htmlHttp://www.codesky.net/article/201003/167846.htmlThe first step, on the cmd command line, Sqlplus/nolog# Sqlplus/nolog then enter, Conn/as sysdbasql>conn/as sysdba Second step, view

Dept Department tableClassification of SQL statements1 Data Manipulation Language DMLInsert (record inserted)INSERT INTO Dept (DEPTNO,DEPTNAME,LOC) VALUES (28, ' teaching department ', ' Zhuhai ')Update (Modify record)Update Dept Set deptno=38 where

Install the ORACLE11G database software on redhat5.5 (32bit), install a database, and then log in to the database to create the Scott/tiger testLog in to the database first, where the database is not started[Email protected] oradata]$ Sqlplus/as

When Oracle is ordering NULL, desc defaults to the top of the list, ASC defaults to the top, and when sorting is always inconvenient, you need to think about intervening.Method 1: Use the NVL functionThe NVL function can be added after order by for

$conn = Oci_connect (' 111 ', ' 111 ', "(Description= (address= (PROTOCOL =tcp) (host=10.101.0.36) (PORT = 1521)) (Connect_data = (SID=ORCL))) ");if (! $conn) {$e = Oci_error ();Var_dump ($e [' message ']);Trigger_error (Htmlentities ($e [' message '

' DB ' = = Array (' Db_type ' = ' Oracle ',' Db_host ' = ' 192.168.2.3 ',' Db_name ' = ' (description= (address= (PROTOCOL =tcp) (host=192.168.2.3) (PORT = 1521)) (Connect_data = (SID=ORCL))) " ,' Db_name ' = ' ORCL ',//SID directly written here

--Create a tableCREATE TABLE ABC(ID Number (4) Not null primary key,Username VARCHAR2 () not NULL,PWD VARCHAR2 (+) NOT NULL);--Create a sequenceCreate sequence abc_sequenceIncrement by 1Start with 1MaxValue 9999Cycle NoCache;--Create a triggerCreate

1. Querying the table space names in the database 1) Querying all table spaces Select Tablespace_name from Dba_tablespaces;Select Tablespace_name from User_tablespaces; 2) query The used table space Select

Oracle's goldendate is a software used to do data disaster recovery is commonly known as OGG, of course, can also be used to support the hot backup database, and cross-platform cross-database data migration, specific understanding can be self-Baidu.

1. General processCreate or Replace procedure P1AsBeginDbms_output.put_line (' Hello world ');End--CallCall P1 ();2. Receiving parametersCreate or Replace procedure P2(p_name varchar,p_age in int)Asv_id int;BeginSelect Max (ID) into v_id from stud;V_

3.1.1 HWM (High water Mark)3.1.1.1 definition To manage space, Oracle Database tracks the state of blocks in the segment. The High Water mark (HWM) is the "point" segment beyond which data blocks is unformatted and has never been Used.

1. IntroductionCx_oracle is a Python extension module for connecting and manipulating Oracle databases, supporting versions including Oracle 9.2 10.2 and 11.12. InstallationFinally, to the official website http://cx-oracle.sourceforge.net/installed,

environment variable settings (performed in sqlplus) Create or replace directory filepath as ' D:\ORACLEBACKUP '; Backup script: EXPDP system/[email protected] Directory=filepath dumpfile=ubscorluser20150619.dat logfile=ubscorluser20150619.log

The Oracle Import Utility (utility) allows data to be fetched from the database and written to the operating system files.The basic format used by IMP: imp[username[/password[@service]], the following examples illustrate the common use of IMP.1. Get

Modifying the Oracle Character setMethod/Step Character set changes for Oracle databasesA, Oracle server-side Character set querySelect Userenv (' language ') from dualWhere Nls_characterset is the server-side character setNls_language for

Oracle Stored Procedure learning notesStored Procedure A stored procedure is a type of block named pl/SQL. It can be assigned parameters and stored in a database and can be called by users.The stored procedure is compiled code, so you do not have to

New Feature of oracle11g-SQLPlanManagement (SPM) 1. Introduction Oracle Database11gR1 introduces SQL PlanManagement (SPM), a new tool that allows DBA to capture and maintain the optimal execution plan for any SQL statement. This restricts the

Oracle BASICS (1) Oracle Database System is a group of software products with distributed databases as the core provided by Oracle in the United States. It is currently the most popular Client/Server) or one of the databases in the B/S architecture.