Oracle

The first part of Oracle Learning1.oracle Introduction1.1 Common database classification at presentSmall database: SQL Server,access (Microsoft)Medium database: MySQL (Swedish company), Sybase (US Sybase)Large database: Informix (IBM), Oracle

DECLAREV_sqlVARCHAR2( +); V_sql_headVARCHAR2( -); V_sql_tailVARCHAR2(Ten); V_dayVARCHAR2(8); CURSORC_cur is SELECTTo_char ((To_date ('2012-01','yyyy-mm')+(ROWNUM- 1)), 'YYYYMMDD') S_date fromDUAL CONNECT byROWNUMLast_day (To_date ('2012-12','yyyy-mm'

http://blog.csdn.net/weiwenhp/article/details/8094575Directory (?) [-] Use of user name instead How to change the user name The work to be done I want to do something bad. Clear password Many people think that Oracle can

The parameter Parallel_max is the Oracle's largest open parallel service process, the concurrent sum of all sessions.Sql> Show Parameter Parallel_max_serversNAME TYPE VALUE------------------------------------ ----------- -----------------------------

Today company because of business needs, repair to modify a field data type has number (5), changed to number (5,2) typeIf you don't have the data, just use the following statementALTER TABLE Tb_test modify Permile number (5,2);But with the data,

First you have to have a PL/SQL, in fact, there is no line, but this database still has a visual interface for good AH.1. First, log on PL/SQL as the SYS user2. To find out the ID of the table you want to change, take my local data for example, I

Here, we will use the Dbms_random package and case when statement, the idea is as follows:First, the use of dbms_random. The random function randomly generates values and then models the values, and if we want to read them randomly in 10 elements,

As the following table table1:Number of dates (exportdate) (amount)--------------                    -----------1 April-February-08 20October-March-08 21 April-April-08 61 April-June-08 752 April-October-09 231 April-November-09 45April-August-10

Replace is a string substitution in the general senseReplace (C1,C2[,C3])Find the string C2 in the string C1, replacing it with C3. If C3 is empty, all C2 are removed from the C1.UPDATE JD Set id = replace (ID, ' 1 ', ' 2 ');The meaning is to change

Oraclesys_context () function The first parameter is 'userenv', which is fixed. The second parameter is also fixed, but multiple options are fixed. The optional values are as follows:   Select sys_context ('userenv', 'authentication _ type') from

Guarantee of successful installation of oracle11gEnvironment: LSB Version: core-4.0-amd64: core-4.0-noarch: graphics-4.0-amd64: graphics-4.0-noarch: printing-4.0-amd64: printing-4.0-noarch:Distributor ID: RedHatEnterpriseServerDescription: Red Hat

Oracle time format and integer format conversion If the time field of the Oracle database is set to the "NUMBER" type, the query Time column is displayed as a numerical value, such as the "1241450728000" style, which is not readable; if the update

Oracle Database Introduction Oracle getting started Series 4 Oracle Database Overview Finally, we smoothly transitioned to oracle. We hacked Larry once in the first article. here we need to cleanse Larry. After Mr. Qian Zhongshu wrote "besieged city"

Modify the ORACLE field order First, you need to have a pl/SQL statement, but there is still a visual interface for this database. 1. First, log on to PL/SQL as a sys user2. query the ID of the table you want to change. Take my local data as an

Oracle11g installation problem summary Test environment: win7 64-bit flagship edition + jdk7 (64-bit) Installed Software: oracle 11g R2 64-bit After the database is installed according to the general online tutorial, a bunch of problems are found.

Oracleflashback -- returns oracle data and restores data to the specified timestamp Microsoft Windows [version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C: \ Users \ ckz> sqlplus zzjd/zzjd@10.22.1.143/orcl as sysdba;

Basic knowledge about oracle Database 2 Oracle beginners series II Basic Database knowledge This article combs basic database knowledge that has been forgotten, and may not be remembered at all. In either case, remember it. If you cannot remember it,

Modify the column type in oracle1. If the field data is empty, you can directly execute the following command regardless of the field type:Alter table tb modify (name nvarchar2 (20 ));2. If the field has data, you can change it to nvarchar2 (20) and

Five-part oracle learning starter series: memory structure, database structure, and process Oracle getting started Series 5 Memory Structure, database structure, process1. Oracle Database Structure This topic can be found on the Internet, not to

Summary of basic Oracle functions and object examples -- ## Character function, case-sensitive processing function select lower ('abcde') FROM dual; -- ABcDe, all converted to LOWER case select upper ('abcde') FROM dual; -- abcde, convert all to