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(a) Table1. TableTo create a table:Create Table Number varchar2 ());--Add a new column:Alter Table add photo blob;--Modify ColumnsAlter Table varchar2 (a);--Delete ColumnsAlter Table Drop column photo;--Rename ColumnsAlter Table column to username;

In view of some of the more bizarre Oracle problems, I have not met can not help to solve. And more anxious to catch up with the time of the pro, I can only recommend unloading in the installation of the method, the general time is also 1 hours to 1.

"Article Summary"A recent project to get some data that exists on other servers, it is implemented in a way that is pushed by other "servers" to our servers for security reasons. Our server is using SQL Server R2, the other "servers" are using SQL

To completely uninstall the oracle11g step:1. Start-> Settings-> Control Panel-> Management Tool-> Service stop all Oracle services.2, Start-> Program->oracle-orahome81->oracle installation products-> Universal Installer, click "Uninstall

In the company's development, to ensure that the scalability of the server to expand the market needs of enterprises have an important role, therefore, this to the architect put forward some requirements. Octivi co-founder and software architect

The Oracle Supplemental logging feature can be divided into the following types of functions: Minimum (Minimal), support for all fields (all), primary key (primary key), unique key support (unique), support for foreign keys ( Foreign key). field

Transferred from: http://www.cnblogs.com/zwq194/archive/2012/09/21/2696490.htmlFirst, uninstall Oracle before oracle11g there is a situation where uninstalling is not clean, causing the installation to fail again, running services.msc to open the

Ensureindex () methodTo create an index, you need to use the Ensureindex () method of MongoDB.Grammar:The basic syntax for the Ensureindex () method is as follows yiibai.com >db. Collection_name. Ensureindex({KEY:1 The key here is to

Start the corresponding SERVER:CD: Mongod--dbpath db Path to the Mangodb installation root directoryTo create the MANGODB service:Mongod.exe--logpath d:/mongodb/logs/mongodb.log--logappend--dbpath d:/mongodb/db--directoryperdb--serviceName

Original from " NoSQL Data Modeling techniques ", compiled by the cool shell net Chenhao NoSQL Data Modeling Technology ". After reading this article, you may feel a little bit about NOSQL data structures. My feeling is that the relational database

This article goes on to the above four articles to continue to describe the Shard cluster construction under the window platform MongoDB. Indexes can also be created in a shard cluster in the same way that indexes are created in a separate database.

Oracle | PL/SQL Unique index (unique Constraint) usage1 GoalsExamples show how to create, delete, disable, and use uniqueness constraints.2 What is a uniqueness constraint? A uniqueness constraint is a constraint that combines a field in a table or

First, demand analysisWith the growing Internet technology, the number of servers is also increasing, from the initial several servers to a large data center, alone can not meet in the technology, business, management and other aspects of the

Installation of Oracle database This is not the case, there should be many online, but the Oracle database uninstallation can not find a more detailed description of the complete uninstall. A lot of uninstallation is incomplete, there will be legacy

Files and directories Common command target View Catalog Contents ls Switch directories cd Create and delete operations touch rm mkdir Copying and moving files

InnoDB and MyISAM are the two most common table types used by many people when using MySQL, both of which have pros and cons, depending on the application. The basic difference is that the MyISAM type does not support advanced processing such as

To completely uninstall the oracle11g step:1. Start-> Settings-> Control Panel-> Management Tool-> Service stop all Oracle services.2, Start-> Program->oracle-orahome81->oracle installation products-> Universal Installer, click "Uninstall

The concept of time stamp has been vague, I believe a lot of friends will be mistaken: Timestamp is a Time field, each time you add data, fill in the current time value. In fact, this misled a lot of friends.1. Basic Concepts Timestamp: A unique

To completely uninstall the oracle11g step:1. Start-> Settings-> Control Panel-> Management Tool-> Service stop all Oracle services.2, Start-> Program->oracle-orahome81->oracle installation products-> Universal Installer, click "Uninstall

Database Supplemental log information was lost after rebuilding the control file (Missed supplemental log information)Reference text:Missed Database supplemental Log information after recreate Controlfile in 10g database. (Doc ID 1474952.1)Suitable