Alter In Database

ALTER alter alter the name of the table structure of the name of the table ALTER TABLE ALTER TABLE ALTER TABLE statement is used to add, modify or delete columns in the existing table. sql alter table syntax To add a column to a table, use the following syntax: alter table table_name add column_name datatype To delete a column in a table, use the following syntax: alter table table _...

With the popularity of the Internet and the continuous development of network technology, the confidentiality requirements of data are more and more high. In the usual server/client mode mis development, because the program to maintain the connection with the database server, for the flexibility and extensibility of the program, the join parameters (user ID and login password) can not be written in the program death (in fact, writing death is not a good way), There are two kinds of general methods: one is to store the join parameters in the registry, and the other is to read the INI file directly. And the safety of several methods are not very good, give people the opportunity. Myself...

Database security Policy Database security issues have been around the database administrator's nightmare, the loss of database data and the database by illegal user intrusion makes the database administrator physically and mentally exhausted. This paper puts forward some security policies around the security of the database, hoping to help the database administrator, no longer nightmares every night. Database security issues should include two parts: first, the security of database data it should be able to ensure that when the database system downtime, when the database data storage media is corrupted and when the database user misoperation, database data ...

It is well known that cloud OS Windows Azure and Cloud Database SQL Azure play a very important architectural role in Microsoft's cloud computing strategy. Among them, Windows Azure mainly includes three parts, one is the computing service of Operation application, the other is data storage service, the third is the controller (Fabric Controller) that manages and allocates resources dynamically based on cloud platform. And the database plays an important role in the entire Microsoft cloud strategy, especially for cloud database SQL Azure. In other words, SQ ...

It is well known that cloud OS Windows Azure and Cloud Database SQL Azure play a very important architectural role in Microsoft's cloud computing strategy. Among them, Windows Azure mainly includes three parts, one is the computing service of Operation application, the other is data storage service, the third is the controller (Fabric Controller) that manages and allocates resources dynamically based on cloud platform. And the database plays an important role in the entire Microsoft cloud strategy, especially for cloud database SQL Azure. In other words, SQL ...

Orient DB is a scalable document database that supports ACID transaction processing. Implemented using Java 5. Orientdb is an Open-source NoSQL database management system, written in Java, a document-type database that supports acid tx,http://www.aliyun.com/zixun/aggregation/16666.html "> Indexes,asynch queries,sql Layer ...

Logminer is an actual, useful analysis tool that Oracle has provided since 8i, which makes it easy to obtain specific content in Oracle Redo log files (archived log files), Logminer analysis tools are actually made up of a set of PL SQL package and a number of dynamic views that can be used to analyze online logs and archive logs to obtain a database of past detailed, specific operations, very useful. Why do you use Logminer? Mainly for the following reasons: When the database has been mistakenly operated, need not be completed ...

Http://www.aliyun.com/zixun/aggregation/13713.html ">hbase is a distributed, column-oriented open source database, rooted in a Google paper BigTable: A distributed storage system of structured data. HBase is an open-source implementation of Google BigTable, using Hadoop HDFs as its file storage system, using Hadoop mapreduce to handle ...

The following article is mainly about the specific method of implementing a simple and practical optimization of the MySQL database, as well as what specific steps in the actual operation are worthy of our attention. The following article describes the MySQL database is a simple practical optimization of the specific methods to achieve, including how to conduct regular table analysis and inspection, and how to properly optimize the table on a regular basis, the following is a description of the specific program, I hope in your future Learning will be helpful. 1, regular analysis table and checklist analysis table syntax is as follows: ANAL ...

Orientdb 1.0RC3 This version of the improved Manager index also uses multiple query criteria. Fixed mode is a refreshing problem. Many of the errors are distributed cluster configurations. The SQL ALTER Custer command has been added. Added SQL operator exists. In Graphdb, SQL GREMLIN () is added to the GREMLIN script to execute the SQL query result set, GREMLIN integration as a command execution script. General disk space allocation and performance improvements. A total of 34 questions were amended. ...