Oracle 10 Gb detailed analysis of common statements for table operations

There is a lot of information about Oracle 10g development on the Internet, because the actual database operations of enterprises in the past are generally based on Microsoft SQL2000 and 2005 versions. therefore, this period of time is also a conversion process. I ordered an Oracle Database 10 Gb SQL Master SQL and PL/SQL book online to repeat the complete system.

In general, I feel that I am actually reorganizing the Structured Query Language (Structured Query Language/SQL) SQL. despite repetitive work. but the experience is different. similar to this book, I have not paid much effort, but I feel like it is a thin line. associate all the fragments I have left before. the field of view is more open. I realized it slowly.

The work of program development can be rough and fine. we often feel the creative thinking made by a technical master (similar to Robert C. martin's agile practices) Actually, we don't know that they have been created in the gradual accumulation process. nothing is coming out of thin air. therefore, it is very important for a person born from technology to have a complete knowledge system structure. so I prefer a technician who was born in the cool class ..

The current situation is that fast food related to software development training has disrupted this pattern in the industry. We cannot control the pattern. whether this pattern is messy or not, but it is still the ability and consciousness of a technician to improve his or her knowledge system in actual work. we have inertia for the "External Force whip" of others' guidance. conscious consciousness can be truly powerful. this is not an overnight achievement.

It can be accumulated after a long period of time. only by constantly improving your knowledge system and learning continuously. it is a long-term development path for a real technician. this is also a very important standard for me to examine a technician.

This is also a problem that many programmers are most confused after getting started. The book mentioned above gives me some comments.

Oracle 10g SQL Master SQL and PL/SQL: I would like to recommend it to you. although the content is very simple, it gives me the feeling that the details are very comprehensive and can be used as a daily work manual query is no problem. on the one hand, it details and describes every detail of the SQL standard. at the same time, there are two chapters to explain in detail Oracle's own extension syntax. directly form a comparison. different from SQL standards in the future in a timely manner. it can be seen at a glance.

(A) SQL standard and Layer 3.

Let's look at the Structured Query Language (SQL for short) after "the future is born before. during this period, I was not reminded of the connection between the three-layer architecture of the underlying data access layer in my previous project. let's take a look at the SQL standard:

E. f. dr. Cold proposed the probability of a relational database. it sounds too new. but SQL is in E. f. dr. Cold's work has evolved from above. the first implementation was developed by IBM In The Middle Of 1970s. at that time, IBM launched a research project to become System R. SQL is born from this sort. by the end of 1979.

A company became Relational Software INc. company (in fact everyone should know that Oracle is now) released the first commercial version of SQL. with the development of SQL has been fully standardized. it is also certified by the American Standards Institute (ANSI. SQL can be used to access Oracle. SQL Server, DB2. and MySQL databases. till now.

Standardization of SQL Development. it also decouples the coding and database dependency for layer-3 division of labor. the programming language is not dependent on the database. this is mainly due to the standardization of SQL database access. currently, the mainstream data Oracle is set up. sqlServer DB2.MySQL each has its own set of database access rules. that's a terrible thing. when a database is switched, a data access layer is completely thrown away.

Then the encoding application is bound to the database. strictly speaking. any layer can be reused. display layer. the business logic layer and the data access layer are independent of each other when there is no actual dependency between the layers. if there is no SQL language standardization. therefore, there is no practical implementation of layer-3 division of labor. in the current project, if you implement the underlying database switch, you can make a simple factory mode by modifying the simple configuration. very low cost. if there is no SQL. all of this is impossible.

The above content is a detailed description of the frequently used statements for table operations in Oracle 10 GB and the description as you want. I hope it will help you in this regard.