What is the focus of sql and what is the focus of SQL

1Understand what a relational database is.

2. Learn the three things about relational databases.

3. Database ER diagram.

If you learn the above, not only SQL Server can learn well, but all other databases can be learned well.

The focus of SQL is SQL statements, and it is beneficial to learn more.

1.View. 2.Index.

3.Cursor. 4.Function.

5.Stored procedures, triggers.

6.Affairs. 7.Lock.

Of course, other things are not important, such as some simple additions, deletions, modifications, and checks, these are the basics; The above list can be used as topics to gnaw off one by one.

create datebase database name.

create table table name Create a table.

select *from table name query statement.

insert into the table name (field) and values (value) to insert the statement.

update table name set field = value where condition to modify the statement.

delete from table name where condition delete statementThe above statement is the most commonly used especially multi-table query is difficult Even if I write a multi-table query statement, you can't understand it, so I won't write it Read more books is important.

The core of SQL language is retrieval, and it can be said that all the essence is in this retrieval. As for the deletion, addition, modification and other operations, they must be built on the foundation of the inspection and defeat of Nasuo.

Hope to check the slag spring.

Add (add) Delete (remove) Check (find) Change (modify) is mainly what we call adding records to the four major functions of adding, deleting, checking and modifying: insert into table (field) values('value'Delete a record: delete from the table where field='value'Find Records:

select from table where field='value'Change history: update table set field 1='value'where field2='value'

To solve this problem, we must first talk about "process-oriented programming languages", "object-oriented programming languages", and "structured query languages".

In fact, these three are completely different concepts. Let's take the example of the equation "1+1 2". "Process-oriented programming language" should be understood as the process of the entire equation from formation to completion, such as why 1+1 is equal to 2, and is there an answer to equal to 2?

Is there any other way than 1+1, like 0+2 or so on. To put it professionally, learning process-oriented is mainly to learn "algorithms" to improve computing efficiency; "Object-oriented programming language" should be understood as how to "visualize" the equation "1+1 2", that is, the equation is composed of five "objects": "1", "1", "and "2".

Speaking of professionalism, learning the image is mainly from how to apply the object to design the user interface; The understanding of "structured query language" is the most special, and it was very uncomfortable for me as someone who has learned from process orientation to object orientation at first. Because, it is solved by the process of the completion of the equation. You don't have to worry about how the equation is formed and calculated, you just want it to be a result.

As above, you can give the computer a command that says, I want the result to be equal to 2He will give you all the equations that the result is equal to 2. To sum up, all three languages have to be learned.

Process-oriented is to learn algorithms to improve efficiency, object-oriented is to learn the presentation of user interfaces, and structured queries are to facilitate data processing.

Not the same. C is a programming language. SQL is the database control language. Development software often embeds SQL into the C language. to control the database.

The default is. or a native IP or loopback address.

If there is an instance name.

It is the IP (machine name) instance name, if it is not the default port, you need to create an alias, add the port number to the alias, and the ODBC access is the IP (machine name) instance name and port number.

SQL Server 2008 is released on Microsoft's data platform and can organize and manage any data. Data for structured, semi-structured, and unstructured documents can be stored directly into the database. You can query, search, sync, report, and analyze your data.

Data can be stored on a variety of devices, from the largest servers in the data center all the way to desktops and mobile devices, and it can control the data regardless of where it is stored.

SQL Server 2008 allows the use of MicrosoftData is used in custom applications developed by .NET and Visual Studio, in service-oriented architecture (SOA) and in business processes through Microsoft Biztalk Server. Information workers can access data directly through the tools they use every day.

Running a query in the query analyzer can be understood as: query = retrieve data + display; There is no separate display.

If you call a query in the program, it is a result set that is returned, and you need to write ** for reshooting, pagination, and then display.

I don't know what you don't understand, can you elaborate more?

SQL programming, such as the triggers that have been deleted and modified, SQL stored procedures, transactions that often use SQL, etc., are to be mastered, and you need to understand that you need to use it in actual development, unless you use it when there is a lot of data, the latter is generally not used!

At the very least, you must be able to write SQL statements, in fact, as long as you are proficient in the addition, deletion, modification and search of SQL statements, the database is basically the same.