C If Statement Multiple Conditions Example

1, use the index to traverse the table faster. The index created by default is a non-clustered index, but sometimes it is not optimal. Under non-clustered indexes, the data is physically stored on the data page. Reasonable index design should be based on the analysis and prediction of various inquiries. In general: a. There are a large number of duplicate values, and often range query (>, <,> =, <=) and order by, group by occurred columns, consider the establishment of cluster index; Column, and each column contains duplicate values ​​can be ...

1, use the index to traverse the table faster. The index created by default is a non-clustered index, but sometimes it is not optimal. Under non-clustered indexes, the data is physically stored on the data page. Reasonable index design should be based on the analysis and prediction of various inquiries. In general: a. A large number of duplicate values, and often range query (>, <,> =, <=) and order by, group by occurred column, consider the establishment of cluster index; b. Column, ...

Some tests are being done lately, with partial support for a smooth beta of the product. The following is the test of the Desktop. The first part: Windows programming UI design 1. Background introduction UI is the user interface (user-interface), is the interface between people and tools. In the process of human-machine interaction, it must be through the interface. This interface is actually reflected in every aspect of our lives, for example, when we drive the steering wheel and dashboard is this interface, watching TV when the remote control and the screen is this interface, the keyboard when using the computer ...

Intermediary transaction SEO diagnose Taobao guest Cloud host technology Lobby database optimization is a very complex task, because it ultimately requires a good understanding of system optimization. 　　Even though the system or application system does not know much about the optimization effect is good, but if you want to optimize the effect of better, then you need to know more about it. 1, the optimization of the system to run faster the most important factor is the basic design of the database. 　　And you have to be aware of what your system is going to do, and the bottlenecks that exist. The most common system bottlenecks are as follows: ...

In the past, we have introduced some principles of software development, such as the 10 commandments of high quality code and the UNIX design principles described in the UNIX legend (next article). I believe that you can learn from middle school some knowledge of design principles, as I said in the "How Do I Recruit procedures", a good programmer usually consists of its operational skills, knowledge level, experience level and ability four aspects. Here I would like to talk about some of the principles of design, I think these things belong to the long-term experience summed up knowledge. These principles should be understood by every programmer. But...

We want to do not only write SQL, but also to do a good performance of the SQL, the following for the author to learn, extract, and summarized part of the information to share with you! (1) Select the most efficient table name order (valid only in the Rule-based optimizer): The ORACLE parser processes the table names in the FROM clause in Right-to-left order, and the last table in the FROM clause (the underlying table driving tables) is processed first, In the case where multiple tables are included in the FROM clause, you must select the table with the least number of records as the underlying table. If...

Absrtact: At the beginning of 2015, there was a tearing war in the field of online education, and both sides of the war were Baidu and Couba June. First, Couba June accused Baidu in its multiple application distribution channels under the Couba June, the purpose is to support their own project work help. Again, at the beginning of the 百2015 years, the field of online education has taken place a tear force war, both sides of the war are Baidu and Couba June. First, Couba June accused Baidu in its multiple application distribution channels under the Couba June, the purpose is to support their own project work help. Again, Baidu through the update Baidu Encyclopedia "Couba June" entry to make official return ...

Absrtact: At the beginning of 2015, there was a tearing war in the field of online education, and both sides of the war were Baidu and Couba June. First, Couba June accused Baidu in its multiple application distribution channels under the Couba June, the purpose is to support their own project work help. Again, at the beginning of the 百2015 years, the field of online education has taken place a tear force war, both sides of the war are Baidu and Couba June. First, Couba June accused Baidu in its multiple application distribution channels under the Couba June, the purpose is to support their own project work help. Again, Baidu through the update Baidu Encyclopedia "Couba June" entry to do ...

Introduction: Research and development typically use a typical scenario (scenarios) to understand what a system needs and how the system works. Unfortunately, while research and development have done so, he rarely archives in an effective form. The use case (use-cases) is a formal, formalized technique for capturing these scenarios. The use case is Jacobson in the software engineering of the image object, but he is actually independent of the surface object. Use cases are an effective way to gain business process and system requirements. And the technology itself is very simple and easy to learn. Make the demand accessible ...

The intermediary transaction SEO diagnoses Taobao guest stationmaster buys cloud host technology Hall 1. When you display the data you want to select, you must first ask whether the data is massive. For example: Select the Drop-down box and add 100 records. Your users don't scold you.       2. Try not to limit user input. Validate input (regular expression) &n ...