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SEARCH KEYWORD -- Outer join

  An example of SQL outer join

SELECT MEMBER.Name, MEMBER.Address, ORGANIZER.phoneNo, TRAVEL.Tour_Name, TRAVEL.Start_Date, TRAVEL.End_Date FROM TRAVEL RIGHT JOIN ((MEMBER LEFT JOIN ORGANIZER ON MEMBER.Member_ID=ORGANIZER.memberID) LEFT JOIN PARTICIPATION ON MEMBER.Member_ID=PARTICIPATION.MemberID) ON TRAVEL.TravelID=PARTICIPATION.TravelID;...

   Access,SQL,Outer join     2011-03-20 09:08:11

  LEFT OUTER JOIN with ON condition or WHERE condition?

The difference is subtle, but it is a big difference. The ON condition stipulates which rows will be returned in the join, while the WHERE condition acts as a filter on the rows that actually were returned.Simple example: Consider a student table, consisting of one row per student, with student id and student name. In a second table, a list of grades that students have received, with student_id, subject, and grade. Give me a list of all students, and show their grade in Math. This requires a LEF...

   SQL,Outer jo0in,On,Where,On vs where,where vs on     2011-11-01 02:04:29

  Have Apple considered to develop iPad for aerospace use?

Today, I read article about China's Shenzhou 9 Spacecraft which is expected to be launched in middle of June. In this article, it mentions that the Chinese astronauts may bring some mobile devices with them in order for them to relax in such a long journey to outer space. The most probable devices they may bring are some tablets because laptops are too heavy to be placed in spacecraft which has limit space and weight capacity., while smartphones are too small and not so convenient for astronauts...

   Apple,iPad,Aerospace,Shenzhou 9     2012-06-14 05:41:20

  The magic of go:linkname

When writing Go program, there is frequent need on using time.Sleep() function to pause the logic for some time. And if jumping to the definition of this function, can see below definition: // Sleep pauses the current goroutine for at least the duration d. // A negative or zero duration causes Sleep to return immediately. func Sleep(d Duration) I's strange that there is no function body defined here. What happened? The actual definition of the function body is residing at runtime/time.go&nb...

   TRICKS,GO:LINKNAME,GOLANG     2022-04-10 08:39:00

  static nested and non-static nested class in Java

Nested classes are divided into two categories: static and non-static(inner). Nested classes that are declared static are simply called static nested classes. Non-static nested classes are called inner classes. Static class can be defined as : class OuterClass{ static class StaticNestedClass{ //OTHER STUFF } } Static nested classes are accessed using the enclosing class name: OuterClass.StaticNestedClass For example, to create an object for the static nested class, use this synta...

   Java,static nested class,inner class     2014-04-23 07:11:44

  JavaScript: Private variables

The first thing you often hear when talking about JavaScript is often “JavaScript doesn’t have visibility modifiers, hence it doesn’t support private variables”. This is only valid for 50%, because JavaScript indeed doesn’t have visibility modifiers (public, private, friend) but it has closures and function scopes. With these tools we can make variables private. Let’s take the following function: var names = ["Kenneth", "John", "Marc", "Robert"]; var lookup =...

   JavaScript,private variable,closure     2012-04-28 11:46:34

  Select top 3 values from each group in a table with SQL

Yesterday, my friend Liu Bing asked me a question about how to select top 3 values for each person in a database table using SQL. I think this question is interesting and it deserves some thoughts. Here I record down how to solve this issue. Assume we have a table which has two columns, one column contains the names of some people and the other column contains some values related to each person. One person can have more than one value. Each value has a numeric type. The question is we want to se...

   SQL,Correlated query,top 3     2013-05-23 03:21:25

  Understanding JavaScript closure and where it can be used

Closure The official definition of closure is: an expression (usually a function) that has many variables and is bound to an environment that includes those variables. In JavaScript, closure refers to the ability of a function to access the lexical scope in which it was defined, even after the function has been executed and left that scope. This ability is due to the fact that when a function is created, it generates a closure that includes a reference to the definition environment of the curr...

   CLOSURE,JAVASCRIPT,USAGE     2023-03-05 02:17:08

  Deep Understanding of ReentrantLock: Unlocking the Mysteries of Java Concurrent Programming

ReentrantLock introduction ReentrantLock is a class in the Java concurrent package, java.util.concurrent.locks, and is an implementation of the Lock interface. As its name suggests, it is a reentrant mutual exclusion lock. A mutual exclusion lock is a synchronization tool used to protect shared resources, ensuring that only one thread can access the resource at a given time. Reentrant means that a thread can acquire the same lock multiple times without causing a deadlock. This lock provides some...

   JAVA,REENTRANTLOCK,CONCURRENCY,MULTITHREADING     2023-05-22 08:01:13

  Motorola : A Google company

According to Sina Tech, Motorola Mobility has changed its company logo this week. The new logo comes with new graphic design and new font design. The new logo still has the 'M' badge and "MOTOROLA". However, the color of the 'M' badge changes from the old white to the new gray and the outer ring color also changes from red to multi-color. It is more like the Google logo's color scheme. At the same time, the "MOTOROLA" string on the logo also changes from upper case letters to lower case letters...

   Motorola Mobility,Logo,Google     2013-06-26 11:40:02

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