gamification theory

Back to "flash Basic Theory Class-Catalog" Drawing curves using Curveto Next drawing function, Curveto (x1, y1, x2, y2), starting from the same point as the LineTo, is the same as the end of the drawing line as the starting point for this line, you can also use the MoveTo command to specify the beginning of the brush, if the first line draw the default starting point for 0, 0. As you can see, the Curveto function includes two points. The first is t

Back to "flash Basic Theory Class-Catalog" Animation events We want to be able to use code to make things move and allow the screen to refresh repeatedly. I've seen an example of using the Enterframe movie event earlier. Now apply this method to as 3, just add a listener to the Enterframe event: addEventListener(Event.ENTER_FRAME, onEnterFrame); Don't forget to import the Event class and create a method named Onenterframe. People often confuse, on

figure: This is because Baidu search results are used to match the reverse participle! 3, positive and negative to the same time participle matching And there is a special situation, is the combination of key words before and after the content is considered to be small, and the search results roll also contains the two groups of words, Baidu will be the positive and negative to the simultaneous segmentation matching, such as search key words: Beijing Hua Smoke, returned the results a

AutoIncrement counterUsage:delete from students; Delete all data from the students table, but the Automatically growing field data is not deletedTRUNCATE Students Delete Students table and its auto-growing field dataIv. UPDATEFormat: UPDATE tb_name SET col1=...,col2= ... WHERE ...V. LOCK LOCK StatementFormat: Lock tables Tb_name read|write; Locks the Tb_name table, the level is read lock, indicates can readWrite lock, which indicates that the table can be read and written but not deletedUnlock

SQL theory Questions1. What does a trigger do? A: A trigger is a special stored procedure that is executed primarily by triggering an event. It can enforce constraints to maintain the integrity and consistency of data, and can track operations within the database without permitting unauthorized updates and changes. Can be associated with a level operation. For example, a trigger on a table contains data operations on another table, and that action ca

Back to "flash Basic Theory Class-Catalog" Class and object oriented programming Classes (Class) and object-oriented (object oriented), for some readers may not have been contacted and some readers may have been used in as (or other languages) for many years, so that everyone can learn, I will briefly introduce these basics. Even OOP experts like 2 want to skim this section, because the working principle of as 3.0 does make a big difference. If you

XOR equation The positive integers A and B have a sum of s and a bitwise XOR of x. How many possible values is there for the ordered pair (a, b)? Input The first line of the input contains integers s and x (2≤s≤1012, 0≤x≤1012), the sum and bitwise XOR of the PAI R of positive integers, respectively. Output Print A single integer, the number of solutions to the given conditions. If no solutions exist, print 0. Examples input Copy 9 5 Output 4 Input Copy 3 3 Output 2 Input Copy 5 2 Output 0 Note I

Tags: options range tempdb modify base other records blog sortSQL Server default 4 system databases:1.master DatabaseRecords all system-level information for an instance of SQL Server, including instance-scoped metadata, endpoints, linked servers, and system configuration settings.2.TEMPDB DatabaseStaging database for saving temporary objects or intermediate result sets3.model DatabaseServes as a template for all databases created on the instance of SQL Server. Modifications to the model databas

expressionThe default is for all COLUMNS SIZE AUTO. Examplesan extension can be either acolumn Group(See Example1)orAn expression (see Example2). Example1Dbms_stats. Gather_table_stats ('SH','SALES', method_opt= 'for COLUMNS (empno, Deptno)'); Example2Dbms_stats. Gather_table_stats ('SH','SALES', method_opt= 'For COLUMNS (Sal+comm)'); Example3Dbms_stats. Gather_table_stats ('SH','SALES', method_opt= 'For COLUMNS sal size 1'Note: 1 represents the number of 1 buckets, that is, do not do a

again after a decentralized operation, which is time consuming. And if your Shard key is reflected in the search criteria, then even if you need to find a few shard scattered, because MONGOs has a direct, will know where to find, the effect will be much better. So to select a Shard key for collection, first determine which items will be used frequently in the search, find the most effective dependencies in these operations, such as a project may not be the kind of good identification can not be

Tags: one ISP manages. NET Mys func share pictures fast imaI. Database life cycle The database life cycle flowchart is as follows: Ii. drawings of each stage 　　 Fig. 1.1 Streaming chart Fig. 1.2 Data dictionary-Way 1 Additional notes: The data dictionary can be represented in a single table or in multiple tables (data Item table/structure table/Data flow table/external entity table, etc.) Fig. 1.2 Data dictionary-Way 2 Drawings 1.3 ER diagram-mode 1 Drawings 1.3 er diagram-mode 2 T

. main attribute:　　　　 The candidate main attribute is called the main attribute (primary attribute). 　　　　Non-primary attribute/non-code attribute : A property that is not contained in any candidate code, called a non-primary attribute . 　　　　full code : All the attributes in the relational schema form the candidate code for this relational pattern, which is called a full-size attribute group . 　　　　 "Precautions" Code/Candidate code/main code/full code: whenever the word "code" is involved, it

Database is divided into relational database and non-relational database;relational database: MySQL, oracle,sqlserver,db2,sybase,informix,access, etc. non-relational database: MongoDBRelational database: relational database stores data in rows and columns, which is easy to understand, it is based on relational model, and the relational model consists of three parts: relational data structure, relational operation set and relationship integrity constraint.Advantages:1. Maintaining data consistenc

a course, each class is taught by multiple teachers, and each student has multiple courses selected * *Understanding candidate codes (Student, Teacher, Course)Because of Teacher→course, but teacher is not a candidate code.4NFDefine RThe decision attribute (group) that understands all non-trivial multivalued dependencies must contain the candidate codeAnti-case WSC (Warehouse, Saver, commodity)/* warehouse, custodian, goods */Understand Warehouse→→saver, but Warehouse is not candidate codeGraphi

file organization: A record can be placed anywhere in the file:Sequential file organization: stored according to the "Search Code" value order:Hash file organization:Table structure definition file: Table data fileTablespace: Table SpaceData dictionary: Date dictonaryMetadata for relationshipsThe name of the relationshipField nameType and length of the fieldViewConstraintsUser password, authorization, passwordBuffer ManagerCache substitution PolicyThe block being peggedThis article from "Operat

-destructive connection. R1∩r2={c}, Calculate C+={c}. C is neither R1 nor R2, but it cannot be judged that the decomposition does not have a non-destructive decomposition, because this method of judgment is sufficient condition. We use the theorem to judge:U1∩u2={c}, whose closure is {C}U1-u2={abe}U2-U1={D}Therefore, u1∩u2→u1-u2€f+ and u1∩u2→u2-u1€f+ are not established, that is, do not have a non-destructive connectivity.Again judge to remain dependent:B→a,a→e,ac→b on the R1, d→a in the R1 and

mistake is to wear a separate multi-tone for each column, or create a multicolumn index in the wrong order. ”When it comes to indexing strategies, many of the vague suggestions such as "index the columns in the where" are very wrong. The best thing about this approach is only the "one Star" index,To achieve a truly better index, you need to optimize the order of indexed columns, or create a fully-covered index.---Note: The evaluation of indexes is mentioned in the third edition of "High Perform

to and which column corresponds to which property. The goal of the persistence layer is to accomplish the transformation of the object data and the relational data.2. Business layer: Complete processing of data obtained from the presentation layer, and related business operationsThe physical script pattern is used to encapsulate all operations in the current business into a single method that ensures that the operations succeed or fail simultaneously. Partial successes or partial failures are n

is no process hierarchy concept, all processes are of the same status, and the only hint similar to the process level is that when the process is created, the parent process gets a special token ( called a handle) that can be used to control the child process, But the parent process has the right to pass the handle to the other child processes, so there is no hierarchy.viii. Status of the processTail-f access.log |grep ' 404 'Execute the program tail, open a subprocess, execute the program grep

Regret Theory, also known as Regret Theory (Regret Theory) Four major research achievements in finance: Regret Theory, Prospect Theory, overreaction theory, and over-confidence theory )