learning sql pdf

'Get Column NameSelect column_name from Information_schema.columns where table_name= ' table_name 'Get contentSelect ' column_name ' from Schema_name.table_nameSqlilabs 's Less-24 has experienced the next two injectionsRegister to create an account with admin ' # , password is 123you can make a change to the password, and when you change the password, two injections will occur, because # will update the query with the following commentcan see by changing the admin ' # user's password, the resul

. If it is a derived property, it is represented by a dashed ellipse. Contact (Relationship): With a diamond, the diamond box is indicated by the contact name, and the non-forward side is connected with the relevant entities, while in the non-edge side of the contact type (1:1, 1:n or m:n). In the case of a weak entity, the diamond is then set outside the diamond. The relationship between conceptual data model and E-R model The conceptual Data Model (conceptual) is also known a

Label: Create TableCustomers (Idint Identity(1000000,1), Companyvarchar( -)NULL, Namevarchar( -)NULL ) Insert intoCustomersValues('Fun4all','Tom') Insert intoCustomersValues('Alibaba','Tim') Insert intoCustomersValues('BaiDu','Jerry') Insert intoCustomersValues('G0ogle','Herry') Insert intoCustomersValues('Tencent','Mahuateng') Insert intoCustomersValues('Fun4all','Tom') This is the SQL script needed to explain 1. The self-junction code is as fo

\entitysix\EFLog\LogOutput.txt"/> "false"Type="System.Boolean"/> After running, you can view theOpened connection at the/9/ - -: +: the+ ,:xxSELECT ' Extent2 '. ' id ', ' Extent2 '. ' Code ', ' Extent2 '. ' Name ' from ' Prod_category_vs_prod ' as ' Extent1 ' INNER JOIN ' prod ' As ' Extent2 ' on ' Extent1 '. ' prod_category_id '=' Extent2 '. ' id ' WHERE ' Extent1 '. ' prod_id '=@EntityKeyValue1--EntityKeyValue1:'2'(Type = Int32, isnullable =false)--Executing at the/9/ - -: +: the+ ,:xx--Comp

remainder of two numbers. SelectFName, Fweight, fweight%5 fromT_person # -), natural logarithm: #MySQL中: #LOG (X) The function accepts a parameter. Also accepts a parameter of two numbers. #LOG (b,x) B is the integer entered for itself. X is the parameter to be asked. The logarithm of the bottom of the #MySQL支持以2为底, base 10, at any self-input. SelectFName, Fweight, LOG (fweight) fromT_personSelectFName, Fweight, LOG2 (fweight) fromT_personSelectFName, Fweight, LOG10 (fweight) fromT_personSelec

What is "anti-pattern"Anti-patterns are a way of trying to solve a problem, but they often cause other problems at the same time.Anti-Pattern classification(1) Logical Database design anti-patternBefore you begin coding, you need to decide what information is stored in the database and how best to organize and correlate the data.This includes tables, fields, and relationships for how to design a database.(2) Physical Database design anti-patternOnce you have identified what data you need to stor

What is "anti-pattern"Anti-patterns are a way of trying to solve a problem, but they often cause other problems at the same time.Anti-Pattern classification(1) Logical Database design anti-patternBefore you begin coding, you need to decide what information is stored in the database and how best to organize and correlate the data.This includes tables, fields, and relationships for how to design a database.(2) Physical Database design anti-patternOnce you have identified what data you need to stor

1 ImportPymysql as PS2 3 #Open a database connection4db = Ps.connect (host='localhost', user='Root', password='123456', database='Test', charset='UTF8')5 6 #Create a Cursor object7Cur =db.cursor ()8 9 #parametric processingTensql ="INSERT into USER (Name,password) VALUES (%s,%s)" One ACur.execute (SQL, ('Little Black','123456')) - - Print("OK") the - #Commit the transaction (this must be actively committed, otherwise in the database operation incre

, so it is not necessary to remove the duplicate rows and arbitrarily use DISTINCT, but should first understand whether the data used may contain duplicate rows, To reduce the need to use distinct.6. SQL if the string with wildcards still does not provide enough flexibility, you can use a regular expression.Find records with names beginning with F or GMysql:select * from EMP where name REGEXP ' ^[FG] 'Oracle uses regexp_like and

name set column name = expression [...,]WHERE ConditionExample:Update score set classid=1821 where classid=1823 Change 1823 to 1821(Can have logical representations of and and or )(4) Inquiry recordGrammar:Selcet column 1 [, column 2,...]From table nameWHERE ConditionGROUP BY grouping expressionsHaving group statistics conditionsOredr by sort expressionExample:Example 1: Querying the basic information of all studentsSelect * FROM StudentExample 2: Check the test scores of all students and

,getdate ()-birthFrom Is_studentwhere GETDATE ()-birth >20(5) A view with an expressionDefines a view of a student's year of birth, including number, name, and year of birthCreate View bt_s (Studentid,studentname,birth)AsSelect Studentid,studentname,getdate ()-birthFrom student(6) Views with grouped statistics:Define a view of each student's academic number and average scoreCreate View S_g (Studentid,grade)AsSelect Studentid,avg (Grade)From gradeGROUP BY StudentID2. Modify the View:Alter VIEW vi

>alter table Pet drop weight;  change column ALTER TABLE tbl_name modify Col_name type For example, change the types of weight: mysql> ALTER TABLE pet Modify weight SAMLL int Another method is: ALTER TABLE tbl_name change old_col_name col_name type For example: mysql> ALTER TABLE pet change weigh T weight samllint;  Renaming the column Mysql>alter table pet Change weight wei;  Rename table ALTER TABLE tbl_name rename NEW_TBL For example, rename the pet table to animal Mysql>al

Statement-aggregate Function-AVGPrivate voidTsmiavg_click (Objectsender, EventArgs e) { varStulist = Session. Queryover0). List (); DoubleAvgage = ( fromSinchStulistSelects.age). Average (); MessageBox.Show (Avgage.tostring ()); } #endregion #region5.3 Execute LINQ Statement-aggregate Function-SumPrivate voidTsmisum_click (Objectsender, EventArgs e) { varStulist = Session. Queryover0). List (); intSumage = ( fromSinchS

was designed without consideration and NBSP; IISNBSP; used together. However, a localdb database can be easily migrated to SQLNBSP;SERVERNBSP; or NBSP, sqlazure In Visual Studio(or ),Visual Studio installs the default LocalDB . By default, theEntity Framework looks for a database connection with the same name as the object context class (Moviedbcontext in this project ). Open the Web. config file for the application's root directory (not in the Views directory, web. config). F

[Database Study Notes] (3) ing between SQL data types and Java data types, learning notes Data Types Comparison of Data Types Between SQL database and access Database Text nvarchar (n)Note ntextNumber (long integer) intInteger smallintNumber (single precision) realNumber (Double Precision) floatNumber (byte) tinyintCurrency moneyDate smalldatetimeBooleanIng be

=11111111111111111"--dump--all dump dataSqlmap.py-u "Http://www.lingbook.com?test=lingbook"--cookie= "phpsessid=11111111111111111" data= "Data stitching string"--dbsSqlmap.py-u "Http://www.lingbook.com?test=lingbook"--cookie= "phpsessid=11111111111111111" data= "Data stitching string"--dbs-- Batch--smart Auto-select YesSqlmap.py-g "inurl:www.lingbook.com" Google search FQsqlmap.py--g "keywords"--batch--smart find injection pointsWeb firewall: Hardware firewall, software firewallDetermine if ther

Typical Cases of Database SQL learning: exercises for scores of professional students; for one question ------ which students have chosen course 1 but not course 2? The following SQL statements are written in different ways ~ No mysqldescSC; + ------- + --------------- + ------ + ----- + --------- + ------- + | Field | Type | Null Typical Cases of Database

, CompTIA is professional, fair and impartial in the field of information security talent certification. Security+ certification is highly operational and closely related to the daily work of frontline engineers. Suitable for banks, securities, insurance, internet companies and other IT-related personnel learning. As an international certification in 147 countries around the world are widely recognized.Under the current tide of information security, t

When you query a product on a product introduction website, because the introductory text of the product may be very long, if you use like for a fuzzy query of the product introduction field,Performance is definitely a problem. How can this problem be solved? The first idea is to use full-text indexes. So what is full-text index, how should it be applied, and what should be paid attention to during the application process? ThisPost is the note for learning