sql cookbook

Powerful SQL: SQL Cookbook Reading Notes 1-sorting the mixed data of letters and numbers recently, I am reading a really good book on SQL Cookbook. Many solutions are very subtle, I really realized that SQL is powerful. Note: I us

Label:The fifth Chapter Metadata query query database itself Information table structure index, etc.5.1 Querying all table information under the test libraryMysql from ' Test ';ORACLESelect from where ' Test ';5.2 Querying the information for columns in a tableMysqlSELECT * from WHERE = ' Test ' and = ' Student ';ORACLESelect * from where = ' Test ' and = ' Student ';5.3 List Indexes of tablesMysqlIndex from EMP;ORACLESelect from where = ' EMP ' and = ' Test ';5.4 Listing table constrain

1. Overlay of record setUse UNION ALLUnion all contains duplicate results, union filters out duplicates (may need to be sorted)1 Select * from where 5 2 Union All 3 Select * from where > 995\g2, the combination of related lines1 Select 2 from 3 where = and = and =ten\gThe above connection method is an equivalent connection, which is one of the inner joins.If you want the connection logic to be placed in the FROM clause, you can use the Join keyword1 Select 2fromjoinin=joinon= 3where=ten

Title: Web Cookbook Multiple SQL InjectionAuthor: Saadat Ullah, saadi_linux@rocketmail.com: Http://sourceforge.net/projects/webcookbook/Home: http://security-geeks.blogspot.com/Test System: Server: Apache/2.2.15 (Centos) PHP/5.3.3# SQL InjectionHttp: // localhost/cook/searchrecipe. php? Sstring = [SQLi]Http://www.bkjia.com/cook/showtext. php? Mode = [SQLi]Http: /

1. Traversing a stringThere is no iterative operation in SQL, so you can implement this process by connecting a table that is used as a traversal pointer.1 Selectsubstr (E.ename, Iter.pos,1) asC2 from(SelectEname fromEmpwhereEname= 'KING') E,3(SelectId asPos fromT10) ITER4 whereIter.posLength (e.ename);There are 10 data in T10, ID from 1-10.The FROM clause provides a Cartesian product, and the resulting table resemblesThe WHERE clause restric

Tags: data span Select partial structure ble let count ast1. Copy rows from one table to another 1 into dept_east (Deptno, Dname, loc) 2 Select deptno, dname, loc 3 from Dept 4 where inch ('New York'Boston') 2. Duplicate table structure Changing the Where condition can also copy part of the data 1 mysql>createtableas 2 Select* from film 3- where 1 = 0\g 3. Block insertions to a few columns Create a view that displays only the columns that the user is allowed to access 4. Delete al

First, retrieve data:1. Find rows that meet multiple criteria:SELECT*FromEmpWHEREDEPTNO = 10OR Comm is not NULLOR Sal and DEPTNO = 20;It returns all employees in the department 10 + all employees who receive a commission + 20 of employees with a salary not exceeding $2000.SELECT*FromEmpWHERE(Deptno = 10OR Comm is not NULLOR Sal )and DEPTNO = 20;It only returns to the eligible employees in Department 202. Refer to the alias column in the WHERE clause:SELECT*From(SELECTSal as salary,Comm As Commis

IntroductionSQL is a language in the computer world. When developing reports using relational databases, you need SQL knowledge to put data into databases and obtain data from databases. Many people use SQL in a careless manner and do not realize how powerful a weapon they possess. This book aims to open the reader's perspective and see what SQL can do to change

1, where clause, and priority is higher than or1 Select * from where Ten or like ' %ark ' and = \gis equivalent to the following query:1 Select * from where Ten or like ' %ark ' and = ) \g2. Connection column value: concat1 Select concat (" " as from Film\g3. Use Case statements1 Selecttitle,2 Case 3 whenLength - Then ' Short' 4 whenLength> - Then 'Long' 5 End 6 asInfo fromFilmwherefilm_id= 1\g4. Randomly select N data1 Select from Order by Rand 5\g5. Find empty values1

1. Write the program to list the required columns than direct write select * More intuitive. In this way, the performance of row data retrieval is the same, and the performance of column data retrieval is improved; When you select the required

IntroductionVue Cookbook vs. WizardsWhat is the difference between Vue's cookbook and the wizard? Why do you have to cookbook if you have a guide?1. A more exclusive explanation, in the wizard, we are actually telling a story, each part of the construction and presentation is derived from the previous module. But in cookbook