teradata sql book

Recently learned SQL in Teradata environment. Here to record the study of the knowledge points, as a record.Directory: About SQL learning and the online database used Table Union (join) SQL Sub-query Create a new field at select (as, Case time) Data Grouping (group BY + aggregate function count

c.t_id=d.t_id left joins student A on a.s_id=b.s_id where D.tname= ' Zhang San '; /*dense_rank () */select E.s_id,e.c_id,e.score from (select s_id, c_id, Score,dense_rank () over (partition by c_id ORDER BY s_id) Rank1 from SC) e left joins course C on e.c_id=c.c_id left joins teacher D on c.t_id=d.t_id where D.tname= ' Zhang San ' and e.rank1=1; Select Top 1* from (select s_id, c_id, Score,dense_rank () up (partition by c_id ORDER by s_id) Rank1 from SC E left J Oin course C on e.c_id=c

Tags: implementation mechanism originally page organizes tables based on free article content index ClustFollowing the book on SQL tuning (SQL tuning or SQL optimization) in the essentials of high-performance SQL tuning and case resolution, we talk today about one of the mos

filegroup. Their backup order (a, C, B, a) reflects the business requirements of the database.Under the full recovery model, restoring a filegroup backup requires not only restoring the filegroup backup itself, but also restoring all log backups from the last full database backup to the target point in time of recovery. To ensure that the file remains consistent with the rest of the database. So the number of transaction log backups to recover will be large. To avoid this scenario, consider usi

. Start a page restore from a full database backup, file backup, or filegroup backup that contains the page. In the Restore DATABASE statement, use a page clause to list the page IDs of all the pages that you want to restore.Page= ' Filepage '3. Apply the most recent differential backup.4, apply the subsequent log backup.5. Create a new database tail-log backup.6, restore the new tail day backup. After you apply this new log backup, the page restore is complete and you can start to access the pa

"annual Salary"From EMP ORDER by 3 DESC;SELECT ename,job,sal from emp ORDER by Job,sal DESC;SELECT ename,job,sal from emp ORDER by Empno;Modify Default display widthSET line[size] {80|n}SET Line 100L display the SQL statement in the buffer you just enteredN Text modified section of error'/' (run) commandSAVEGET@ or Start command when the specified script file contents are loaded into the SQL buffer to runS

actions are automatically run if the free space is greater than 25%,sql server. So this feature prevents the data from requesting too much space and not using it. For a system with a very tight disk space, this setting is undoubtedly helpful. But from the database's own health and performance considerations, this setting is not recommended for multiple use. This is because:1. SQL Server will grow automatic

Original: SQL Server Enterprise Platform Management Practice book notes-backup and recovery of several system librariesmaster databaseMaster acts as the primary database for the database, documenting all system-level information for the SQL Server system, such as logged-on users, System configuration settings, endpoints and credentials, and the information needed

included with SQL ServerDatabase Not supported The resource database is located in the Mssqlsystemresource.mdf file,The file contains nearly the code. Therefore, SQL Server cannot back up the resource database.However, it can be done through file backup and backup to disk, and not through SQL Server when restoring.To restore these backups, you ca

I found a This book starts with some of the most basic knowledge and works with easy-to-understand examples to help you get started with simple knowledge points at and then go deeper step by step, each step will be used in concert with the example to explain to you. One small step at a time is the foundation of the next step, until the usage is relatively advanced. Oracle10g PL/SQL programming tutorial

the data object Partition_number Partition code Rows Approximate number of rows of data hobt_id Storage unit ID of the heap or B-tree where the data is stored Let's find a database to look at the fragmentation situation:You can see that the arrows refer to this row of data, the theory should be a zone on it, but in fact it establishes two partitions ... So this situation can be considered to defragment, to rebuild, to release deb

Multiple SQL injection and cross-site scripting vulnerabilities in PHP Address Book Release date:Updated on: Affected Systems:PHP Address BookDescription:Bugtraq id: 71862 PHP Address Book is a Web-based Address Book. PHP Address Book has multiple

Label:First, preface:As a fresh graduate and ready to interview the net Siege Lion, before in the library that this book is very basic, this time to go home to buy their own to review, by the way to do reading notes.Second, the code download:Official: http://forta.com/books/0672336073/　　Click I download SQL Server version from the Web diskThree, sample table:The table used in this

Tags: array rar organization Throw exception build log job schedule exec expressionThis week's book is the Ultimate guide to Oracle's C PL (SQL) programming, published by the mechanical industry press, Sun Fingdong, Wang Yu, Guo Xiaohui. Content Introduction: The ultimate guide to Oracle 12c PL/SQL is the most systematic, comprehensive, practical and

is no data returned to go in. Here is what we often say the universal password, the same can be directly run Sqlmap. So direct universal Password login backstage, the database is lazy run, login succeeded. The system is in the background and there is no data to speak of. As the preface says, there is almost always an injection of SQL statements where there is no filtering. Not a list of them. 0X02 Emergency Update Today again to the official websi

? method is to use the DISTINCT keywordSELECT DISTINCT vend_id from Products -- Analysis: SELECT DISTINCT vend_id tells the DBMS to return only (unique) vend_id rows. If you use the DISTINCT keyword, you must precede the column name directly. 　　Note The DISTINCT keyword is used for all columns, except that the two columns are exactly the same, and all rows are retrieved2.6 Limiting resultsThe SELECT statement returns all matching rows in the specified table. What if we just want to return

Myself. NET Novice, the beginner three layer will want to record to write notes, for like oneself the new person to study, the great God does not have to seeDAL layer:Determine if the encoding existspublic bool Exit (string strdrainno,string strid){StringBuilder strSQL = new StringBuilder ();{Strsql.append ("Select S1 from table WHERE drainno= '" + Strdrainno + "'");if (!string. IsNullOrEmpty (Strid)){Strsql.append ("and id!=" + Strid + "");}}DataTable dt = new DataTable ();DT = this. GetList (S

feature is set, SQL Server checks file usage every half hour. DBCC SHRINKFILE actions are automatically run if the free space is greater than 25%,sql server. So this feature prevents the data from requesting too much space and not using it. For a system with a very tight disk space, this setting is undoubtedly helpful. But from the database's own health and performance considerations, this setting is not r

Original: SQL Server Enterprise Platform Management Practice book Notes--sql Server database file allocation method1, file allocation methods and file space Check methodThe most common commands for checking data files and table sizes are: sp_spaceusedThis command has three defects: 1, the use of each data file and log file is not visible. 2, this stored procedure

are most appropriate for the database business requirements. This figure shows 4 filegroups, one at a time, for each filegroup. Their backup order (a, C, B, a) reflects the business requirements of the database.Under the full recovery model, restoring a filegroup backup requires not only restoring the filegroup backup itself, but also restoring all log backups from the last full database backup to the target point in time of recovery. To ensure that the file remains consistent with the rest of