oracle sql practice exercises

Recently downloaded a set of Oracle database exercises (no answer), I practice the answer on Oracle, if the wrong place, please do not take it amiss. Save to the blog to facilitate their own later lookup. Related tables: /* Student table /CREATE TABLE Student ( Sno varchar2 () primary key not NULL, sname varch

where D.deptno=e.deptno and d.loc= ' CHICAGO ';: 8. Use the max () function to find out all the information about the richest people in Chicago: Sql> Select e.* from emp e,dept D where E.deptno=d.deptno and d.loc= ' CHICAGO ' and sal= (select Max (SAL) from EMP e,dept D where E.deptno=d.deptno and d.loc= ' CHICAGO '); --select Max (sal) from EMP e,dept D where E.deptno=d.deptno and d.loc= ' CHICAGO '); is to find out what the highest wages in Chicag

Tags: style blog http color os using IO ar dataIn the work often see someone using with AS, query very smooth, also very quickly, very curious, there is a lot of information on the Internet, read the Great God's article, also practice a bit.First of all, the two-bit great God article link, the introduction is very detailed: http://www.cnblogs.com/fygh/archive/2011/08/31/2160266.htmlAnother great God's article: http://www.cnblogs.com/CareySon/archive/2

Tags: oracle command line unlock login table1. On the premise that the environment variable is well configured, strike the command #>sqlplus2. Enter username/password Login Oracle #> default we use first, user name: Scott, password: Tiger login3.A. When you log in, you can only tap Sqlplus, enter your username/password at the prompt, or you can:#> Sqlplus/nolog#> Conn Scott/tigerB. If the Scott user is lock

Oracle-hr Table query command exercises (a complete list of select commands) switch to the oracle hr user to practice 1. query the names and salaries of employees whose salaries are greater than 12000. Select initcap (concat (last_name, first_name) "name", salary from employees where salary> 12000; 2. query the name an

Tags: sdn cti www. Programming last support pre strong BirtNew Ket Network online programming Website: Https://www.nowcoder.com/activity/oj (SQLite is used by default) Topic 1: Get the execution plan for select * FROM Employees Select * from Employees; Topic 2: Last_Name and first_name of all employees of the Employees table are stitched together as name, separated by a space CREATE TABLE' Employees ' (' emp_no ')int( One) not NULL, ' birth_date ' date not NULL, ' first_name 'varchar( -) not

Link to the comprehensive exercise for creating, updating, and querying Oracle notes (11): Oracle notes (1) Introduction to Oracle and installation of explain (2) SQLPlus command http://www.bkjia.com/database/201209/154051.html#oraclenotes (3) scott user's table structure partition (4) simple query, restricted query, data sorting http://www.bkjia.com/database/201

The following table is saved in a database with information about a student sports meeting:Athlete sporter (athlete ID: sporterid, athlete name, athlete gender sex, department)Project item (Project No. itemid, project name itemname, project competition location)Score grade (athlete id, Project id itemid, point mark) Use SQL statements to complete the following functions: 1. Create a table and add constraints on the corresponding fields;Define the prim

1. On the premise that the environment variable is well configured, strike the command #>sqlplus2. Enter username/password Login Oracle #> default we use first, user name: Scott, password: Tiger login3.A. When you log in, you can only tap Sqlplus, enter your username/password at the prompt, or you can:#> Sqlplus/nolog#> Conn Scott/tigerB. If the Scott user is locked, it needs to be unlocked:#> alter user Scott account unlock;C. Want to see the current

=stopiccount+1 where @bkID =sid endExecute INSERT statement: INSERT INTOBbsreply (rid,rtid,rsid,ruid,rtopic,rcontents) VALUES (' 6 ', ' 2 ', ' 1 ', ' 2 ', ' employment difficult ', ' unequal opportunity ')In the Bbsuser table, the number of users in the Upoint will be added 1, in the Bbstopic table 2nd main posts of the reply volume (Treplycount) will be 7, the Bbssession table in the volume of posts (Stopiccount) will become 1601.? Delete the thread, user points minus 20, the number of posts in

1.sql writing: (1) from table (2) Where Condition (3) Select column2.rownum line number (pseudo column)1.1rownum is always generated in the default order and does not change after sorting1.2rownum can only use Explanation: Oracle is a row database, always the first row begins, row by line increment; >,>= is against the principle.3. Temporary tables2.1 Manual creation: Create global temporary TABLE * * * * *

[Practice]: Synchronize SQL server data to mysql and SQL Server mysql in real time 1. Install and install mysqlconne 2. Configure mysqlconnector ODBC data Manager-> system DSN-> Add-> mysql ODBC 5.3 ANSI driver-> Fill in the data source name, such as jt, mysql ip address, user name, and password. 3. Create a linked server Exec sp_addmediaserver@ Server = 'jt ', -

---------------------------------------------------- ------ 1 208 INACTIVE 2825768 25-apr-16 2 209 INACTIVE 2825872 25-apr-16 3 210 Current 2845771 25-apr-16 Join the current Log group Sql> EXECUTE DBMS_LOGMNR. Add_logfile (LogFileName = '/home/oracle/oradata/orcl/redo03.log ', O

Reprinted from the Heaven of stealingMotivation:You want to do insert/update directly with an SQL statement in Oracle.DescriptionWhen writing SQL statements, we often encounter a large number of simultaneous insert/update statements, that is, when there is a record, it is updated (update), when no data exists, insert (insert).Actual combat:Next we have a task, there is a table T, there are two fields, a, B,

Label:This article has been redirected from an excessive number of Oracle Dblink connections (Ora-02020)Today, when dealing with data synchronization issues, it is necessary to synchronize data from several other DB servers to a single target repository, in the following way: Dblink+job, however, Ora-02020 errors occur during the write process compilation. As follows: Environment: Target server (alias: DB) Other servers that need to be synchronized (

Super SQL Injection tool supports automatic identification of SQL injection and automatic configuration, such as the program does not automatically recognize, but also manual intervention to identify injection, and mark the injection location.The Super SQL Injection tool supports SQL injection anywhere in the HTTP pro

[Java project practice] dom4j parses xml files, connects to the Oracle database, and dom4joracleIntroduction Dom4j is an open source XML parsing package produced by dom4j.org. This sentence is too official. Let's take a look at the official explanation. For example: Dom4j is an easy-to-use, open-source library for parsing XML, XPath, XSLT, and other languages. It is applied to the Java platform and adopt

Io is very relevant, when the free buffer waiting in the v$session_wait of the entry is very small or not, Explain the DBWR process of your system will be enough, do not need to adjust, there are many items of free buffer wait, your system must feel very slow, then your DBWR is not enough, the resulting wio has become your database performance bottlenecks, the solution is as follows: A.1 to increase the write process while adjusting the db_block_lru_latches parameters Example: Modify or add the

string. For example:Sql> Select InStr (' abcdefgh ', ' de ') position from dual;POSITION----------4Starting from 1, the D row is the four, so return 4.Sql>select InStr (' Abcdefghbc ', ' BC ', 3) position from dual;POSITION----------9The 3rd character starting from the 3rd character is C, so find the BC after the 3 string, return 9---------------------------Starting with the 1th character, find the location of the 2nd occurrence of a substringSql> Se

recently in the study of SQL Server, the teacher laid out some small exercises. To tell the truth, these exercises can find the answer on the Internet, but what is the meaning of direct copy of the answer? It's a waste of life! The following attached to the original question and the individual SQL statements, such as t