Oracle

Write a simple query statement1. Display all the information of the Department tableSelect * FROM Dept;2. Show department number, department nameSelectdeptno,dname from Dept;3. Displays the following fields and string connections: Employee name, "1

[Turn]http://www.cnblogs.com/linjiqin/archive/2012/01/16/2323320.htmlFirst, when establishing the table, pay attention to the role of pctfree parametersPCTFREE: The percentage of space reserved for a block, indicating when the data block can be

Job: Flash Back Table experiment1. Construct the test table flb_test, the data is not less than 10000 lines;[email protected]>create table flb_test (ID number,dd date);Table created.[email protected]>begin2 for I in 1..100003 loop4 INSERT into

(Study record)In the Code table class and field class please refer to: http://meijia.blog.51cto.com/8684191/1563874The relevant parameters can be adjusted by reference to the API.(Same note format)1. The method is as followsPublic list Export ()

1.student classPackage Com.test.hou.po;public class Student {private int sid;private String sname;private int sage;public int GetSID () {R Eturn SID;} public void Setsid (int sid) {this.sid = SID;} Public String Getsname () {return sname;} public

Because Oracle has a slightly different format for adding and deleting columns, it is hereby documented for easy viewing later.1. Add Columns:Sql> ALTER TABLE t1 add y integer;Table AlteredExecuted in 0.046 secondsDescription: Added column format

Hot and then we'll clean up. Use of a keyword about the database (Oracle)Union keywordUnion literally means "union", which allows you to combine two SQL statements together to query for the desired query results.As an example,The following tables

1. Support App Interface call2. New tall H5 interface, beautiful and stylish3. There are Oracle and MySQL versions of each4. The framework is well built, and many projects have been done on this basis5. Basic functions have been

So long finally can calm down to tidy up the work to learn the things (mainly or oneself too lazy. ）Say less nonsense, the text beginsIn the company, the basic database is Oracle, so learn a bit of Oracle's knowledge, now to sort out their own

When deleting data with delete, the SQL statement first finds the qualifying record and deletes it through a full table scan or an index scan. In this process, however, a lot of CPU resources, I/O resources, and undo data will be consumed. If you

Oracle scheduled task and oracle task I. IntroductionWhen we need the oracle database to automatically execute some scripts, or perform database backup, database performance optimization, including re-indexing, etc., we need to use the scheduled

Plsql_performance optimization series 13_Oracle Index Rebuild Index reconstruction, plsql13_oracle 2014-10-04 BaoXinjian I. Summary Index rebuilding is a topic that is constantly under discussion. Of course, Oracle also has its own opinions. Many

Single-row functions of oracle reinforcement exercises 1. dname AND loc are separated- Select dname | '-' | loc From dept; 2. Fill the team name with 10 digits left Select lpad (dname, 10) From dept; 3. Replace the employee's name' Select replace

The ORA-00600 [kollasg: client-sidetmplob] Today, when I checked the log of a library, I found the screen was flushed by the ORA-00600 [kollasg: client-side tmp lob] error. The cause of this error is the lob problem on the application side. Lob is

PL/SQL -- package, plsql -- I. Package A package is a combination of PL/SQL programming elements such as related processes, functions, constants, variables, cursors, and exceptions. It is similar to classes in C ++ and Java, where variables are

Adjust the size of redologfile in oracleracAdjust the size of the redo log file under rac(1) view the current log information:Select * from v $ logfile;(The path in step 2 can be seen in the MEMBER column here. The redo file name is named by

Oracle Performance Analysis 11: system statistics The overhead calculation of the early Oracle query optimizer was based on the physical reads required to execute SQL statements. This method is called the I/O overhead mode (I/O cost model ), the

PL/SQL -- triggers and plsql triggers I. IntroductionThe trigger is stored as an independent object in the database. Unlike the stored procedure and function, the stored procedure and function must be displayed and called before execution, A trigger

2. On the oracle tab, find the employees whose salaries are higher than the average salaries of the Department. ROWNUM knowledge point A rownum is generated according to the default oracle mechanism. B rownum can only use = Rownum Implementation

Oracle row-to-column and column-to-rowI. Row-to-column ConversionThe following format must be set:Convert:This is the most common row-to-column conversion. The main principle is to use the decode function, aggregate function (sum), and group by