Oracle

1. To enable Python to operate the Oracle database, you first need to install the Cx_oracle package, which can be obtained from the address below[Plain]View PlainCopy http://cx-oracle.sourceforge.net/ 2. Additional Oracle class

Database index processing is a bit of a problem, simply recordOracle rules that objects under the same schema cannot be named with the same name, typically creating index names with "table name _ Field name", so that you can quickly know which table

Logical storage of the database, starting from the table spaceThe logical storage structure for a database object is as followsTable Space-Segment-zone-BlockSELECT * from Dba_tablespaces;SELECT * FROM Dba_segmentswhere tablespace_name= ' Kyc_veh

This morning to the company, opened the computer and found that the launch of the Oracle instance, reported the following error:Oops, all of a sudden worried, the original still good how suddenly so? I recalled that it was my previous modified

I. ORACLE internal structure1. Table SpaceA tablespace is a logical division of a database, a table space belongs to only one database, each table space consists of one or more data files, and other logical structures in the table space are stored

In the common use of a database often encountered the problem of locking table, the phenomenon of occurrence.1. Stored procedures cannot be executed2, the query table data appears slowly3, the front end of the phenomenon of card deathThe data that

A) UsersUsers in Oracle are divided into two major categories1) when the Oracle database server is created, users that are automatically created by the system are called system users, such as Sys.2) users created by the system users, called ordinary

/************** Date ********************/1.select trunc (sysdate) from dual--2013-01-06 today's date is 2013-01-062.select trunc (sysdate, ' mm ') from dual--2013-01-01 returns the first day of the month.3.select trunc (sysdate, ' yy ') from dual--2

Create Oracle Tablespace and user/**/createtemporary'e:\tablespace\test_temp.dbf 'onnext 50m maxsize 20480mextent management local; /* 2nd step: Create a data table space */ create tablespace test_data Loggingdatafile " e:\tablespace\test_

This article transferred from: http://www.cnblogs.com/suding1188/archive/2013/01/06/2848067.htmlThe use of the--oracle trunc () function/************** Date ********************/1.select trunc (sysdate) from dual--2013-01-06 today's date is 2013-01-0

Select To_char (sysdate, ' Yyyy-mm-dd hh24:mi:ss ') from dual; --Show Current time2011-12-29 16:24:34Select Trunc (Sysdate, ' year ') from dual; -Interception to year (first day of this year)2011-1-1Select Trunc (sysdate, ' Q ') from dual;

--insert a record into the tableCreate or Replace procedurepro_insertdept isbegin Insert intoScott.deptValues(' the','Dog','Dog'); Commit; Endpro_insertdept;--Executionbeginpro_insertdept; End;--define three input parameters, insert a recordCreate

Updating a field is simple and easy to understand: Update TableA a set a.name= (select name from TableB B where a.id=b.id) is more verbose when updating multiple fields: Update TableA a set A.name= (select name from TableB b where a.id=b.id), a.age=

You can think of the result set of group by as a table, and then you can take the number from here.e.g.Select A.project_code,a.die_no,e.one_consuming from (select T.project_code, T.die_no, SUM (t.offline_qty) OffqtyFrom Data_plan TWHERE t.begin_date

Storage FunctionsCreate or replace function Name of function (name in type, name out type, ...) return Data Type is result variable data type ;begin return ( result variable );end[Name of function];The difference between stored procedures and

Many times we need to filter the table to update, INSERT, delete and other operations. So if we're going to be a lot of trouble with a single table, here's how the merge into usage will greatly optimize the time and amount of code for our operation

--1. Lists all department and department information for at least three employees.SELECT D.deptno, D.dname, D.loc, t.countsFrom DEPT D, (SELECT DEPTNO, COUNT (*) COUNTS from EMP GROUP by DEPTNO) TWHERE D.deptno = T.deptnoand T.counts >= 3;--2. List

--View data usage for all table spacesSELECT Upper(f.tablespace_name) "tablespace name", D.TOT_GROOTTE_MB "table space size (M)", D.TOT_GROOTTE_MB-f.total_bytes "used Space (M)", To_char (Round((D.TOT_GROOTTE_MB-F.total_bytes)/D.tot_grootte_mb* -,2)

Packages are used to logically combine procedures and functions, which consist of package specifications and package bodies.1), we can use the Create Package command for creating packages such as:I, create a package sp_packageII. Declare that the

To view the remaining table space:Select tablespace_name,sum(bytes)/1024x768/1024x768| | ' M ' from Group by Tablespace_nameView Total table space size, usage size, remaining size, usage, remaining