Consider this view: PDF (US Ltr) - 37.5Mb PDF (A4) - 37.5Mb PDF (RPM) - 36.9Mb HTML Download (TGZ) - 10.2Mb HTML Download (Zip) - 10.2Mb HTML Download (RPM) - 8.9Mb Man Pages (TGZ) - 211.3Kb Man Pages (Zip) - 321.0Kb Info (Gzip) - 3.4Mb Info (Zip) - 3.4Mb My SQL Backup and Recovery My SQL Globalization My SQL Information Schema My SQL Installation Guide My SQL and Linux/Unix My SQL and OS X My SQL Partitioning My SQL Performance Schema My SQL Replication Using the My SQL Yum Repository My SQL Restrictions and Limitations Security in My SQL My SQL and Solaris Building My SQL from Source Starting and Stopping My SQL My SQL Tutorial My SQL and Windows My SQL NDB Cluster 7.5 One of the limitations above is that you cannot have duplicate column names.
create table Employee( 2 ID VARCHAR2(4 BYTE) NOT NULL, 3 First_Name VARCHAR2(10 BYTE), 4 Last_Name VARCHAR2(10 BYTE), 5 Start_Date DATE, 6 End_Date DATE, 7 Salary Number(8,2), 8 City VARCHAR2(10 BYTE), 9 Description VARCHAR2(15 BYTE) 10 ) 11 / Table created.
select e.empno,e.ename,e.sal,e.deptno,d.dname,From emp e, dept d where e.deptno=d.deptno; So everytime we want to see emp details and department names where they are working we have to give a long join query.
Instead of giving this join query again and again, we can create a view on these table by using a CREATE VIEW command given below create view emp_det as select e.empno, e.ename,e.sal,e.deptno,d.dname,from emp e, dept d where e.deptno=d.deptno; Now to see the employee details and department names we don’t have to give a join query, we can just type the following simple query.
To be more specific, a view is not updatable if it contains any of the following: .
For information about generated columns, see Section 188.8.131.52, “CREATE TABLE and Generated Columns”.
It is sometimes possible for a multiple-table view to be updatable, assuming that it can be processed with the value for a view has become inaccurate to due to changes to underlying views, the value can be updated by deleting and recreating the view.
The connection to the DBMS is terminated and all data in the library becomes unavailable.
proc sql; title 'Current Population Information for Continents'; create view sql.newcontinents as select continent, sum(population) as totpop format=comma15.
label='Total Population', sum(area) as totarea format=comma15. label='Total Area' from sql.countries group by continent; select * from sql.newcontinents; Current Population Information for Continents Total Continent Population Total Area --------------------------------------------------------------------- 384,772 876,800 Africa 710,529,592 11,299,595 Asia 3,381,858,879 12,198,325 Australia 18,255,944 2,966,200 Central America and Caribbean 66,815,930 291,463 Europe 813,335,288 9,167,084 North America 384,801,818 8,393,092 Oceania 5,342,368 129,600 South America 317,568,801 6,885,418 In this example, each column has a name.
Does it mean delete all employees that are in department LCR?
Does it mean set to null the dept_code for employees in department LCR?