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Between Operator for Date Fields
What is the disadvantage of using "BETWEEN" for date feilds
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Access data from Database
In which manner the SQL commands access the data from database?
chandu77
- Mar 17th, 2008
Accessing data from a database depends on its implementation.consider the follwing statement select empname from emp where empid=100;(Oracle)1:first the server process of oracle checks wheth...
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Types of Databases
How many types of databases are there? What are they?
akavitha
- Feb 28th, 2008
These days when we talk abt database we are mainly talking about 2 databases namely : Analytical DatabaseOperational DatabaseAnalytical Database : Like OLTP( On Line Analytical Processing) are p...
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What is the difference between ROWNUM and ROWID
sampra
- Feb 26th, 2008
the ROWNUM is a number(like serial no) which is dynamically changes.but the ROWID does not change.Because it is having the unique address,which is generated by the oracle
g_sidhu
- Feb 7th, 2008
Rowid: Hexadecimal string representing the unique address of a row in its table. This datatype is primarily for values returned by the ROWID pseudocolumn. Rownum: For each row returned by ...
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How to see the existing constraints in a table?
safdar
- Feb 14th, 2008
HI I AM SAFDAR DOGAR create table dept1( deptno number(10) constraints pk_deptno primary key, dname varchar2(20), loc varchar2(20 ));desc user_constraints;select constraint_name,constraint_type from user_constraints where table_name='DEPT1';AM I RIGHT
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What is the Difference between stored procedures and external procedures?
sampra
- Feb 26th, 2008
An external procedure is simply a program unit that is not written in Oracle’s SQL or PL/SQL and resides outside of the database. External procedures must be stored as shared libraries at the op...
g_sidhu1
- Feb 21st, 2008
An external procedure is simply a program unit that is not written in Oracle’s SQL or PL/SQL and resides outside of the database. External procedures must be stored as shared libraries at the operating system level. In a Windows NT environment, the procedure would be compiled into a DLL.
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There is a table with Pluks(‘plk’) and Zinks (‘zin’). Each Pluk onlyresides on a single Zink and each Zink may contain multiple Pluks. Howdo you find how many Pluks are on each and every Zink? Please provide SQL.
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What is the difference between SQL standard joins and Oracle propreitary joins
g_sidhu
- Feb 13th, 2008
The Oracle9i database offers join syntax that is SQL: 1999 Compliant. Prior to release 9i, the join syntax was different from the ANSI standards. The new SQL: 1999 Compliant join syntax does not offer any performance benefits over the Oracle proprietary join syntax that existed in prior releases.
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What is the data type of the column of Dual table?
g_sidhu
- Feb 13th, 2008
The DUAL table is owned by the user SYS and can be accessed by all users. It contains one column, DUMMY, and one row with the value X. The DUAL table is useful when you want to return a value once onl...
kowmudiswarna
- Sep 13th, 2007
Hi,The data type of column of dual table is character data type i.e varchar2
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Datareader Dataset
How to fill Dataset from Datareader?
Venkat
- Feb 12th, 2008
by using datasetds = new dataset()sqlDbAdapter ad = new sqlDbAdapter(sqlquery,connobject)ad.fill(ds,tablename)DataReaderdr = new sqlDataReader()sqlCommand sqlcmd = new sqlcommand(sqlqry,conObject)dr =...
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How do i get Greatest salaray of dept group from emp and dept?we have to tables EMP and DEPT. for exp: dept 10 have 10000,dept 20 have 5000 and dept 30 have 15000 salaries, i need dept 30 group salary(means sum of that group is 15000).
vipsforever
- Feb 9th, 2008
Select department_id, m.salary from employees m where m.salary =(select max(salary) from employees where salary in( select max(salary) from employees group by department_id));
bharadh
- Oct 22nd, 2007
Select deptno,sum(sal) from emp where depno in(select deptno from emp where sal)=(select max(sal) from emp group by deptno)
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In Oracle10g sqlplus, how do you find the tables that have been dropped?
g_sidhu
- Feb 7th, 2008
When you drop a table, normally the database does not immediately release the space associated with the table. Rather, the database renames the table and places it in a recycle bin, where it can later...
Suresh
- Aug 4th, 2006
You can use this command to retrieve the dropped table, simply by querying,FLASHBACK TABLE TO BEFORE DROP;you can also query this to view the objects that can be undropped,SHOW RECYCLEBIN
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What is an inline view?
g_sidhu
- Feb 7th, 2008
An inline view is created by placing a subquery in the FROM clause and giving that subquery an alias. The subquery defines a data source that can be referenced in the main query.
rampratap409
- Dec 12th, 2006
When a query is given inplace of tablename in from cluse . The query becomes a inline view.
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Explain psudo column Label with an example
g_sidhu
- Feb 7th, 2008
LEVELYou use LEVEL with the SELECT CONNECT BY statement to organize rows from a database table into a tree structure. LEVEL returns the level number of a node in a tree structure. The root is level 1, children of the root are level 2, grandchildren are level 3, and so on.
Tatyana
- May 5th, 2006
Sorry, sorry, I am wrong. Rowid is a pseudocolumn.
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What is the difference between single quote (') and double quote(") in relates to using in SQL. When do you use 'xxx' and "xxx"? what is the difference both of them?
g_sidhu
- Feb 7th, 2008
Date and character literals must be enclosed within single quotation marks (' ');If a column alias contains a space, it should be enclosed in double quotation marks.
rampratap409
- Dec 4th, 2006
double quote(") is used to give user defined column alias example:select empno , ename "employee name" from emp;this will print column heading as: EMPNO ...
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Difference between case expresssion and case statement
g_sidhu
- Feb 7th, 2008
The CASE statement supported by PL/SQL is very similar to the CASE expression. The main difference is that the statement is finished with an END CASE statement rather than just END. The PL/SQL statements are essentially an alternative to lists of IF .. THEN .. ELSIF statements:
oraappsexp
- Feb 9th, 2006
CASE Expressions And StatementsThe CASE expression was first added to SQL in Oracle8i. Oracle9i extends its support to PL/SQL to allow CASE to be used as an expression or statement:Value Match CASE Ex...
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What is an UTL_FILE.What are different procedures and functions associated with it?
UTL_FILE is a package that adds the ability to read and write to operating system files. Procedures associated with it are FCLOSE, FCLOSE_ALL and 5 procedures to output data to a file PUT, PUT_LINE, NEW_LINE, PUTF, FFLUSH.PUT, FFLUSH.PUT_LINE,FFLUSH.NEW_LINE. Functions associated with it are FOPEN, ISOPEN.
g_sidhu
- Feb 7th, 2008
With the Oracle-supplied UTL_FILE package, you can read from and write to operating system files. It Provides security for directories on the server through the init.ora file. UTL_FILE Procedures and ...
Rakesh
- Mar 20th, 2007
Utl_file is oracle procedure tht enable file access .You can write ,read to file.Also possible is to del or rename a file.It requires the use of a directory object.
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What is OCI. What are its uses?
Oracle Call Interface is a method of accesing database from a 3GL program. Uses--No precompiler is required,PL/SQL blocks are executed like other DML statements. The OCI library provides-functions to parse SQL statemets-bind input variables-bind output variables-execute statements-fetch the results
g_sidhu
- Feb 6th, 2008
The Oracle Call Interface (OCI) is a set of low-level APIs (Application Programming Interface Calls) used to interact with Oracle databases. It allows one to use operations like logon, execute, parse,...
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How you open and close a cursor variable.Why it is required?
OPEN cursor variable FOR SELECT...StatementCLOSE cursor variable In order to associate a cursor variable with a particular SELECT statement OPEN syntax is used. In order to free the resources used for the query CLOSE statement is used.
g_sidhu
- Feb 6th, 2008
• The OPEN-FOR statement associates a cursor variable with a multirow query, executes the query, identifies the result set, and positions the cursor to point to the first row of the result set.&b...
S.Senthil Kumar
- Oct 31st, 2006
Without Open Cursor statement the data which is in the table cannot be load into cursor variable.The Close Cursor statement deallocates the memory occupied by the cursor
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Difference between NO DATA FOUND and %NOTFOUND
NO DATA FOUND is an exception raised only for the SELECT....INTO statements when the where clause of the querydoes not match any rows. When the where clause of the explicit cursor does not match any rows the %NOTFOUND attribute is set to TRUE instead.
g_sidhu
- Feb 6th, 2008
NO DATA FOUND: Is an exception which is raised when no rows are retrieved from the database in a SELECT statement, then PL/SQL raises the exception NO_DATA_FOUND.%NOTFOUND: is a Boolean attribute that evaluates to TRUE if the most recent SQL statement does not affect any rows.
syam sundar
- Aug 17th, 2007
NO DATA FOUND is an exceptionWhen your?SELECT INTO?statement?returns no rows that time an error raised by oracle. The error is ORA-01403 NO DATA FOUNDWhereas %NOTFOUND?is a?cursor attributeIt ret...
Oracle SQL Interview Questions
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