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Is it possible to create Synonym for Triggers ?
If your answer is yes, explain the steps.
gkbiswal
- Sep 29th, 2007
Yes we can.create or replace trigger trg_testbefore insert on empbeginnull;end;create synonym trg_syn for trg_test;
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How to know the size of the table we created?
Waseem Mehmood
- Nov 20th, 2007
SELECT BYTES/1024 FROM DBA_EXTENTS WHERE OWNER = 'SCOTT' AND SEGMENT_NAME = 'EMP'; This will return you size of table in Kilo Bytes. User is Scott and Table is Emp.
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What is Locking? Explain types of Locking? Explain example of Locking? What is database link? Explain types of database link? Explain example of database link?
vaibhav Tyagi
- Oct 21st, 2007
ROWLOCK Use row-level locks when reading or modifying data. PAGLOCK Use page-level locks when reading or modifying data. TABLOCK Use a table lock when reading or modifying data. DBLOCK Use a database...
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How SQL Statment is processed?
ritesh_ksingh
- Apr 21st, 2008
To process an SQL statement, a DBMS performs the following five steps: The DBMS first parses the SQL statement. It breaks the statement up into individual words, called tokens, makes sure that the sta...
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How to add a primary key to a table that is not having any primary key?How to display the Date of birth from a table in the dd-mm-yyyy format?
Waseem Mehmood
- Nov 20th, 2007
ALTER TABLE table_nameADD CONSTRAINT table_column_pk PRIMARY KEY (column_name);It is a table level primary key constraint applied on an existing table. SELECT TO_CHAR(DOB, 'DD-MM-YYYY') FROM table_name;
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How to insert of only system time(hh:mi:ss) into table columnnot in the format of 'dd/mm/yyy hh:mi:ss' only system time not date.
Waseem Mehmood
- Nov 20th, 2007
CREATE TABLE table_name(col1 VARCHAR2(20));INSERT INTO table_nameVALUES(TO_CHAR(SYSDATE, 'HH:MI:SS'))While creating table you must keep in mind the datatype must be Varchar2 for required column
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How to find the difference between two dates omitting weekends and holidays?
vanigreat
- Jan 17th, 2008
select (to_date('31/01/2008','dd/mm/rrrr')-to_date('01/01/2008','dd/mm/rrrr')+1) - (select count(days) from (selectto_char(to_date('01/01/2008','dd/mm/rrrr&...
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How to delete a constraint if it is not named?
kishore.giri
- Dec 10th, 2007
Dear Shruti,First query the data dictionary view "USER_CONS_COLUMNS" to find the constraint name.Then instead of dropping the constraint just disable it.step1:--> select constraint_name,c...
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How to drop a column level constraint?
I cant drop the whole column because that is interlinked with my process? I have declared not null on a column, I have to change it
kishore.giri
- Dec 10th, 2007
Dear Sarika,Instead dropping the constraint just disable the constarint.The command is:Alter table table_name disable constraint constraint_name;try it and reply me
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Index on coloumns
How to see on what coloumns the indexes have been created?
Waseem Mehmood
- Nov 29th, 2007
SELECT * FROM ALL_INDEXES WHERE TABLE_NAME = 'table_name'-- It will give u all indexes in required table
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Date functions
How to know the days or months or years between two employees in emp table.
jbabu
- Dec 10th, 2007
Select hiredate,lead(hiredate,1) over(order by hiredate) next_months, round(months_between(lead(hiredate,1) over(order by hiredate),hiredate),3) months from emp;
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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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What is SQL Tuning?
What is SQL Tuning? How does it work? Thanks
abhi2433
- Feb 6th, 2008
SQL tuning is the process of ensuring that the SQL statements that an application will issue will run in the fastest possible time
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Between Operator for Date Fields
What is the disadvantage of using "BETWEEN" for date feilds
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Security for SQL Queries?
Can you provide any security for SQL queries? If Yes, How?
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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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Print number of columns and column names
How to print the number of columns in a particular table also the column names without using JDBC Result set meta data using pure SQL code.
nareannl
- Oct 17th, 2008
Select count(column_name),column_name from user_tab_columns where table_name='tablename';
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Table and Column Level Locks
How to handle the table level locks and column level locks?
krishnaindia2007
- Jun 20th, 2008
When you are performing INSERT , DELETE , UPDATE operations on a table it implicity aquires row level locks. If a transaction obtains a row lock for a row, the transaction also aquires a table l...
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Lock Row of a Table using SQL
How to lock a particular row of a table using SQL?
krishnaindia2007
- Jun 20th, 2008
INSERT , UPDATE, DELETE operations implicity lock rows of a table that satisfies the condition.Explicitly you may lock a table using for update of as followsSELECT * FROM EMPWHERE EMPNO = 7369FOR UPDATE OF SAL NOWAITIt will lock single row of emp table having employee number 7369.
Oracle SQL Interview Questions
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