How you will avoid duplicating records in a query?

How you will avoid duplicating records in a query?
by

1 Answer

Answer :

By using DISTINCT
by

Related questions

A query fetched 10 records How many times does a PRE- QUERY Trigger and POST-QUERY Trigger will get executed ?

Description : A query fetched 10 records How many times does a PRE-QUERY Trigger and POST-QUERY Trigger will get executed ?

Last Answer : PRE-QUERY fires once. POST-QUERY fires 10 times.

How you will avoid your query from using indexes?

Description : How you will avoid your query from using indexes?

Last Answer : SELECT * FROM emp Where emp_no+' '=12345; i.e you have to concatenate the column name with space within codes in the where condition. SELECT /*+ FULL(a) */ ename, emp_no from emp where emp_no=1234; i.e using HINTS

How will you delete duplicating rows from a base table?

Description : How will you delete duplicating rows from a base table?

Last Answer : delete from table_name where rowid not in (select max(rowid) from table group by duplicate_values_field_name); or delete duplicate_values_field_name dv from table_name ta where rowid

If the maximum record retrieved property of the query is set to 10 then a summary value will be calculated?

Description : If the maximum record retrieved property of the query is set to 10 then a summary value will be calculated?

Last Answer : Only for 10 records.

What is a Query Record Group?

Description : What is a Query Record Group?

Last Answer : A query record group is a record group that has an associated SELECT statement. The columns in a query record group derive their default names, data types, had lengths from the database columns ... rows retrieved by the query associated with that record group. What is a Non Query Record Group?

What is the Difference between a post query and a pre query

Description : What is the Difference between a post query and a pre query

Last Answer : A post query will fire for every row that is fetched but the pre query will fire only once.

Suppose a customer table is having different columns like customer no, payments.What will be the query to select top three max payments?

Description : Suppose a customer table is having different columns like customer no, payments.What will be the query to select top three max payments?

Last Answer : SELECT customer_no, payments from customer C1 WHERE 3

What is correlated sub-query ?

Description : What is correlated sub-query ?

Last Answer : Correlated sub query is a sub query which has reference to the main query.

There is a % sign in one field of a column. What will be the query to find it?

Description : There is a % sign in one field of a column. What will be the query to find it?

Last Answer : '' Should be used before '%'.

My query was fine last week and now it is slow. Why? (for DBA

Description : My query was fine last week and now it is slow. Why? (for DBA

Last Answer : The likely cause of this is because the execution plan has changed. Generate a current explain plan of the offending query and compare it to a previous one that was taken when the query was ... the plan should be? Run the query with hints to see if this produces the required performance.

When is PRE-QUERY trigger executed ?

Description : When is PRE-QUERY trigger executed ?

Last Answer : When Execute-query or count-query Package procedures are invoked.

Why query fails sometimes ?

Description : Why query fails sometimes ?

Last Answer : Rollback segment dynamically extent to handle larger transactions entry loads. A single transaction may wipeout all available free space in the Rollback Segment Tablespace. This prevents other user using Rollback segments.

Where is the external query executed at the client or the server?

Description : Where is the external query executed at the client or the server?

Last Answer : At the server.

How is it possible to select generate a select set for the query in the query property sheet?

Description : How is it possible to select generate a select set for the query in the query property sheet?

Last Answer : By using the tables/columns button and then specifying the table and the column names.

What is a difference between pre-select and pre-query?

Description : What is a difference between pre-select and pre-query?

Last Answer : Fires during the execute query and count query processing after oracle forms constructs the select statement to be issued, but before the statement is actually issued. The pre-query trigger fires ... the query criteria in enter query mode.Pre-query trigger fires before pre-select trigger.

Is it possible to modify an external query in a report which contains it?

Description : Is it possible to modify an external query in a report which contains it?

Last Answer : No.

If a parameter is used in a query without being previously defined, what diff. exist betw. report 2.0 and 2.5 when the query is applied?

Description : If a parameter is used in a query without being previously defined, what diff. exist betw. report 2.0 and 2.5 when the query is applied?

Last Answer : While both reports 2.0 and 2.5 create the parameter, report 2.5 gives a message that a bind parameter has been created.

What is a query?

Description : What is a query?

Last Answer : A query with respect to DBMS relates to user commands that are used to interact with a data base. The query language can be classified into data definition language and data manipulation language.

What is meant by query optimization?

Description : What is meant by query optimization?

Last Answer : The phase that identifies an efficient execution plan for evaluating a query that has the least estimated cost is referred to as query optimization.

What is Query evaluation engine?

Description : What is Query evaluation engine?

Last Answer : It executes low-level instruction generated by compiler.

Display Odd/ Even number of records?

Description : Display Odd/ Even number of records?

Last Answer : Odd number of records: select * from emp where (rowid,1) in (select rowid, mod(rownum,2) from emp); Output:- 1 3 5 Even number of records: select * from emp where (rowid,0) in (select rowid, mod(rownum,2) from emp) Output:- 2 4 6

Display the records between two range?

Description : Display the records between two range?

Last Answer : select rownum, empno, ename from emp where rowid in (select rowid from emp where rownum

What is ORA-01555 - Snapshot Too Old error and how do you avoid it?

Description : What is ORA-01555 - Snapshot Too Old error and how do you avoid it?

Last Answer : The ORA-01555 is caused by Oracle read consistency mechanism. If you have a long running SQL that starts at 11:30 AM, Oracle ensures that all rows are as they appeared at 11:30 AM, ... -01555 snapshot too old also relates to your setting for automatic undo retention ▪ Don't fetch between commits

What is ORA-01555 - Snapshot Too Old error and how do you avoid it?

Description : What is ORA-01555 - Snapshot Too Old error and how do you avoid it?

Last Answer : The ORA-01555 is caused by Oracle read consistency mechanism. If you have a long running SQL that starts at 11:30 AM, Oracle ensures that all rows are as they appeared at 11:30 AM, ... -01555 snapshot too old also relates to your setting for automatic undo retention ▪ Don't fetch between commits

……….. can decrease the space on hard disks by duplicating files. -Technology

Description : ……….. can decrease the space on hard disks by duplicating files. -Technology

Last Answer : Virusescan decrease the space on hard disks by duplicating files.

Assertion: Coacervates are believed to be precursors of life. Reason: Coacervates were self duplicating aggregates of proteins surrounded by lipid mol

Description : Assertion: Coacervates are believed to be precursors of life. Reason: Coacervates were self duplicating aggregates of proteins surrounded by lipid mol

Last Answer : Assertion: Coacervates are believed to be precursors of life. Reason: Coacervates were self duplicating ... both the assertion and reason are false.

Should he focus on duplicating his successful offline marketing efforts to an online audienceTRUE?

Description : Should he focus on duplicating his successful offline marketing efforts to an online audienceTRUE?

Last Answer : 1

If He charges 17.95 for each CD and his expenses include 1250 for duplicating equipment and 0.65 for each blank CD which equation shows the profit (p) for selling n CD's?

Description : If He charges 17.95 for each CD and his expenses include 1250 for duplicating equipment and 0.65 for each blank CD which equation shows the profit (p) for selling n CD's?

Last Answer : What is the answer ?

EPROM can be used for A) Erasing the contents of ROM B) Reconstructing the contents of ROM C) Erasing and reconstructing the contents of ROM D) Duplicating ROM

Description : EPROM can be used for A) Erasing the contents of ROM B) Reconstructing the contents of ROM C) Erasing and reconstructing the contents of ROM D) Duplicating ROM

Last Answer : Answer : C

Which of the following is not a way of acquiring software? a) Buying pre-written software b) Ordering customized software c) Downloading public-domain Software d) Duplicating the software

Description : Which of the following is not a way of acquiring software? a) Buying pre-written software b) Ordering customized software c) Downloading public-domain Software d) Duplicating the software

Last Answer : Answer: d Explanation: Duplication is not a correct way of acquiring the software. All the other options are valid. Apart from these, another option could be development of a customized software

In an office, Franking machine is used for– (A) Punching card (B) Accounting work (C) Duplicating (D) Postal stamp fixing

Description : In an office, Franking machine is used for– (A) Punching card (B) Accounting work (C) Duplicating (D) Postal stamp fixing

Last Answer : Answer: Postal stamp fixing

EPROM can be used for --- 1) Erasing the contents of ROM 2) Reconstructing the contents of ROM 3) Erasing and reconstructing the contents of ROM 4) Duplicating ROM

Description : EPROM can be used for --- 1) Erasing the contents of ROM 2) Reconstructing the contents of ROM 3) Erasing and reconstructing the contents of ROM 4) Duplicating ROM

Last Answer : 3) Erasing and reconstructing the contents of ROM

In planning and construction of a cast metal partial denture the study cast, M07 A. facilitate the construction of custom/special trays B. minimize the need for articulating C. provide only limited information about inter ridge distance, which is best assessed clinically D. can be used as a working cast when duplicating facilities are not available

Description : In planning and construction of a cast metal partial denture the study cast, M07 A. facilitate the construction of custom/special trays B. minimize the need for articulating C. provide only ... best assessed clinically D. can be used as a working cast when duplicating facilities are not available

Last Answer : A. facilitate the construction of custom/special trays

Which of the following statements is FALSE about weak entity set ? (A) Weak entities can be deleted automatically when their strong entity is deleted. (B) Weak entity set avoids the data duplication and consequent possible inconsistencies caused by duplicating the key of the strong entity. (C) A weak entity set has no primary keys unless attributes of the strong entity set on which it depends are included. (D) Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

Description : Which of the following statements is FALSE about weak entity set ? (A) Weak entities can be deleted automatically when their strong entity is deleted. (B) Weak entity set avoids the data ... weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

Last Answer : (D) Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set.

How can a search engine know exactly what you want to look for before completely finishing the query?

Description : How can a search engine know exactly what you want to look for before completely finishing the query?

Last Answer : Based on what other people that typed the same ended up clicking on when they went to the page of results.

FB query: I have timeline review on but things are still being shared on my timeline?

Description : FB query: I have timeline review on but things are still being shared on my timeline?

Last Answer : answer:I wish I knew because sometimes people post things on my timeline and I see other friends have liked them, which shows me that people can see them before I approve them. Other things ... can be so confusing sometimes with privacy settings and things like that, I wish they made it simpler.

Another website design query (Details...)

Description : Another website design query (Details...)

Last Answer : answer:I would recommend looking in to writing scripts using jQuery. I'm currently in the process of designing a site myself and have been amazed at what can be accomplished now with just a ... here. They range from very simple beginner guides to some advanced shit that will rearrange your brain.

How can there be "1000 search results per query?" no matter what the query is?

Description : How can there be "1000 search results per query?" no matter what the query is?

Last Answer : answer:If you can find more than a few dozen relevant results, you are very fortunate. By posting the 1,000 most relevant results for a search, you can give the person either more detail than they ... random stuff. In the former case, 1,000 results is enough, in the latter, search is unnecessary.

What is better: One big SQL query or several?

Description : What is better: One big SQL query or several?

Last Answer : It’s difficult without examples. But what you describe seems like a simple join.

Query about different blood types?

Description : Query about different blood types?

Last Answer : The “negative” is RH. A negative is RH negative also.

Antibiotic query ... about reactions?

Description : Antibiotic query ... about reactions?

Last Answer : i dont blame you…penicillin almost killed me once. anaphalaxis. I rarely take antibiotics now. Just be aware.

How to get the value from a listbox populated by a query in access 2007?

Description : How to get the value from a listbox populated by a query in access 2007?

Last Answer : Can the code be placed in the form with the list boxes? Then you could refer to them without the qualifiers, like this id_proyecto.Value id_muestra.Value

Blisters in the corners of my mouth/lips and dentists...query?

Description : Blisters in the corners of my mouth/lips and dentists...query?

Last Answer : When I’ve gotten impressions or dental work that has taken a while I’ve gotten REALLY mild blisters the next day or so….yours seem a lot worse, but I would assume they’ll go away…

Data source to query for a list of stocks?

Description : Data source to query for a list of stocks?

Last Answer : You might want to check out Google’s Finance API.

How can I use the Twitter Search API to return all tweets that match my search query, posted only within the last five seconds?

Description : How can I use the Twitter Search API to return all tweets that match my search query, posted only within the last five seconds?

Last Answer : Nevermind, I don’t see a way to do this. I have a different method to fall back on, but this would have been ideal.

HD TV Tuner card query...

Description : HD TV Tuner card query...

Last Answer : answer:

What's the most important thing to know for sending a query letter to a journal, magazine, or newspaper?

Description : What's the most important thing to know for sending a query letter to a journal, magazine, or newspaper?

Last Answer : When sending a query letter, use it as an opportunity for the editor to sample the style of the piece you're querying. In other words, match the tone of your letter to the tone of the story/article. ... adress the query to that editor. In this day and age, there's no reason this should be missing.

Is there something wrong with my MySQL query?

Description : Is there something wrong with my MySQL query?

Last Answer : answer:SELECT CONCAT_WS( ’ ’, first_name, last_name ) AS full_name, username, country, region, CONCAT_WS( ’, ’, region, country ) AS location FROM people HAVING full_name[equal]‘John Doe’ Damn! I’ve been awake for a long time. Silly me.

Define query in the context of database. -Technology

Description : Define query in the context of database. -Technology

Last Answer : A query is an inquiry into the database using the SELECT statement. These statements give you filtered data according to your conditions and specifications indicating the fields, records, and summaries which a user wants to fetch from a database.

Data is stored in RDBMS in the form of (a) table (b) query -Technology

Description : Data is stored in RDBMS in the form of (a) table (b) query -Technology

Last Answer : (a) Relational Database Management System stores data in the form of relation. As we know, relations are known as table.