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Recent questions tagged sql

3 votes
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423
Navathe-Fundamentals of Database systems-basic SQL-sixth edition-4.8
Write appropriate SQL DDL statements for declaring the LIBRARY relational database schema of figure below. Specify the keys and referential triggered actions.
Write appropriate SQL DDL statements for declaring the LIBRARY relational database schema of figure below. Specify the keys and referential triggered actions.
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1 answer
424
Navathe-Fundamentals of Database systems-basic SQL-sixth edition-4.2
List the data types that are allowed for SQL attributes.
List the data types that are allowed for SQL attributes.
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4 answers
425
What will COUNT(*) returns if all the collection has only null values?
What will COUNT(*) returns if all the collection has only null values???
What will COUNT(*) returns if all the collection has only null values???
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56 votes
1 answer
426
GATE CSE 2016 Set 2 | Question: 52
Consider the following database table named water_schemes: ... total_avg (capacity) as select avg (capacity) from total select name from total, total_avg where total.capacity ≥ total_avg.capacity
Consider the following database table named water_schemes:$$\overset{\text{Water_schemes}}{\begin{array}{|c|c|c|}\hline\textbf{scheme_no}& \textbf{district_name}& \te...
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1 votes
1 answer
428
SQL
Can Foreign key value can be null??
Can Foreign key value can be null??
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1 votes
2 answers
429
MadeEasy Test Series: Databases - Sql
Can you please provide an elaborate explanation?
Can you please provide an elaborate explanation?
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1 votes
2 answers
430
General Topic Revision Databases: Sql
Name the SQL aggregation operator which does not ignore NULL. COUNT MAX AVG SUM
Name the SQL aggregation operator which does not ignore NULL. COUNTMAXAVGSUM
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2 votes
2 answers
432
sql query
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436
Can you please explain the second query
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438
Question on calculating the number of tuples in result of a database query
I couldn't understand its solution. Please explain
I couldn't understand its solution. Please explain
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0 votes
1 answer
439
Null values while aggrigate function in query
How aggrigate functions in query will behave in data contains NULL values. I think answer should be D as all aggrigatre functions EXCEPT count will ignore NULL values. so, AVG will be 300 and count will be 4
How aggrigate functions in query will behave in data contains NULL values.I think answer should be D as all aggrigatre functions EXCEPT count will ignore NULL values. so,...
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2 answers
440
Having clause
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442
Sql
In sql, these all are right or wrong Exist{}=true Not exist{}=true All{}=true Not all{}=true Any{}=false Not any{}=false In{}=false Not in{}=false
In sql, these all are right or wrongExist{}=trueNot exist{}=trueAll{}=trueNot all{}=trueAny{}=falseNot any{}=falseIn{}=falseNot in{}=false
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3 votes
2 answers
443
Output of given sql query
Use the following tables for the below queries wherever table $1$ and table $2$ are used: Select * From Table 1 Where not exists (Select $T_{2}B$ From Table 2 where $T_{2}B < > T_{1}B$) How many number of rows will be there in the output ? $1$ $2$ $3$ $0$
Use the following tables for the below queries wherever table $1$ and table $2$ are used:Select *From Table 1Where not exists (Select $T_{2}B$ From Table 2 where $T_{2}B ...
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2 answers
444
Question on SQL like operator
Given answer: D Please explain
Given answer: DPlease explain
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2 answers
445
Output of sql query with group by clause
A B C 5 2 1 10 NULL 2 15 2 3 In the above relation T the output of query: select * from T group by B; A B C 10 NULL 2 5 2 1 Can anyone explain why this is the output?
ABC52110NULL21523In the above relation T the output of query:select * from T group by B;ABC10NULL2521Can anyone explain why this is the output?
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0 votes
1 answer
446
Finding output of given SQL query
Given answer: B I don't know how to deal with NULL in such query operations. Please explain.
Given answer: BI don't know how to deal with NULL in such query operations. Please explain.
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0 votes
1 answer
447
Finding output of given SQL query
Given answer: B I don't know how to deal with NULL in such query operations. Please explain.
Given answer: BI don't know how to deal with NULL in such query operations. Please explain.
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1 votes
3 answers
448
MOCK_GATEFORUM_SAT6 SQL
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2 votes
2 answers
449
Sql group by clause?
How does group by works. ya it make groups of the data . and what i know it will group the data. what what i found on running on the online tutorials is that , the group by only shows me one entry for every distinct entry, can someone plz explain the way this group by works??
How does group by works. ya it make groups of the data . and what i know it will group the data. what what i found on running on the online tutorials is that , the group ...
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6 votes
4 answers
450
query
Consider the following instance $R$. A 1 2 3 4 B Null 1 2 2 The number of tuples returned by the following SQL query is > select * from $R$ as $R1$ where not exists (select * from $R$ where $B=R1.A$)
Consider the following instance $R$.A1234BNull122The number of tuples returned by the following SQL query is select * from $R$ as $R1$where not exists (select * from $R$...
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