Question: Can we sort a column
using a column alias in SQL Server?
Answer: Yes, we can sort a
column using a column alias in SQL Server.
Example: Execute the following query
CREATE TABLE #TEMP
(
FNAME VARCHAR(100)
,LNAME VARCHAR(100)
,CREATEDDATE DATETIME,
)
INSERT INTO #TEMP
SELECT 'DILIP','SINGH',GETDATE()
UNION ALL
SELECT 'ANIL','SINGH',GETDATE()
UNION ALL
SELECT 'ASHISH','PRATAP', GETDATE()
-- In the following query, FNAME alias is FISRT_NAME. We can apply for Order by
clause on an alias as below
SELECT FNAME AS FIRST_NAME,LNAME AS LAST_NAME FROM #TEMP
ORDER BY FIRST_NAME ASC
DROP TABLE #TEMP
|
Question: What is the difference
between NULL value, zero, and blank space in SQL Server? Are these the same?
Answer: NULL value is the difference
from zero and blank space, a NULL value is unsigned, unavailable, unknown or not applicable
while zero is number, and blank space is the character.
Question: If a table contains
duplicates row, how can we eliminate from a query result?
Answer: We can eliminate duplicates
rows using DISTINCT keywords.
For
Example: Execute
following query.
CREATE TABLE #TEMP
(
FNAME VARCHAR(100)
,LNAME VARCHAR(100)
,CREATEDDATE DATETIME,
)
INSERT INTO #TEMP
SELECT 'DILIP','SINGH',GETDATE()
UNION ALL
SELECT 'DILIP','SINGH',GETDATE()
UNION ALL
SELECT 'ASHISH','PRATAP', GETDATE()
SELECT DISTINCT FNAME LNAME FROM #TEMP
DROP TABLE #TEMP
|
Question: What is default sorting ordering
of ORDER BY CLAUSE in SQL Server?
Answer: Default sorting order of ORDER By clause is ascending.
Question: Is the following query will
run or not in SQL Server?
SELECT FNAME LNAME, COUNT(*) FROM #TEMP
|
Answer: No, I will give an error '#TEMP.FNAME'
is invalid in the select list because it is not contained in either an
aggregate function or the GROUP BY clause.’
Right
query is.
SELECT FNAME LNAME, COUNT(*) FROM #TEMP
GROUP BY FNAME
|
