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 following query
CREATETABLE#TEMP ( FNAMEVARCHAR(100) ,LNAMEVARCHAR(100) ,CREATEDDATEDATETIME, ) INSERTINTO#TEMP SELECT'DILIP','SINGH',GETDATE() UNIONALL SELECT'ANIL','SINGH',GETDATE() UNIONALL SELECT'ASHISH','PRATAP',GETDATE() -- In following query FNAME alias is FISRT_NAME. We can apply Order by caluse on alias as below SELECTFNAMEASFIRST_NAME,LNAMEASLAST_NAMEFROM#TEMP ORDERBYFIRST_NAMEASC DROPTABLE#TEMP |
Question: What is difference between NULL value, zero and blank space in SQL Server? Is they are same?
Answer: NULL value is difference from zero and blank space, NULL value is unsigned, unavailable, unknown or not applicable while zero is number and blank space is character.
Question: If a table contains duplicates rows how can we eliminate from query result?
Answer: We can eliminate duplicates rows using DISTINCT keywords.
For Example: Execute following query.
CREATETABLE#TEMP ( FNAMEVARCHAR(100) ,LNAMEVARCHAR(100) ,CREATEDDATEDATETIME, ) INSERTINTO#TEMP SELECT'DILIP','SINGH',GETDATE() UNIONALL SELECT'DILIP','SINGH',GETDATE() UNIONALL SELECT'ASHISH','PRATAP',GETDATE() SELECTDISTINCTFNAMELNAMEFROM#TEMP DROPTABLE#TEMP |
Question: What is default sorting ordering of ORDER BY CLAUSE in SQL Server?
Answer: Default sorting order ofORDER By clause is ascending.
Question: Is following query will run or not in SQL Server?
SELECTFNAMELNAME,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.
SELECTFNAMELNAME,COUNT(*)FROM#TEMP GROUPBYFNAME |