Sql Analyst Interview Questions
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Sql Analyst interview questions shared by candidates
SQL - Trigger, Stored Procedure, SQL Basics, truncate & delete HR - Joins, Multirow functions
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Trigger is a kind of special stored procedure which will execute automatically when a when an event occures in database server. Less
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Stored procedure is a prepared SQL code which is saved for reusing.
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Truncate is similar to the delete command but it removes entire table. Delete is the command Which is used to remove some data by using where clause. Less
If I knew what the cross apply operator was
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If they want the word its join, a description could be "the Cartesian product of multiplying the tables" and an example would be "like merging two matrices except every column may be of incongruent variables creating a result with polynomial rows, (which is likely no longer normalized to the form level of the database)" Less
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An Apply operator is a join type that the query engine evaluates in sequential order because the right-hand table object can reference data in the left-hand table object. The Cross Apply operator is the Apply operator that acts like an Inner Join, eliminating any records in the left-hand table object that have a null match in the right-hand table object. Less
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An Apply operator is a join type that the DB engine evaluates in sequential order because the right-hand table object can reference data in the left-hand table object. The Cross Apply operator is the Apply operator that acts like an Inner Join, eliminating any records in the left-hand table object that have a null match in the right-hand table object. Less
Given 2 dates, return a result set that outputs a number for each week between the two. (They will ask the numbered week to be the sequential week and also the calendar week. Prepare for given start date to be start mid-week.)
3 Answers↳
--Given 2 dates, return a result set that outputs a number for each week between the two. (They will ask the numbered week to be the sequential week and also the calendar week. Prepare for given start date to be start mid-week.) declare @temp date, @d date = '2020-01-01', @dd date = '2020-03-01', @i int = 0 declare @t table (w int, d date); declare @w int, @wp int = 0 set @temp = @d; while @temp @wp begin insert into @t values (@w, @temp) set @wp = @w end end select * from @t; Less
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--Given 2 dates, return a result set that outputs a number for each week between the two. (They will ask the numbered week to be the sequential week and also the calendar week. Prepare for given start date to be start mid-week.) declare @temp date, @d date = '2020-01-01', @dd date = '2020-03-01', @i int = 0 declare @t table (w int, d date); declare @w int, @wp int = 0 set @temp = @d; while @temp @wp begin insert into @t values (@w, @temp) set @wp = @w end end select * from @t; Less
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DECLARE @Start_Dt DATE = '2020-01-07', @End_Dt DATE = GETDATE(), @SequencialWeek_No INT = 1, @OldWeek_No INT = 0, @Week_No INT = 0; DROP TABLE IF EXISTS #Temp; CREATE TABLE #Temp ( Date DATE, Week_No INT, SequencialWeek_No INT ); WHILE @Start_Dt <= @End_Dt BEGIN SET @OldWeek_No = @Week_No; SET @Week_No = DATEPART(wk, @Start_Dt); SET @SequencialWeek_No = CASE WHEN @Start_Dt = '2020-01-07' THEN 1 WHEN @OldWeek_No = @Week_No THEN @SequencialWeek_No ELSE @SequencialWeek_No + 1 END; INSERT INTO #Temp ( Date, Week_No, SequencialWeek_No ) SELECT @Start_Dt, @Week_No, @SequencialWeek_No; SET @Start_Dt = DATEADD(DAY, 1, @Start_Dt); END; SELECT * FROM #Temp ORDER BY Date; Less
What is the result if we do following Null + 90
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Always remember null + anything will be null. Also applicable for - ,* ,/
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Null
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Null .anything+ null is null
Not unexpectedly, the manager was particularly interested in my experience in gathering requirements and creating designs.
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What kind of design excersice did you have to present? something related to data modelling? I'm just curious Less
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It was a high-level design for a loan application, including the architecture and data model for the application. Less
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Because I had 12 years as team lead on a top priority application, I had good stories to relate about my experience gathering requirements and creating designs. Less
What is truncate in sql?
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This is a command which is used to delete all the rows from a table. This is a DDL command. After performing this command we cannot rollback data. It is faster. Less
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Truncate is a ddl command .it is used to delete all row at a time in table .it can be rollback. Less
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Truncate command is used to delete the complete data from the table
What's the difference between TRUNCATE and DELETE
2 Answers
How to retrieve unique rows from database without using Distinct or Unique keyword
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One of the method is select a ROWID among duplicate columns
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One method is to use GROUP BY the column(s) you want as distinct.
how to retrieve first five rows from database.
2 Answers↳
select top 5* from table;
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SELECT *FROM table_name ORDER BY column_name_id LIMIT 5;