Domande poste durante i colloqui per Sviluppatore Sql
SQL significa Structured Query Language (linguaggio di query strutturato) e gli Sviluppatori sql si occupano di creare database SQL e le relative applicazioni. Spesso utilizzano tabelle di progettazione e procedure di archiviazione che offrono stabilità, affidabilità e prestazioni. In un colloquio per Sviluppatore sql, i datori di lavoro rivolgono spesso domande sulle conoscenze di programmazione e le abilità di problem-solving.
Domande tipiche dei colloqui per Sviluppatore sql e come rispondere
Ecco le 3 domande più frequenti nei colloqui di lavoro per Sviluppatore sql e consigli su come rispondere:
Domanda 1: Quali sono i tipi di chiavi SQL e quando le utilizzeresti?
Come rispondere: Questa domanda ti permette di dimostrare la tua conoscenza del linguaggio SQL. Parla dei più comuni tipi di chiavi SQL e di come possono identificare righe e colonne nelle tabelle. Le chiavi fungono da identificatori univoci e permettono di recuperare facilmente i dati.
Domanda 2: Quali sono i tipi di normalizzazioni disponibili in SQL e quando le utilizzeresti?
Come rispondere: La normalizzazione SQL serve a organizzare e a ridurre le ridondanze. Puoi dimostrare la tua esperienza parlando dei metodi di normalizzazione che utilizzi con maggior frequenza. Ad esempio, molti sviluppatori suddividono una grossa tabella in più tabelle piccole per agevolare la leggibilità.
Domanda 3: Quali linguaggi di programmazione conosci in maniera approfondita?
Come rispondere: Molti sviluppatori SQL usano anche altri linguaggi di programmazione come JavaScript, HTML, Phyton e PL/SQL. Puoi citare i linguaggi che conosci e spiegare come li hai utilizzati nei tuoi precedenti incarichi. Includi anche eventuali certificazioni che hai ottenuto.
Domande principali poste durante i colloqui
SQL - Trigger, Stored Procedure, SQL Basics, truncate & delete HR - Joins, Multirow functions
4 risposte↳
Trigger is a kind of special stored procedure which will execute automatically when a when an event occures in database server. Meno
↳
Stored procedure is a prepared SQL code which is saved for reusing.
↳
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. Meno
If I knew what the cross apply operator was
4 risposte↳
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)" Meno
↳
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. Meno
↳
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. Meno
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 risposte↳
--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; Meno
↳
--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; Meno
↳
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; Meno
What is the result if we do following Null + 90
3 risposte↳
Always remember null + anything will be null. Also applicable for - ,* ,/
↳
Null
↳
Null .anything+ null is null
Not unexpectedly, the manager was particularly interested in my experience in gathering requirements and creating designs.
3 risposte↳
What kind of design excersice did you have to present? something related to data modelling? I'm just curious Meno
↳
It was a high-level design for a loan application, including the architecture and data model for the application. Meno
↳
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. Meno
What is truncate in sql?
3 risposte↳
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. Meno
↳
Truncate is a ddl command .it is used to delete all row at a time in table .it can be rollback. Meno
↳
Truncate command is used to delete the complete data from the table
What's the difference between TRUNCATE and DELETE
2 risposte
Security
2 risposte↳
The interview was in the morning or noon?
↳
The interview was in the morning or noon? The whole process got completed on the same day including HR? Meno
how to transform a string into comma separated values
2 risposte↳
use split()
↳
Listtag(string,delimeter)
Delete duplicate records from a table
2 risposte↳
referr google
↳
Do they ask to write a program or only sql queries?