SQL Interview Questions (S2)
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This is the 2nd in this series. Check the first one 👇
Disclaimer:
• The questions covered here are mostly conceptual
• I never claim during interviews, only these type of questions are/should be asked
• For interviews, you should have fundamentals strong. And you should be able to provide solutions to practical problems.
• The questions covered here are mostly conceptual
• I never claim during interviews, only these type of questions are/should be asked
• For interviews, you should have fundamentals strong. And you should be able to provide solutions to practical problems.
Series: 2️⃣
Level: Beginner
Topics:
1️⃣ Data Types
2️⃣ Operators
3️⃣ Functions
4️⃣ Views
5️⃣ Aggregation
Level: Beginner
Topics:
1️⃣ Data Types
2️⃣ Operators
3️⃣ Functions
4️⃣ Views
5️⃣ Aggregation
1️⃣ Data Types
* Data Types vary across SQL Vendors like Oracle, MySQL etc. So questions are specific to particular vendors.
✪ When do you define data type of a column?
✪ Can a data type be changed later? What are the restrictions?
* Data Types vary across SQL Vendors like Oracle, MySQL etc. So questions are specific to particular vendors.
✪ When do you define data type of a column?
✪ Can a data type be changed later? What are the restrictions?
✪ What are different numeric data types?
✪ What data type is used to store a boolean?
✪ What data type is used to store bits?
✪ What data type is used for integers?
✪ What data type is used for floating point numbers?
✪ What data type is used to store a boolean?
✪ What data type is used to store bits?
✪ What data type is used for integers?
✪ What data type is used for floating point numbers?
✪ What are different String data types?
✪ What data type is used to store binary data?
✪ What is the difference between CHAR, VARCHAR and VARCHAR2 (Oracle)?
✪ What is a Large Object Data Type?
✪ What are different Large Object Data Types?
✪ What data type is used to store binary data?
✪ What is the difference between CHAR, VARCHAR and VARCHAR2 (Oracle)?
✪ What is a Large Object Data Type?
✪ What are different Large Object Data Types?
✪ What is the difference between BLOB and CLOB?
✪ When should you go for a large object data type instead of a String data type?
✪ What are different Date/Time Data Types?
✪ When should you go for a large object data type instead of a String data type?
✪ What are different Date/Time Data Types?
2️⃣ Operators
✪ What operator to use to verify if all subqueries meet the condition?
✪ What operator to use to verify if any of the subqueries meet the condition?
✪ What operator to use to check if operand is within a range?
✪ What operator to use to verify if all subqueries meet the condition?
✪ What operator to use to verify if any of the subqueries meet the condition?
✪ What operator to use to check if operand is within a range?
✪ What operator to use to check if operand should one of the given values.
✪ What operator to use to check if a subquery returns at least one record?
✪ What operator to use to check if operand matches a pattern?
✪ What is the difference between BETWEEN and IN operators?
✪ What operator to use to check if a subquery returns at least one record?
✪ What operator to use to check if operand matches a pattern?
✪ What is the difference between BETWEEN and IN operators?
✪ What is the difference between = and LIKE operator?
✪ How to check if a field is containing a NULL value?
✪ What are different comparison operators?
✪ What is the operator to check for not equality?
✪ How to check if a field is containing a NULL value?
✪ What are different comparison operators?
✪ What is the operator to check for not equality?
3️⃣ Functions
✪ What is a SQL function?
✪ What function to use to return current system date and time?
✪ What function to use to find length of a text field?
✪ What function to use to convert a text field to upper/lower case?
✪ What is a SQL function?
✪ What function to use to return current system date and time?
✪ What function to use to find length of a text field?
✪ What function to use to convert a text field to upper/lower case?
✪ How to get a substring?
✪ What are different format options to display a text field?
✪ How to round a numeric field to certain precision?
✪ Give examples of some Date/Time functions?
✪ How to get the year/month/date from a Date field?
✪ How to get last day of the month?
✪ What are different format options to display a text field?
✪ How to round a numeric field to certain precision?
✪ Give examples of some Date/Time functions?
✪ How to get the year/month/date from a Date field?
✪ How to get last day of the month?
4️⃣ Views
✪ What is a View?
✪ How is a View different from a Table?
✪ What are various use cases of a View?
✪ Can a View be used to insert/delete records?
✪ How to create/update a View?
✪ What is "WITH CHECK OPTIONS"?
✪ What is a Materialised View? Difference with a View?
✪ What is a View?
✪ How is a View different from a Table?
✪ What are various use cases of a View?
✪ Can a View be used to insert/delete records?
✪ How to create/update a View?
✪ What is "WITH CHECK OPTIONS"?
✪ What is a Materialised View? Difference with a View?
5️⃣ Aggregation
✪ What do you mean by aggregation?
✪ What is the difference between aggregation and projection?
✪ What does "GROUP BY" statement do?
✪ What is the difference between WHERE and HAVING?
✪ Is "ORDER BY" an aggregation statement?
✪ What do you mean by aggregation?
✪ What is the difference between aggregation and projection?
✪ What does "GROUP BY" statement do?
✪ What is the difference between WHERE and HAVING?
✪ Is "ORDER BY" an aggregation statement?
✪ What function to use to find number of records?
✪ What function to use fetch the first/last value for a field?
✪ What function to use to fetch max/min/average value of a field?
✪ What function to use to find summation of all values for a field?
✪ What function to use fetch the first/last value for a field?
✪ What function to use to fetch max/min/average value of a field?
✪ What function to use to find summation of all values for a field?
The next 🧵 of this series will provide questions from
1️⃣ More on DDL
2️⃣ More on DML
3️⃣ Index
4️⃣ Sequence
5️⃣ Trigger
1️⃣ More on DDL
2️⃣ More on DML
3️⃣ Index
4️⃣ Sequence
5️⃣ Trigger
Check 👇 for "Interview Questions" on few other subjects.
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