How do I interview a SQL Developer question?
SQL Interview Questions
- What is the difference between SQL and MySQL?
- What are the different subsets of SQL?
- What do you mean by DBMS?
- What do you mean by table and field in SQL?
- What are joins in SQL?
- What is the difference between CHAR and VARCHAR2 datatype in SQL?
- What is the Primary key?
- What are Constraints?
What are the questions asked in SQL interview?
SQL Interview Questions
- What is Database?
- What is DBMS?
- What is RDBMS?
- What is SQL?
- What is the difference between SQL and MySQL?
- What are Tables and Fields?
- What are Constraints in SQL?
- What is a Primary Key?
What are the date functions in SQL?
SQL | Date functions
- NOW(): Returns the current date and time.
- CURDATE(): Returns the current date.
- CURTIME(): Returns the current time.
- DATE(): Extracts the date part of a date or date/time expression.
- EXTRACT(): Returns a single part of a date/time.
- DATE_ADD() : Adds a specified time interval to a date.
What is unique key in SQL?
A unique key is a set of one or more than one fields/columns of a table that uniquely identify a record in a database table. You can say that it is little like primary key but it can accept only one null value and it cannot have duplicate values.
What is SQL Indexing?
A SQL index is used to retrieve data from a database very fast. Indexing a table or view is, without a doubt, one of the best ways to improve the performance of queries and applications. A SQL index is a quick lookup table for finding records users need to search frequently.
How do you calculate top 3 salary in SQL?
To Find the Third Highest Salary Using a Sub-Query,
- SELECT TOP 1 SALARY.
- FROM (
- SELECT DISTINCT TOP 3 SALARY.
- FROM tbl_Employees.
- ORDER BY SALARY DESC.
- ) RESULT.
- ORDER BY SALARY.
How is date stored in SQL?
Internally dates are stored as 2 integers. The first integer is the number of dates before or after the base date (1900/01/01). The second integer stores the number of clock ticks after midnight, each tick is 1⁄300 of a second.
What data type is date in SQL?
Date and Time data types
| Data type | Format | Range |
|---|---|---|
| date | YYYY-MM-DD | 0001-01-01 through 9999-12-31 |
| smalldatetime | YYYY-MM-DD hh:mm:ss | 1900-01-01 through 2079-06-06 |
| datetime | YYYY-MM-DD hh:mm:ss[.nnn] | 1753-01-01 through 9999-12-31 |
| datetime2 | YYYY-MM-DD hh:mm:ss[.nnnnnnn] | 0001-01-01 00:00:00.0000000 through 9999-12-31 23:59:59.9999999 |
What are SQL constraints?
SQL constraints are used to specify rules for the data in a table. Constraints are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the table. If there is any violation between the constraint and the data action, the action is aborted.
What is TCL in SQL?
In SQL, TCL stands for Transaction control language. A single unit of work in a database is formed after the consecutive execution of commands is known as a transaction. There are certain commands present in SQL known as TCL commands that help the user manage the transactions that take place in a database. COMMIT.
What are common entry level SQL Developer interview questions?
1. What is a correlated subquery? Provide an example. This interview question focuses on a developer’s understanding of SQL. A correlated subquery is a query that is tied to an outer query, typically used in a self-join. A subquery can be used anywhere an expression is allowed. There are three types of subquery: 1.
How do I become a SQL Developer?
A SQL developer may work alone for the most part, but may also work as part of a larger software development team. How to Become a SQL Developer. Becoming a SQL developer involves a combination of formal training, usually in a college or university, and practical experience. Certifications tend to increase a developer’s employability and salary.
How should I became a good SQL Server developer?
– Easy installation – More secure – Enhanced Performance – Lower ownership cost
How to become expert in SQL Server developer?
Implementing tables and views (14)