10+ AgriBird Interview Questions and Answers

Updating customer table

• Use UPDATE statement with SET clause to update table

• Specify the column to be updated and the new value

• Use WHERE clause to specify the condition for updating specific rows

Creating customer table in SQL

• Define the table structure with appropriate data types for each column

• Include columns for customer ID, name, address, email, phone number, etc.

• Set appropriate constraints such as primary key, unique, not null, etc.

• Consider adding additional columns for date of birth, gender, etc. if required

• Create indexes on frequently queried columns for better performance

To delete customer table in SQL, use the DROP TABLE command.

• Use the DROP TABLE command followed by the table name.

• Make sure to backup the data before deleting the table.

• Ensure that there are no dependencies on the table before deleting it.

Triggers are special types of stored procedures that are automatically executed in response to certain events.

• Triggers are used to enforce business rules or to perform complex calculations that involve multiple tables.

• They can be used to audit changes to data, or to replicate data across multiple tables.

• Triggers can be defined to execute before or after an INSERT, UPDATE, or DELETE statement.

• They can also be defined to execute instead of the triggering statement.

• Triggers can ...read more

Cursors are used to retrieve data from a result set one row at a time.

• Cursors are used when we need to perform operations on individual rows of a result set.

• They are declared, opened, fetched, and closed.

• They can be used to update or delete data in a table.

• They can be slow and memory-intensive, so should be used sparingly.

• Example: DECLARE cursor_name CURSOR FOR SELECT * FROM table_name;

• Example: OPEN cursor_name; FETCH NEXT FROM cursor_name INTO @variable;

• Example: CLOSE cursor...read more

Joins are used to combine data from two or more tables based on a related column.

• Types of joins: inner, left, right, full outer

• Syntax: SELECT * FROM table1 JOIN table2 ON table1.column = table2.column

• Can also use aliases for table names and columns

• Joins can be nested or chained together

Indexes are used to improve the performance of SQL queries by reducing the time taken to retrieve data.

• Indexes are created on one or more columns of a table.

• They can be clustered or non-clustered.

• Clustered indexes determine the physical order of data in a table.

• Non-clustered indexes create a separate structure to hold the indexed data.

• Indexes should be used judiciously as they can slow down data modification operations.

Subsets of SQL are different types of SQL languages used for specific purposes.

• Data Definition Language (DDL) - used to define database schema

• Data Manipulation Language (DML) - used to manipulate data in database

• Data Control Language (DCL) - used to control access to database

• Transaction Control Language (TCL) - used to manage transactions

• Examples: CREATE, SELECT, INSERT, UPDATE, DELETE, GRANT, REVOKE, COMMIT, ROLLBACK

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down a table into smaller tables and defining relationships between them.

• There are different levels of normalization, with each level having specific rules to follow.

• Normalization helps to prevent data inconsistencies and anomalies.

• Example: A customer table can be normalized into a customer table and an order table, with a relationship ...read more

Types of joins in SQL are Inner Join, Left Join, Right Join, Full Outer Join, Cross Join.

• Inner Join returns only the matching rows from both tables.

• Left Join returns all the rows from the left table and matching rows from the right table.

• Right Join returns all the rows from the right table and matching rows from the left table.

• Full Outer Join returns all the rows from both tables.

• Cross Join returns the Cartesian product of both tables.