10+ Pure & Cure Healthcare Interview Questions and Answers

A Database Management System (DBMS) is a software that manages and organizes data in a structured manner.

• DBMS is used to create, retrieve, update, and delete data in a database.

• It provides a way to store, manage, and manipulate large amounts of data efficiently.

• DBMS ensures data integrity, security, and concurrency control.

• Examples of popular DBMS include MySQL, Oracle, SQL Server, and PostgreSQL.

SQL is a standard language for managing databases, while MySQL is a specific open-source relational database management system.

• SQL is a standard language used to manage databases, while MySQL is a specific implementation of SQL.

• SQL is an ANSI (American National Standards Institute) standard, while MySQL is an open-source relational database management system.

• SQL can be used with various database management systems like Oracle, SQL Server, etc., while MySQL is a specific datab...read more

Delete command is used to remove specific rows from a table, while truncate command is used to remove all rows from a table.

• Delete command is a DML (Data Manipulation Language) statement.

• Delete command can be used with a WHERE clause to specify the rows to be deleted.

• Truncate command is a DDL (Data Definition Language) statement.

• Truncate command removes all rows from a table, but keeps the table structure intact.

• Truncate command is faster than delete command as it does not ge...read more

Rank and Dense_Rank are window functions used to assign a rank to each row based on a specific column value.

• Rank assigns unique ranks to each row based on the column value.

• Dense_Rank assigns ranks to each row based on the column value, but skips the rank if there are ties.

• Both functions are used with the OVER() clause and ORDER BY statement.

• Example: SELECT name, salary, RANK() OVER(ORDER BY salary DESC) AS rank FROM employees;

• Example: SELECT name, salary, DENSE_RANK() OVER(OR...read more

Primary key uniquely identifies each record in a table, while unique key ensures each value in a column is unique.

• Primary key does not allow NULL values, while unique key allows one NULL value.

• A table can have only one primary key, but multiple unique keys.

• Primary key automatically creates a unique index, while unique key does not.

• Primary key is used to establish relationships between tables, while unique key is used to enforce data integrity.

PIVOT and UNPIVOT are used to transform data from rows to columns and vice versa.

• PIVOT is used to rotate rows into columns

• UNPIVOT is used to rotate columns into rows

• PIVOT requires an aggregate function to be specified

• UNPIVOT requires the column names to be specified

• PIVOT and UNPIVOT are used in T-SQL

• Example: PIVOT (SUM(Sales) FOR Product IN ([A], [B], [C]))

• Example: UNPIVOT (Sales FOR Product IN ([A], [B], [C]))

SET NOCOUNT ON is a T-SQL statement that stops the message indicating the number of rows affected by a Transact-SQL statement.

• SET NOCOUNT ON is used to improve the performance of stored procedures by reducing network traffic.

• It is particularly useful when executing large scripts or batch processes.

• It is also used to suppress the '(X row(s) affected)' message in SQL Server Management Studio.

• To turn it off, use SET NOCOUNT OFF.

Primary key is a unique identifier for each record in a database table.

• Primary key ensures each record in a table is uniquely identified.

• It must contain unique values and cannot have NULL values.

• Primary key can be a single column or a combination of columns.

• Example: 'id' column in a 'users' table can be a primary key.

DBMS stands for Database Management System, which is a software system that allows users to define, create, maintain and control access to databases.

• DBMS is a software system that allows users to interact with databases.

• It helps in defining, creating, maintaining, and controlling access to databases.

• Examples of DBMS include MySQL, Oracle Database, Microsoft SQL Server.

Constraints are rules that are enforced on data columns in a table to ensure data integrity and accuracy.

• Constraints can be used to enforce uniqueness, primary keys, foreign keys, and check conditions on data.

• Examples include UNIQUE, PRIMARY KEY, FOREIGN KEY, and CHECK constraints.

• Constraints help maintain data integrity by preventing invalid data from being inserted into tables.

COALESCE is a function that returns the first non-null value in a list of expressions.

• COALESCE is used to simplify complex SQL statements.

• It can be used with any data type.

• It takes two or more arguments and returns the first non-null value.

• If all arguments are null, it returns null.

• Example: COALESCE(column1, column2, 'N/A') will return the value of column1 if it's not null, else column2 if it's not null, else 'N/A'.

Transactions in SSIS can be implemented using the TransactionOption property in Control Flow tasks.

• Set the TransactionOption property to Required on the Control Flow tasks that need to be included in the transaction.

• Use the TransactionOption property to specify the level of transaction support needed for each task.

• Transactions can be managed using the Distributed Transaction Coordinator (DTC) service.

SQL is a language used to manage and manipulate relational databases.

• SQL stands for Structured Query Language

• It is used to create, modify, and query databases

• Common SQL commands include SELECT, INSERT, UPDATE, and DELETE

• SQL is used in many popular database management systems such as MySQL, Oracle, and Microsoft SQL Server

Aggregate function performs a calculation on a set of values and returns a single value.

• Used with SELECT statement to perform calculations on multiple rows

• Examples: SUM, AVG, COUNT, MAX, MIN

• Can be used with GROUP BY clause to group results by a specific column

Different types of SQL commands include DDL, DML, DCL, and TCL.

• DDL (Data Definition Language) commands are used to create, modify, and delete database objects.

• DML (Data Manipulation Language) commands are used to insert, update, and delete data in a database.

• DCL (Data Control Language) commands are used to control access to data in a database.

• TCL (Transaction Control Language) commands are used to manage transactions in a database.

• Examples of SQL commands include CREATE TABLE...read more