🔳 A ${\color{Red}2}$ Z SQL Solutions ${\color{Green}(using\ SQL\ SERVER)}$

©️ ${\color{grey}Developed\ and\ Maintained\ by:}$ ${\color{blue}Md\ Imtiyaz\ Alam}$

👇 ${\color{red}NAVIGATION}$

🔹 DDL	🔸 SCL	🔹 DML	🔸 DQL	🔹 DCL	🔸 TCL	🔹 SFL
CREATE	USE	INSERT	SELECT	GRANT	COMMIT	CONCAT	REPLACE
ALTER		UPDATE	WILDCARDS	REVOKE	ROLLBACK	SUBSTRING	LEFT/RIGHT
DROP		DELETE	AGGREGATES		SAVEPOINT	CHAR_LENGTH	REVERSE
TRUNCATE			CLAUSES		TRANSACTIONS	LETTER_CASE	REPLICATE
			JOINS			TRIM	FORMAT

◻️ Objective

• The objective of the SQL report is to understand all the Basic SQL-Server Queries/Scripts as well as all kind of String Functions.

◻️ Tech Stack

• SQL Server

◻️ Steps includes

• Creating a Database FSA

• Creating two Tables Student and Exams

• Applying all categories of SQL Commands

  • ${\color{blue}DDL}$: Defines Database structures.

  • ${\color{blue}DML}$: Manipulates Data.

  • ${\color{blue}DQL}$: Queries and Retrieves data.

  • ${\color{blue}DCL}$: Manages access Permissions.

  • ${\color{blue}TCL}$: Controls Transactions.

  • ${\color{blue}SFL}$: Returns a single value.

  • ${\color{blue}WFL}$: Returns a value based on a set of rows.

◻️ Categories of applied SQL Commands

• ${\color{red}DDL}$ (Data Definition Language): It changes the structure of the table like creating a table, deleting a table, altering a table, etc. All the command of DDL are auto-committed that means it permanently save all the changes in the database.

  • CREATE [Define DATA TYPES, CONSTRAINTS here]
  • ALTER (Rename/Add/Drop)
  • DROP
  • TRUNCATE

• ${\color{red}DML}$ (Data Manipulation Language): DML commands are used to modify the database. The command of DML is not auto-committed that means it can't permanently save all the changes in the database. They can be rollback.

  • INSERT
  • UPDATE
  • DELETE

• ${\color{red}DQL}$ (Data Query Language): DQL is used to fetch the data from the database.

  • SELECT [mostly OPERATORS used here]
  • CLAUSES [WHERE, GROUP BY, HAVING, ORDER BY, LIMIT/TOP]
  • JOINS [JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, SELF JOIN, CROSS JOIN, UNION, UNION ALL, INTERSECT]

• ${\color{red}DCL}$ (Data Control Language): DCL commands are used to Grant and Revoke (take back) authority from any database user.

  • GRANT
  • REVOKE

• ${\color{red}TCL}$ (Transaction Control Language): TCL commands can only use with DML commands like INSERT, DELETE and UPDATE only.

  • EGIN TRANSACTION
  • COMMIT
  • ROLLBACK
  • SAVEPOINT

• ${\color{red}SFL}$ (Scalar Functions Library): SFL commands are used to return a single value based on the input provided.

  • STRING FUNCTIONS [CONCAT, SUBSTRING, CHARINDEX, PATINDEX, CHAR LENGTH, LETTER CASE, TRIM, REPLACE, LEFT/RIGHT, REVERSE, REPLICATE, FORMAT]
  • MATHEMATICAL FUNCTIONS [ABS, ROUND, SQRT, CEILING, FLOOR, POWER, EXP, LOG]
  • DATE FUNCTIONS [GETDATE, YEAR, MONTH, DAY, DATEADD, DATEDIFF]
  • CONVERSION FUNCTIONS [CAST, CONVERT, TRY_CAST, TRY_CONVERT]
  • LOGICAL FUNCTIONS [COALESCE, ISNULL]

• ${\color{red}WFL}$ (Windows Functions Library): WFL commands are used to return a value based on a set of rows related to the current row.

  • AGGREGATE FUNCTIONS [COUNT, AVG, SUM, MIN, MAX]
  • RANKING FUNCTIONS [ROW_NUMBER, DENSE_RANK, RANK, NTILE]
  • ANALYTIC FUNCTIONS [CUME_DIST, PERCENT_RANK, FIRST_VALUE, LAST_VALUE, LAG, LEAD]

◻️ Detailed view of all SQL-Server Commands with QUERIES and SCRIPTS

Table: STUDENT
+-------------+-----------+-----------------+--------+-----------------+---------+----------------+-------+-----+------------+
|   Adm_No    | DOJ       | Stud_Name       | Gender | Guardian_Name   | Address | Contact_Number | Class | Fee | Monitor_ID |
+-------------+-----------+-----------------+--------+-----------------+---------+----------------+-------+-----+------------+
|  ROSE00023  | 10/1/2021 | Abu Talha       |   M    | Md Fareed       | Delhi   |   7903077297   |   10  | 400 | NULL       |
|  ROSE00024  | 10/1/2021 | Abu Salesh      |   M    | Md Fareed       | Delhi   |   7903077297   |   8   | 450 | ROSE00023  |
|  ROSE00040  | 10/1/2021 | Md Neyamul      |   M    | Md Shamsuddin   | Chennai |   9661194838   |   7   | 350 | ROSE00023  |
|  ROSE00041  | 6/8/2021  | Ruba Parveen    |   F    | Md Parwez       | Delhi   |   9693461570   |   5   | 275 | ROSE00023  |
|  ROSE00058  | 10/2/2021 | Md Muntazeem    |   M    | Md Naimuddin    | Pune    |   8292149189   |   10  | 325 | ROSE00023  |
|  ROSE00102  | 10/29/2021| Mantasha Khatoon|   F    | Hasnain         | Noida   |   9709148101   |   6   | 250 | ROSE00144  |
|  ROSE00144  | 12/1/2021 | Arju Kumar      |   M    | Ranjit Kumar Sah| Mumbai  |   6206863026   |   8   | 300 | ROSE00058  |
|  ROSE00145  | 12/1/2021 | Roji Kumari     |   F    | Ranjit Kumar Sah| Mumbai  |   6206863026   |   7   | 300 | ROSE00144  |
|  ROSE00172  | 12/4/2021 | Md Azfar        |   M    | Md Mushtaque    | Sikkim  |   7631041561   |   10  | 300 | ROSE00058  |
|  ROSE00331  | 2/3/2023  | Juveria Khatoon |   F    | Saud Alam       | Chennai |   7330859950   |   8   | 300 | ROSE00058  |
|  ROSE00335  | 9/4/2023  | Manish Kumar    |   M    | Ranjan Kumar    | Noida   |   9060609777   |   9   | 350 | ROSE00058  |
|  ROSE00041  | 6/8/2021  | Ruba Parveen    |   F    | Md Parwez       | Delhi   |   9693461570   |   5   | 275 | ROSE00144  |
+-------------+-----------+-----------------+--------+-----------------+---------+----------------+-------+-----+------------+

Table: EXAMS
+------------+--------------+--------------+----------------+------------+
|   Adm_No   | Subject_Code | Subject_Name | Marks_Obtained | Exam_Date  |
+------------+--------------+--------------+----------------+------------+
|  ROSE00001 |    SUB004    | S.St.        |      73        | 12/11/2021 |
|  ROSE00015 |    SUB002    | Science      |      66        | 12/13/2021 |
|  ROSE00023 |    SUB003    | English      |      95        | 12/09/2021 |
|  ROSE00024 |    SUB001    | Mathematics  |      86        | 12/10/2021 |
|  ROSE00040 |    SUB002    | Science      |      80        | 12/08/2021 |
|  ROSE00041 |    SUB002    | Science      |      78        | 12/02/2021 |
|  ROSE00050 |    SUB003    | English      |      56        | 12/14/2021 |
|  ROSE00051 |    SUB001    | Mathematics  |      67        | 12/15/2021 |
|  ROSE00058 |    SUB001    | Mathematics  |      90        | 12/07/2021 |
|  ROSE00065 |    SUB002    | Science      |      81        | 12/16/2021 |
|  ROSE00102 |    SUB001    | Mathematics  |      85        | 12/01/2021 |
|  ROSE00108 |    SUB005    | Computer     |         NULL   |   NULL     |
|  ROSE00144 |    SUB002    | Science      |      74        | 12/05/2021 |
|  ROSE00145 |    SUB003    | English      |      89        | 12/06/2021 |
|  ROSE00172 |    SUB003    | English      |      92        | 12/03/2021 |
|  ROSE00331 |    SUB001    | Mathematics  |      88        | 12/04/2021 |
+------------+--------------+--------------+----------------+------------+

📗 DDL (Data Definition Language)

🔘 ${\color{blue}USE}$ (SCL)

🏠 Home

+---------------------------------------------------------------------------------------------------------------------------------+
| Specifically it comes under SCL (Session Control Language). It is used to select a specific Database to work with in a session. |
+---------------------------------------------------------------------------------------------------------------------------------+

🔸 Using an Existing DATABASE named 'FSA'

      USE FSA;

🔘 ${\color{blue}SCHEMA}$

🏠 Home

+----------------------------------------------------------------------------------------------------------------------------------+
| A schema is like a container for Database objects (tables) that can contain multiple relational tables for a project/department. |
| A database might have multiple schemas                                                                                           |
+----------------------------------------------------------------------------------------------------------------------------------+

🔹 Create a new SCHEMA named 'INSTITUTE'

      CREATE SCHEMA INSTITUTE;

🔹 Create a Table within Schema INSTITUTE

      CREATE TABLE INSTITUTE.RESULT (
                                      Adm_No VARCHAR(20) PRIMARY KEY,
                                      Tot_Marks INT,
                                      Grade VARCHAR(30)
                                    );

🔹 Transfer Table Student into Schema INSTITUTE

      ALTER SCHEMA INSTITUTE TRANSFER dbo.Student;     -- dbo.student means student table in current database (dbo) transferring to schema 'Institute'

      ALTER SCHEMA INSTITUTE TRANSFER HR.Student;     -- HR.student means student table in Old schema (HR) transferring to New schema 'Institute' in current database

🔘 ${\color{blue}CREATE}$

🏠 Home

+--------------------------------------------------------------------------+
| It is used to Create new Databases, Tables, Constraints, Views, Indexes. |
+--------------------------------------------------------------------------+

🔸 Create a new DATABASE named 'FSA'

      CREATE DATABASE FSA;

🔸 Create a new TABLE named 'STUDENT'

      CREATE TABLE STUDENT (
      Adm_No VARCHAR(20) PRIMARY KEY,
      DOJ DATE,
      Stud_Name VARCHAR(50),
      Gender CHAR(10),
      Guardian_Name VARCHAR(50),
      Address VARCHAR(150),
      Contact_Number BIGINT,
      Class INT,
      Fee DECIMAL(10, 2)
      );

🔸 Create the Table Student with CONSTRAINTS (inline)

• 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.

      CREATE TABLE STUDENT (
      Adm_No VARCHAR(10) PRIMARY KEY,                    -- PRIMARY KEY constraint (takes by default NOT NULL) constraint on Admission number
      DOJ DATE NOT NULL,                                 -- Date of Joining, NOT NULL constraint
      Stud_Name VARCHAR(50) NOT NULL,                    -- Student Name, NOT NULL constraint
      Gender CHAR(1) CHECK (Gender IN ('M', 'F')),       -- CHECK constraint ensuring Gender is either 'M' or 'F'
      Guardian_Name VARCHAR(50) NOT NULL,                -- Guardian Name, NOT NULL constraint
      Address VARCHAR(100),                              -- Address
      Contact_Number VARCHAR(15),                        -- Contact Number
      Class INT CHECK (Class BETWEEN 1 AND 12),          -- CHECK constraint ensuring Class is between 1 and 12
      Fee DECIMAL(10, 2) CHECK (Fee > 0)                 -- CHECK constraint ensuring Fee is positive
      Class_Time time(10) DEFAULT '07:05:00' NOT NULL    -- DEFAULT with NOT NULL, 2 constraint, IF USER DOESN'T INSERT ANY VALUE IN Class_Time, WILL AUTOMATICALLY TAKE Default Time '07:05:00'
      );

🔸 Create a VIEW named Class10_Students

• SQL VIEWS are simplified data access, minimize the Query. It is also known as Virtual Table or Query Table because it does not store the rows and columns on the disk. It can lead to performance issues because it is not actual table

      CREATE VIEW Class10_Students AS
      SELECT Adm_No, Stud_Name, Gender, Guardian_Name, Contact_Number, Fee
      FROM STUDENT
      WHERE Class = 10;

• Query to check the VIEWS in a Table

      SELECT * FROM Class10_Students;

🔸 Create an INDEX idx_StudName

• An Index in SQL is like a table of contents in a book. It helps SQL Server quickly locate and retrieve the data from a table without having to scan the entire table.

      CREATE INDEX idx_StudName
      ON STUDENT (Stud_Name);

• Query to check the INDEXES in a Table

      EXEC sp_helpindex 'STUDENT';

• Without an Index (Left side): SQL Server searches the whole table (slow).
• With an Index (Right side): SQL Server jumps directly to the rows you're looking for (fast).

🔘 ${\color{blue}ALTER}$

🏠 Home

+---------------------------------------------------------------------------------------+
| It is used to Alter (change) the structure of the Table and the name of the Database. |
+---------------------------------------------------------------------------------------+

🔹 Alter a DATABASE FSA to 'FSA_new'

      ALTER DATABASE FSA
      Modify Name = FSA_new;

🔹 Rename a Table STUDENTS to 'STUDENT'

      EXEC sp_rename 'Students', 'Student';

🔹 Rename a Table Column Contact_No to 'Contact_Number'

      EXEC sp_rename 'student.Contact_No', 'Contact_Number';

🔹 Add a new column 'Email' to table Student

      ALTER TABLE STUDENT
      ADD Email VARCHAR(100);

🔹 Modify a column (change data type) BIGINT to 'VARCHAR' for Contact_Number column

      ALTER TABLE STUDENT
      ALTER COLUMN Contact_Number VARCHAR(20);

🔹 Modify a column (change length of data type) VARCHAR(50) to 'VARCHAR(100)' for Stud_Name column

      ALTER TABLE STUDENT
      ALTER COLUMN Stud_Name VARCHAR(100);

🔹 Drop a column 'Email' from table Student

      ALTER TABLE STUDENT
      DROP COLUMN Email;

🔹 Add a default value of 300 to 'Fee' column by adding CONSTRAINT

      ALTER TABLE STUDENT
      ADD CONSTRAINT DF_Fee DEFAULT 300 FOR Fee;

🔘 ${\color{blue}DROP}$

🏠 Home

+-----------------------------------------------------------------------+
| It is used to Delete/Remove the objects from the Database completely. |
+-----------------------------------------------------------------------+

🔸 Drop the Database 'FSA'

      DROP DATABASE FSA;

🔸 Drop the Schema 'HR'

      DROP SCHEMA HR;

🔸 Drop the Table 'Student'

      DROP TABLE STUDENT;

🔸 Drop a column 'Email' from table Student

      ALTER TABLE STUDENT
      DROP COLUMN Email;

🔸 Drop the View 'Class10_Students'

      DROP VIEW Class10_Students;

🔸 Drop an Index 'idx_StudName'

      DROP INDEX idx_StudName ON STUDENT;          -- Syntax: Index_Name ON Table_Name

      Drop Index Student.idx_StudName;             -- Syntax: Table_Name.Index_Name

🔘 ${\color{blue}TRUNCATE}$

🏠 Home

+-----------------------------------------------------------------------------------------------------------------------+
| It is used to Remove/Delete all records (rows) from a table, but the table structure (Column names/headings) remains. |
+-----------------------------------------------------------------------------------------------------------------------+

🔹 Truncate the Table 'Student'

      TRUNCATE TABLE STUDENT;

📗 DML (Data Manipulation Language)

🔘 ${\color{blue}INSERT}$

🏠 Home

+-------------------------------------------------+
| It is used to Add new data/values into a table. |
+-------------------------------------------------+

• 'Column names' must match the order of the values.
• 'Dates' should be provided in YYYY-MM-DD format.
• The 'Adm_No' is the primary key and must be unique for each row.

🔹 Insert Data/Values (single record) into a Table Student

      INSERT INTO STUDENT (Adm_No, DOJ, Stud_Name, Gender, Guardian_Name, Address, Contact_Number, Class, Fee)
      VALUES ('ROSE00023', '2021-10-01', 'Abu Talha', 'M', 'Md Fareed', 'Khiripaghar', '7903077297', 10, 400);

🔹 Insert Data/Values (Multiple records) into a Table Student

      INSERT INTO STUDENT (Adm_No, DOJ, Stud_Name, Gender, Guardian_Name, Address, Contact_Number, Class, Fee)
      VALUES 
      ('ROSE00023', '2021-10-01', 'Abu Talha', 'M', 'Md Fareed', 'Khiripaghar', '7903077297', 10, 400),
      ('ROSE00024', '2021-10-01', 'Abu Salesh', 'M', 'Md Fareed', 'Khiripaghar', '7903077297', 8, 450),
      ('ROSE00040', '2021-10-01', 'Md Neyamul', 'M', 'Md Shamsuddin', 'Gauripur', '9661194838', 7, 350),
      ('ROSE00041', '2021-06-08', 'Ruba Parveen', 'F', 'Md Parwez', 'Khiripaghar', '9693461570', 5, 275),
      ('ROSE00058', '2021-10-02', 'Md Muntazeem', 'M', 'Md Naimuddin', 'Rajapur', '8292149189', 10, 325),
      ('ROSE00102', '2021-10-29', 'Mantasha Khatoon', 'F', 'Hasnain', 'Nayadih', '9709148101', 6, 250),
      ('ROSE00144', '2021-12-01', 'Arju Kumar', 'M', 'Ranjit Kumar Sah', 'Chilmil', '6206863026', 8, 300),
      ('ROSE00145', '2021-12-01', 'Roji Kumari', 'F', 'Ranjit Kumar Sah', 'Chilmil', '6206863026', 7, 300),
      ('ROSE00172', '2021-12-04', 'Md Azfar', 'M', 'Md Mushtaque', 'Maghota', '7631041561', 10, 300),
      ('ROSE00331', '2023-02-03', 'Juveria Khatoon', 'F', 'Saud Alam', 'Chihar', '7330859950', 8, 300);

🔘 ${\color{blue}UPDATE}$

🏠 Home

+-----------------------------------------------------------+
| It is used to Modify existing data/values within a table. |
+-----------------------------------------------------------+

• The WHERE clause ensures that only the specified row (e.g., Adm_No = 'ROSE00023') is updated.
• Without WHERE, all rows in the table would be updated!

🔸 Update (SET) Single value/row (Class) in a Table 'Student'

     UPDATE STUDENT
     SET Class = 9
     WHERE Adm_No = 'ROSE00040';

🔸 Update (SET) Multiple (same) values/same Column (Gender) in a Table 'Student' if Column has NULL values

     UPDATE STUDENT
     SET Gender = 'M'
     Where Gender IS NULL;

🔸 Update (SET) Multiple (different) values/same row (Stud_Name, Fee and DOJ) in a Table 'Student'

     UPDATE STUDENT
     SET Stud_Name = 'Abu Talha Khan', Fee = 450, DOJ = '2021-10-04'
     WHERE Adm_No = 'ROSE00023';

🔸 Update (SET) Multiple (same) values/same Column (Gender) in a Table 'Student'

     UPDATE STUDENT
     SET Gender = 'Fem'
     WHERE Adm_No IN ('ROSE00145', 'ROSE00331', 'ROSE00041');

🔸 Update (SET with CASE, ELSE, END) Multiple (different) values/different Column (FEE) in a Table 'Student'

• for ELSE statement when we keep the same column name (i.e. "Fee") as SET statement, then Rest columns value remain same

        UPDATE STUDENT
           SET Fee = CASE
               WHEN Adm_No='ROSE00024' THEN 450
               WHEN Adm_No='ROSE00041' THEN 275
               WHEN Adm_No='ROSE00058' THEN 325
               WHEN Adm_No='ROSE00102' THEN 250
               WHEN Adm_No='ROSE00023' THEN 400
               WHEN Adm_No='ROSE00040' THEN 350
           ELSE Fee                                       -- for ELSE statement when we keep the same column name (i.e. "Fee") as SET statement, then Rest columns value remain same
        END;

🔸 Update (SET with CASE, ELSE, END) Multiple (different) values/different Column (FEE) in a Table 'Student'

• for ELSE statement when we keep any value (i.e. "199") different from SET statement, then Rest columns take the default value "199"

        UPDATE STUDENT
           SET Fee = CASE
               WHEN Adm_No='ROSE00024' THEN 450
               WHEN Adm_No='ROSE00041' THEN 275
               WHEN Adm_No='ROSE00058' THEN 325
               WHEN Adm_No='ROSE00102' THEN 250
               WHEN Adm_No='ROSE00023' THEN 400
               WHEN Adm_No='ROSE00040' THEN 350
           ELSE 199                                       -- for ELSE statement when we keep any value (i.e. "199") different from SET statement, then Rest columns take the default value "199"
        END;

🔘 ${\color{blue}DELETE}$

🏠 Home

+-----------------------------------------+
| It is used to Remove data from a table. |
+-----------------------------------------+

• WHERE clause specifies which rows to delete (e.g., rows with Adm_No = 'ROSE00023').
• If you omit the WHERE clause, all rows in the table will be deleted!

🔹 Delete single Row/Record from a Table Student by the reference of one Primary-Key Value

      DELETE FROM STUDENT
      WHERE Adm_No = 'ROSE00023';                         -- One Primary-Key Value

🔹 Delete Multiple Rows/Records from a Table Student by the reference of many Primary-Key Values

• The IN operator allows you to match multiple values in a column.
• This query will delete Both rows where Adm_No is either 'ROSE00023' or 'ROSE00024'.

      DELETE FROM STUDENT
      WHERE Adm_No IN ('ROSE00023', 'ROSE00024');         -- Multiple Primary-Key Values by using "IN" operator

🔹 Delete Multiple Rows/Records from a Table Student by the reference of one Non-Key Value

      DELETE FROM STUDENT
      WHERE Class = 10;                                   -- One Non-Key Value

🔘 ${\color{blue}STORED\ PROCEDURE}$

🏠 Home

+---------------------------------------------------------------------------------------------+
| It is a precompiled SQL code stored in the database, that can be executed as a single unit. |
| If any SQL query need to write again and again then same can be saved as Stored Procedure.  |
+---------------------------------------------------------------------------------------------+

🔹 CREATE Stored Procedure named StudentInfo from Student Table

      CREATE PROCEDURE StudentInfo
      AS                                  -- BEGIN and END are used to define the start and end of the executable block within a stored procedure,
      BEGIN                               -- allowing multiple SQL statements to be grouped together. 
           SELECT * FROM Student;      
      END;
      GO                                  -- 'GO' is not an actual SQL command, It is a part of SSMS which indicates end of Batch (group of commands) in SSMS

📗 DQL (Data Query Language)

🔘 ${\color{blue}SELEC T}$

🏠 Home

+------------------------------------------------------------+
| It is used to Retrieve/Fetch data from one or more tables. |
+------------------------------------------------------------+

🔸 Select Current Date and Time

      SELECT Getdate() AS [Current Date and Time];             -- To check Current DATE and TIME

      SELECT Sysdatetime() AS [Current Date and Time];         -- To check Current DATE and TIME

      SELECT Cast(Getdate() AS Date) AS [Current Date];        -- To check Current DATE only

      SELECT Cast(Sysdatetime() AS Date) AS [Current Date];    -- To check Current DATE only

🔸 Select All Databases of SQL-Server

      SELECT * FROM sys.databases;

🔸 Select All Tables from a current session Database

      SELECT * FROM sys.tables;

🔸 Select All Columns from a Table 'Student'

      SELECT * FROM STUDENT;

🔸 Select All Columns from a Table 'Exams'

      SELECT * FROM EXAMS;

🔸 Select Table 'Exams' Columns from Schema 'Institute'

      SELECT * FROM INSTITUTE.EXAMS;         -- Select Records from Schema (Institute), Table (Exams) = Schema.Table

🔸 Select Table 'Exams' Columns from Schema 'Institute' in Database 'FSA'

      SELECT * FROM FSA.INSTITUTE.EXAMS;         -- Select Records from Database (FSA), Schema (Institute), Table (Exams) = Database.Schema.Table

🔸 Select Specific Columns from a Table 'Student'

      SELECT Adm_No, Stud_Name, Class, Fee 
      FROM EXAMS;

🔸 Select Records with a Arithmetic Operators` (+, -, *, /, %)

      SELECT Stud_Name, Fee, Fee + 50 AS Increased_Fee
      FROM STUDENT;                                            -- Addition (+): Increase the FEE by 50 for each student

      SELECT Stud_Name, Fee, Fee - 100 AS Reduced_Fee
      FROM STUDENT;                                            -- Subtraction (-): Decrease 100 from the Fee for each student

      SELECT Stud_Name, Fee, Fee * 2 AS Doubled_Fee
      FROM STUDENT;                                            -- Multiplication (*): Multiply the Fee by 2 for each student

      SELECT Stud_Name, Fee, Fee / 2 AS Halved_Fee
      FROM STUDENT;                                            -- Division (/): Divide the Fee by 2 for each student

      SELECT Stud_Name, Fee, Fee % 100 AS Remainder_Fee
      FROM STUDENT;                                            -- Modulus (%): Find the remainder when Fee is divided by 100

🔸 Select Records with a Condition (Comparison Operators: =, >, <, >=, <=, !=, <>, !<, !>)

      SELECT * FROM STUDENT
      WHERE Class = 10;                     -- Return all records from STUDENT Table for 10th Class

      SELECT * FROM STUDENT
      WHERE Class <> 5;                     -- Return all records from STUDENT Table for all classes EXCEPT 5th Class [Class not equal to (<> or !=) 5]

      SELECT * FROM STUDENT
      WHERE Fee >= 350;                     -- Return all records from STUDENT Table for those whose Fee more than or equal to 350

      SELECT * FROM STUDENT
      WHERE Fee !> 350;                     -- Return all records from STUDENT Table for those whose Fee not more than 350

🔸 Select Records with Conditions by Logical Operators: AND, OR, NOT, IN, BETWEEN, LIKE, ANY/SOME, ALL, IS NULL

      SELECT * FROM STUDENT
      WHERE Fee > 300 AND Class = 8;        -- Return all records from STUDENT Table for 8th Class whose Fee more than 300

      SELECT * FROM STUDENT
      WHERE Class = 10 OR Class = 9;         -- Return all records from STUDENT Table for 8th Class whose Fee more than 300

      SELECT * FROM STUDENT
      WHERE NOT Fee > 350 AND Gender = 'F';   -- Return all records from STUDENT Table whose fee not more than 350 for Females

      SELECT * FROM STUDENT
      WHERE DOJ BETWEEN '2021-10-01' AND '2021-12-04';                 -- Return all records from STUDENT Table who joined between date range

      SELECT * FROM STUDENT
      WHERE Stud_Name LIKE 'Ru%' OR Stud_Name LIKE '%oon';             -- Used 'WILDCARD %' here

      SELECT * FROM EXAMS
      WHERE Subject_Name IN('Science', 'English', 'Computer') AND Marks_Obtained > 90;    -- Return all records from EXAMS Table who get marks above 90 IN Science, English and Computer

      SELECT * FROM STUDENT
      WHERE Fee > ANY (SELECT Fee FROM STUDENT WHERE Class = 8);        -- Find students whose Fee is greater than ANY student in Class 8

      SELECT * FROM STUDENT                                              -- ANY=SOME: SOME is functionally equivalent to ANY in SQL
      WHERE Fee = SOME (SELECT Fee FROM STUDENT WHERE Class = 8);        -- Find students whose Fee is equal to SOME student in Class 8

      SELECT * FROM STUDENT
      WHERE Fee > ALL (SELECT Fee FROM STUDENT WHERE Class = 8);         -- Find students whose Fee is greater than ALL students in Class 8

      SELECT Stud_Name FROM STUDENT                                      -- Find students whose Fee is greater than ALL students in Class 8
      WHERE EXISTS (SELECT * FROM STUDENT WHERE Class = 10);             -- If an entry EXISTS, it returns the student's name

      SELECT * FROM EXAMS
      WHERE Marks_Obtained IS NULL;                                     -- Find students whose Marks_Obtained IS NULL (if any such values exist)

🔸 Select Records with NESTED Queries/SUBqueries

      SELECT * FROM EXAMS
      WHERE Marks_Obtained > (SELECT AVG(Marks_Obtained) FROM EXAMS);        -- Return all records greater than average marks

🔸 Select Records with Order/Sorting (ASC or DESC)

      SELECT * FROM STUDENT
      ORDER BY Stud_Name ASC;

      SELECT * FROM STUDENT
      ORDER BY Class DESC;

🔘 ${\color{blue}WILDCARDS}$

🏠 Home

+------------------------------------------------------------------------+
| It is used to search for patterns with LIKE clause within string data. |
+------------------------------------------------------------------------+

🔹 Select Records with Wildcard %

      SELECT * FROM STUDENT
      WHERE Guardian_Name LIKE 'M%';        -- Return all records from STUDENT Table where Guardian Name STARTS with letter 'M'

      SELECT * FROM EXAMS
      WHERE Subject_Name LIKE '%e';         -- Return all records from EXAMS Table where Subject Name ENDS with letter 'e'

      SELECT * FROM EXAMS
      WHERE Subject_Name LIKE 'M%s';        -- Return all records from EXAMS Table where Subject name STARTS with letter 'M' and ENDS with letter 's'

      SELECT * FROM EXAMS
      WHERE Addres LIKE '%ur%';             -- Return all records from EXAMS Table where Addres CONTAINS phrase 'ur'

🔹 Select Records with Wildcard _

      SELECT * FROM STUDENT
      WHERE Addres LIKE '_hilmil';           -- Return all records from STUDENT Table where Addres STARTS with ANY ONE character, FOLLOWED "hilmil"

      SELECT * FROM EXAMS
      WHERE Subject_Name LIKE 'Englis_';     -- Return all records from EXAMS Table where subject name STARTS with "Englis", ENDS with ANY ONE character

      SELECT * FROM EXAMS                    -- Return all records from EXAMS Table where subject name STARTS with ANY 2 characters....
      WHERE Subject_Name LIKE '__gl___';     -- FOLLOWED by "gl" and ENDS with ANY 3 characters

      SELECT * FROM EXAMS                    -- Return all records from EXAMS Table where subject code starts with "S"....
      WHERE Subject_Code LIKE 'S__002';      -- followed by any 2 characters and ends with '002'

      SELECT * FROM STUDENT
      WHERE Addres LIKE '_a%';               -- Return all records from STUDENT Table where addres starts with any one character, 'a' at 2nd position

🔹 Select Records with Wildcard []

      SELECT * FROM STUDENT
      WHERE Addres LIKE '[a-g]%';            -- Return all records from STUDENT Table where Addres starts with any one letter "from 'a' to 'g'" (a,b,c,d,e,f OR g)

      SELECT * FROM STUDENT
      WHERE Stud_Name LIKE 'A[nr]%'          -- Matches names starting with "An" or "Ar"

      SELECT * FROM STUDENT
      WHERE Guardian_Name LIKE '[rhs]%';    -- Return all records from STUDENT Table where Guardian Name STARTS with letter 'r' or 'h' or 's'

      SELECT * FROM STUDENT
      WHERE Guardian_Name LIKE '[^rhs]%';    -- Return all records from STUDENT Table where Guardian Name NOT STARTS with letter 'r' or 'h' or 's'

🔘 ${\color{blue}AGGREGATE\ FUNCTIONS}$

🏠 Home

+----------------------------------------------------------------------------------+
| It is used to perform a calculation on multiple rows and returns a single value. |
| It is commonly used to summarize or analyze data.                                |
+----------------------------------------------------------------------------------+

🔸 Select Records using COUNT

      SELECT COUNT(*) AS TotalStudents
      FROM STUDENT;                          -- Count the total number of records/rows from student table

🔸 Select Records using SUM

      SELECT SUM(Fee) AS TotalFees
      FROM STUDENT;                          -- Calculate the total fees of all students from student table

🔸 Select Records using AVG

      SELECT AVG(Fee) AS AverageFee
      FROM STUDENT;                          -- Calculate the average fee of students from student table

🔸 Select Records using MIN

      SELECT MIN(Fee) AS MinimumFee
      FROM STUDENT;                          -- Find the minimum fee paid by a student from student table

🔸 Select Records using MAX

      SELECT MAX(Fee) AS MinimumFee
      FROM STUDENT;                          -- Find the maximum fee paid by a student from student table

🔸 Select Records using COUNT with GROUP BY and HAVING clauses

      SELECT Class, COUNT(*) AS NumberOfStudents
      FROM STUDENT
      GROUP BY Class
      HAVING COUNT(*) > 2;                   -- Find classes with more than 2 students

🔘 ${\color{blue}CLAUSES}$

🏠 Home

+------------------------------------------------------------------------+
| It is used to specify conditions or actions to be applied to the data. |
| Clauses help to filter, group, sort, or limit the results of a query.  |
+------------------------------------------------------------------------+

🔹 Select Records using WHERE

• WHERE clause: Filter rows based on a condition before grouping.

       SELECT * FROM STUDENT
       WHERE Class = 8;                                      -- Retrieve all students in Class 8

🔹 Select Records using ORDER BY

• ORDER BY clause: Sort the result set.

       SELECT * FROM STUDENT
       ORDER BY Stud_Name ASC;                               -- Retrieve all students sorted by Stud_Name in ascending order

       SELECT * FROM STUDENT
       WHERE Gender = 'M'
       ORDER BY Stud_Name ASC;                               -- Retrieve all male students sorted by Stud_Name in ascending order

🔹 Select Records using GROUP BY

• GROUP BY clause: Group rows based on one or more columns.

       SELECT Class, SUM(Fee) AS [Total Fee by Class]
       FROM STUDENT
       GROUP BY Class;                                       -- Sum the fee of students in each class

       SELECT Class, SUM(Fee) AS [Total Fee by Class]
       FROM STUDENT
       WHERE Fee > 300                                       -- Filters rows where Fee is greater than 300
       GROUP BY Class
       ORDER BY Class DESC;                                  -- Sum the fee of students in each class whose fee more than 300 sorted by Class in Descending order

🔹 Select Records using HAVING

• HAVING clause: Filter groups after Grouping to filter results on Aggregation.

       SELECT Class, COUNT(*) AS NumberOfStudents
       FROM STUDENT
       GROUP BY Class
       HAVING COUNT(*) > 2;                                  -- Find classes with more than 2 students

       SELECT Class, SUM(Fee) AS [Total Fee by Class]
       FROM STUDENT
       GROUP BY Class
       HAVING SUM(Fee) > 500                                 -- Filters groups where the total Fee is greater than 500
       ORDER BY Class DESC;

🔹 Select Records using TOP/OFFSET/FETCH

• TOP clause: Limit the number of rows returned.

       SELECT TOP 5 * FROM STUDENT
       ORDER BY Fee DESC;                                    -- Retrieve the top 5 students by Fee in descending order

       SELECT TOP 5 Adm_No, Stud_Name FROM STUDENT
       ORDER BY Fee DESC;                                    -- Retrieve the top 5 students table Adm_No and Stud_Name columns by Fee in descending order

       SELECT Adm_No, Marks_Obtained FROM EXAMS
       ORDER BY Marks_Obtained DESC
       OFFSET 3 ROWS                                         -- Skip (Offset) 1st 3 rows and then return next 5 rows
       FETCH NEXT 5 ROWS ONLY;                               -- Retrieve the top 5 EXAMS table Adm_No and Marks_Obtained columns by Marks_Obtained in descending order

🔹 Select Records using DISTINCT

• DISTINCT clause: Select unique values only.

       SELECT DISTINCT Class FROM STUDENT;                   -- Retrieve the distinct/unique classes of students

       SELECT DISTINCT Class FROM STUDENT
       WHERE Fee > 300;                                      -- Retrieve the distinct classes/unique of students where student fee more than 300

🔹 Select Records using JOIN

• JOIN clause: Combines rows from two or more tables.

       SELECT S.*, E.Subject_Name, E.Marks_Obtained          -- Fetch all columns (*) from Student Table and Subject & Marks obtained from Exams Table
       FROM STUDENT S
       INNER JOIN EXAMS E
       ON S.Adm_No = E.Adm_No;

🔘 ${\color{blue}JOIN_S}$

🏠 Home

+---------------------------------------------------------------------------------------------+
| It is used to combine rows from two or more tables, based on a related column between them. |
+---------------------------------------------------------------------------------------------+

🔸 Fetch Student Records using (INNER) JOIN

• (INNER) JOIN: Returns records that have only MATCHING (Common) VALUES IN BOTH TABLES.

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      INNER JOIN EXAMS E
      ON S.Adm_No = E.Adm_No;                             -- Returns the Admission No., student names along with the subjects and marks they obtained in the exams

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      JOIN EXAMS E                                        -- JOIN or Inner JOIN works similarly
      ON S.Adm_No = E.Adm_No
      WHERE S.Class = 10;                                 -- Returns the students of class 10 and their respective exam marks

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      INNER JOIN EXAMS E
      ON S.Adm_No = E.Adm_No
      WHERE E.Marks_Obtained > 85;                        -- Fetches students who scored more than 85 marks in any exam

🔸 Fetch Student Records using LEFT (OUTER) JOIN

• LEFT (OUTER) JOIN: Returns all records from the LEFT TABLE, and the matched records from the RIGHT TABLE.

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      LEFT JOIN EXAMS E
      ON S.Adm_No = E.Adm_No;           -- Fetches all students, including those who may not have appeared in any exams

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      LEFT OUTER JOIN EXAMS E           -- LEFT OUTER JOIN acts as similar to LEFT JOIN
      ON S.Adm_No = E.Adm_No;

🔸 Fetch Student Records using RIGHT (OUTER) JOIN

• RIGHT (OUTER) JOIN: Returns all records from the RIGHT TABLE, and the matched records from the LEFT TABLE.

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      RIGHT JOIN EXAMS E
      ON S.Adm_No = E.Adm_No;           -- Fetches all exam records, even if some students may not exist in the STUDENT table (Null Values for Marks_Obtained)

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      RIGHT OUTER JOIN EXAMS E
      ON S.Adm_No = E.Adm_No;           -- RIGHT OUTER JOIN acts as similar to RIGHT JOIN

🔸 Fetch Student Records using FULL (OUTER) JOIN

• FULL (OUTER) JOIN: Returns all records when there is a match in either LEFT or RIGHT TABLE.

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      FULL OUTER JOIN EXAMS E
      ON S.Adm_No = E.Adm_No;           -- Fetches all exam records, even if some students may not exist in the STUDENT table (Null Values)

      SELECT S.Adm_No, S.Stud_Name, E.Subject_Name, E.Marks_Obtained
      FROM STUDENT S
      FULL JOIN EXAMS E
      ON S.Adm_No = E.Adm_No;           --  FULL JOIN acts as similar to FULL OUTER JOIN

🔸 Fetch Student Records using SELF JOIN

• SELF JOIN: A self join is when a table is joined with itself. It is useful for hierarchical or recursive data structures. Let's say we want to find students from the same address (students who live in the same location).

      SELECT S1.Stud_Name AS Student1, S2.Stud_Name AS Student2, S1.Addres
      FROM STUDENT S1
      INNER JOIN STUDENT S2
      ON S1.Addres = S2.Addres
      WHERE S1.Adm_No <> S2.Adm_No;    -- This query matches students who live at the same address but ensures they are not the same student by using S1.Adm_No <> S2.Adm_No

🔸 Fetch Student Records using CROSS JOIN

• CROSS JOIN: It combines every row of the first table with every row of the second table. Example: Cross join students with their subjects.

      SELECT S.Stud_Name, E.Subject_Name
      FROM STUDENT S
      CROSS JOIN EXAMS E;              -- Pairs every student with every subject, producing a large set of combinations

🔸 Fetch Student Records using UNION

• UNION: It Combines the results of two or more SELECT statements. The UNION operator only returns distinct records from one or more tables.

      SELECT Adm_No FROM STUDENT
      UNION
      SELECT Guardian_Name FROM STUDENT;

📗 DCL (Data Control Language)

🔘 ${\color{blue}GRANT}$

🏠 Home

+----------------------------------------------------------+
| It is used to give a user access rights to the database. |
+----------------------------------------------------------+

🔹 Grant SELECT Permission on a Table

      GRANT SELECT ON STUDENT TO UserA;                      -- Gives the user 'UserA' the ability to perform SELECT queries on the STUDENT table

🔹 Grant INSERT and UPDATE Permissions on a Table

      GRANT INSERT, UPDATE ON STUDENT TO UserA;              -- Allows UserA to insert new records and update existing ones in the STUDENT table

🔘 ${\color{blue}REVOKE}$

🏠 Home

+----------------------------------------------------------------------------------+
| It is used to remove access rights from the database which is granted to a user. |
+----------------------------------------------------------------------------------+

🔸 Revoke SELECT Permission on a Table

      REVOKE SELECT ON STUDENT TO UserA;                      -- Removes the SELECT permission, so UserA can no longer query data from the STUDENT table

🔸 Revoke INSERT and UPDATE Permissions on a Table

      REVOKE INSERT, UPDATE ON STUDENT TO UserA;              -- Removes the ability for UserA to insert new records or update existing ones in the STUDENT table

📗 TCL (Transaction Control Language)

🔘 ${\color{blue}COMMIT}$

🏠 Home

+--------------------------------------------------------------------------------------+
| It is used to save the current transaction permanently in the database.              |
| Once a COMMIT is executed, the changes are made permanent and cannot be rolled back. |
+--------------------------------------------------------------------------------------+

🔹 Insert a Record and Commit the Transaction

      BEGIN TRANSACTION;

      INSERT INTO STUDENT (Adm_No, DOJ, Stud_Name, Gender, Guardian_Name, Address, Contact_Number, Class, Fee)
      VALUES ('ROSE00332', '2023-09-15', 'John Doe', 'M', 'Richard Doe', 'Greenfield', '1234567890', 8, 350);

      COMMIT;

🔘 ${\color{blue}ROLLBACK}$

🏠 Home

+-------------------------------------------------------------+
| It is used to Undo changes made in the current transaction. |
+-------------------------------------------------------------+

🔸 Insert a Record, but Rollback the Transaction

      BEGIN TRANSACTION;

      INSERT INTO STUDENT (Adm_No, DOJ, Stud_Name, Gender, Guardian_Name, Address, Contact_Number, Class, Fee)
      VALUES ('ROSE00333', '2023-09-15', 'Jane Smith', 'F', 'John Smith', 'Blueville', '9876543210', 7, 300);

      ROLLBACK;                                                                      -- If something goes wrong, rollback the transaction

🔘 ${\color{blue}SAVEPOINT}$

🏠 Home

+----------------------------------------------------------------------------------+
| It is used to set a point within a transaction to which you can roll back later. |
+----------------------------------------------------------------------------------+

🔹 Using SAVEPOINT in a Transaction

      BEGIN TRANSACTION;

      INSERT INTO STUDENT (Adm_No, DOJ, Stud_Name, Gender, Guardian_Name, Address, Contact_Number, Class, Fee)
      VALUES ('ROSE00334', '2023-09-15', 'Alice Brown', 'F', 'Sam Brown', 'Redtown', '1122334455', 6, 250);

      SAVEPOINT Save1;

      INSERT INTO STUDENT (Adm_No, DOJ, Stud_Name, Gender, Guardian_Name, Address, Contact_Number, Class, Fee)
      VALUES ('ROSE00335', '2023-09-15', 'Bob White', 'M', 'Jim White', 'Greenville', '5566778899', 5, 275);

      ROLLBACK TRANSACTION Save1;                                                  -- Something goes wrong, rollback to the savepoint

      COMMIT;                                                                      -- Now commit the first insert, but not the second

🔘 ${\color{blue}SET\ TRANSACTION}$

🏠 Home

+------------------------------------------------------------------------------------+
| It is used to specify characteristics for the transaction (e.g., isolation level). |
+------------------------------------------------------------------------------------+

🔸 Using SET TRANSACTION ISOLATION LEVEL

      SET TRANSACTION ISOLATION LEVEL READ COMMITTED;

      BEGIN TRANSACTION;
                                                                                           -- Query or Insert/Update/Delete operations                                                      

      INSERT INTO STUDENT (Adm_No, DOJ, Stud_Name, Gender, Guardian_Name, Address, Contact_Number, Class, Fee)
      VALUES ('ROSE00336', '2023-09-15', 'Charlie Green', 'M', 'Paul Green', 'Bluefield', '9988776655', 9, 400);

      COMMIT;

📗 SFL (Scalar Functions Library)

🔘 ${\color{blue}STRING\ FUNCTIONS}$

🏠 Home

+------------------------------------------------------------------------------------------------+
| It is used to manipulate string data for tasks like concatenation, extraction, and formatting. |
+------------------------------------------------------------------------------------------------+

🔹 Concatenate Adm_No and Stud_Name

      SELECT CONCAT(Adm_No, ' - ', Stud_Name) AS StudentDetails
      FROM STUDENT;

🔹 Concatenate Stud_Name and Guardian_Name

      SELECT CONCAT('Name: ', Stud_Name, ', Guardian: ', Guardian_Name) AS [Full Details]
      FROM STUDENT;

🔸 Extract first 3 characters of Stud_Name

      SELECT SUBSTRING(Stud_Name, 1, 3) AS ShortName
      FROM STUDENT;

🔸 Extract 4 characters from Adm_No starting at position 5

      SELECT SUBSTRING(Adm_No, 5, 4) AS PartAdmNo
      FROM STUDENT;

🔹 Find the length of Stud_Name (LEN)

      SELECT Stud_Name, LEN(Stud_Name) AS NameLength
      FROM STUDENT;

🔹 Find the length of Address (LEN)

      SELECT Address, LEN(Address) AS AddressLength
      FROM STUDENT;

🔹 Find the position of Md in Stud_Name (CHARINDEX)

      SELECT CHARINDEX('Md', Stud_Name) AS Md_Position
      FROM STUDENT;

🔹 Find the starting position of pattern R in Stud_Name (PATINDEX)

      SELECT PATINDEX('%R%', Stud_Name) AS R_Position
      FROM STUDENT;

🔸 Convert Stud_Name to UPPERCASE

      SELECT UPPER(Stud_Name) AS UpperCaseName
      FROM STUDENT;

🔸 Convert Address to lowercase

      SELECT LOWER(Address) AS LowerCaseAddress
      FROM STUDENT;

🔹 Remove spaces from Contact_Number

      SELECT TRIM(Contact_Number) AS TrimmedContact
      FROM STUDENT;

🔹 Remove leading spaces from Stud_Name

      SELECT LTRIM(Stud_Name) AS Trimmed_Left_Name
      FROM STUDENT;

🔹 Remove trailing spaces from Stud_Name

      SELECT RTRIM(Stud_Name) AS Trimmed_Right_Name
      FROM STUDENT;

🔸 Replace 'Md' with 'Mr.' in Stud_Name

      SELECT REPLACE(Stud_Name, 'Md', 'Mr.') AS Updated_Name
      FROM STUDENT;

🔸 Replace hyphen - with space in Adm_No

      SELECT REPLACE(Adm_No, '-', ' ') AS ModifiedAdmNo
      FROM STUDENT;

🔸 Insert Dr. at the beginning of Stud_Name

      SELECT STUFF(Stud_Name, 1, 0, 'Dr. ') AS Stuffed_Name
      FROM STUDENT;

🔹 Extract first 5 characters of Adm_No

      SELECT LEFT(Adm_No, 5) AS FirstFive
      FROM STUDENT;

🔹 Extract last 4 characters of Contact_Number

      SELECT RIGHT(Contact_Number, 4) AS LastFourDigits
      FROM STUDENT;

🔸 Reverse Adm_No

      SELECT REVERSE(Adm_No) AS ReversedAdmNo               -- reverse the order of characters in a string
      FROM STUDENT;

🔸 Reverse Stud_Name

      SELECT REVERSE(Stud_Name) AS ReversedName             -- reverse the order of characters in a string
      FROM STUDENT;

🔹 Repeat '*' symbol 5 times

      SELECT REPLICATE('*', 5) AS Stars                      -- Return star (*) 5 times
      FROM STUDENT;

🔹 Repeat Stud_Name twice

      SELECT REPLICATE(Stud_Name, 2) AS DoubledName          -- Return the same Student Name 2 times
      FROM STUDENT;

🔸 Format Contact_Number with dashes

      SELECT FORMAT(Contact_Number, '###-###-####') AS FormattedContact   -- format a value according to a format
      FROM STUDENT;

🔸 Format DOJ in MM/dd/yyyy format

      SELECT FORMAT(DOJ, 'MM/dd/yyyy') AS FormattedDOJ
      FROM STUDENT;