SQL - Syntax pt.1

Question 1

SQL statements

In SQL * means

Answer 1

All record

Question 2

SQL statements

used to select data from a database.

Answer 2

SQL SELECT Statement

SELECT CustomerName, City FROM Customers;

Syntax:

SELECT column1, column2, …
FROM table_name;

Question 3

SQL statements

is used to return only different values.

Answer 3

SQL DISTINCT Clause

SELECT DISTINCT Country FROM Customers;

Syntax:

SELECT DISTINCT column1, column2, …
FROM table_name;

Question 4

SQL statements

used to filter records.

It is used to extract only those records that fulfill a specified condition

Answer 4

SQL WHERE Clause

SELECT * FROM Customers
WHERE Country=’Mexico’;

Syntax:

SELECT column1, column2, …
FROM table_name
WHERE condition;

Question 5

SQL statements

this operator is used when all the conditions are true.

Answer 5

AND operator

SELECT * FROM Customers
WHERE Country = ‘Germany’ AND Name = ‘Tom’;

Syntax:

SELECT column1, column2, …
FROM table_name
WHERE condition1 AND condition2 AND condition3 …;

Question 6

SQL statements

operator is used if any one of the conditions are true.

Answer 6

OR operator

SELECT *
FROM Customers
WHERE Country = ‘Germany’ OR Country = ‘Spain’

Syntax:

SELECT column1, column2, …
FROM table_name
WHERE condition1 OR condition2 OR condition3 …;

Question 7

SQL statements

allows you to specify multiple values in a WHERE clause.

Answer 7

SQL IN Clause

SELECT * FROM Customers
WHERE Country IN (‘Germany’, ‘France’, ‘UK’);

Syntax:

SELECT column_name(s)
FROM table_name
WHERE column_name IN (value1, value2, …);

Question 8

SQL statements

selects values within a given range. The values can be numbers, text, or dates.

Answer 8

SQL BETWEEN Clause

SELECT * FROM Products
WHERE Price BETWEEN 10 AND 20;

Syntax:

SELECT column_name(s)
FROM table_name
WHERE column_name BETWEEN value1 AND value2;

Question 9

SQL statements

is used in a WHERE clause to search for a specified pattern in a column

Answer 9

SQL LIKE Clause

SELECT * FROM Customers
WHERE CustomerName LIKE ‘a%’;

Syntax:

SELECT column1, column2, …
FROM table_name
WHERE columnN LIKE pattern;

Question 10

SQL statements

is used to sort the result-set in ascending or descending order.

Answer 10

SQL ORDER BY Clause

SELECT * FROM Products
ORDER BY Price;

Syntax:

SELECT column1, column2, …
FROM table_name
ORDER BY column1, column2, … ASC|DESC;

Question 11

SQL statements

thhis statement groups rows that have the same values into summary rows

Answer 11

SQL GROUP BY Clause

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country;

Syntax:

SELECT column_name(s)
FROM table_name
WHERE condition
GROUP BY column_name(s)
ORDER BY column_name(s);

Question 12

SQL statements

this function returns the number of rows that matches a specified criterion

Answer 12

SQL COUNT Clause

SELECT COUNT(*)
FROM Products;

Syntax:

SELECT COUNT(column_name)
FROM table_name
WHERE condition;

Question 13

SQL statements

this clause was added to SQL because the WHERE keyword cannot be used with aggregate functions.

Answer 13

SQL HAVING Clause

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5;

Syntax:

SELECT column_name(s)
FROM table_name
WHERE condition
GROUP BY column_name(s)
HAVING condition
ORDER BY column_name(s);

Question 14

SQL statements

this statement is used to create a new table in a database.

Answer 14

SQL CREATE TABLE Statement

CREATE TABLE Persons (
PersonID int,
LastName varchar(255),
FirstName varchar(255),
Address varchar(255),
City varchar(255)
);

Syntax:

CREATE TABLE table_name (
column1 datatype,
column2 datatype,
column3 datatype,
….
);

Question 15

SQL statements

this statement is used to drop an existing table in a database.

Answer 15

SQL DROP TABLE Statement

DROP TABLE Shippers;

Syntax:

DROP TABLE table_name;

Question 16

SQL statements

statement is used to create indexes in tables.

Indexes are used to retrieve data from the database more quickly than otherwise.

Answer 16

SQL CREATE INDEX Statement

CREATE INDEX idx_lastname
ON Persons (LastName);

Syntax:

CREATE INDEX index_name
ON table_name (column1, column2, …);

Question 17

SQL statements

this statement is used to delete an index in a table.

Answer 17

SQL DROP INDEX Statement

Syntax:

ALTER TABLE table_name
DROP INDEX index_name;

Question 18

SQL statements

this command deletes the data inside a table, but not the table itself.

Answer 18

SQL TRUNCATE TABLE Statement

TRUNCATE TABLE Shippers;

Syntax:

TRUNCATE TABLE table_name;

Question 19

SQL statements

this statement is used to add, delete, or modify columns in an existing table.

Answer 19

SQL ALTER TABLE Statement

ALTER TABLE table_name
ADD column_name datatype;

ALTER TABLE table_name
ADD,DROP,MODIFY,RENAME column_name datatype;

Question 20

SQL statements

this statement is used to insert new records in a table.

Answer 20

SQL INSERT INTO Statement

INSERT INTO Customers (CustomerName)
VALUES (‘Tom’);

Syntax:

INSERT INTO table_name (column1, column2, column3, …)
VALUES (value1, value2, value3, …);

Question 21

SQL statements

this statement is used to modify the existing records in a table.

Answer 21

SQL UPDATE Statement

UPDATE Customers
SET ContactName=’Juan’
WHERE Country=’Mexico’;

Syntax:

UPDATE table_name
SET column1 = value1, column2 = value2, …
WHERE condition;

Question 22

SQL statements

this statement is used to delete existing records in a table

Answer 22

SQL DELETE Statement

DELETE FROM Customers WHERE CustomerName=’Alfreds Futterkiste’;

Syntax:

DELETE FROM table_name WHERE condition;

Question 23

SQL statements

this statement is used to create a new SQL database.

Answer 23

SQL CREATE DATABASE Statement

CREATE DATABASE testDB;

Syntax:

CREATE DATABASE databasename;

Question 24

SQL statements

this statement is used to drop an existing SQL database.

Answer 24

SQL DROP DATABASE Statement

DROP DATABASE testDB;

Syntax:

DROP DATABASE databasename;

Question 25

SQL statements

s used to select a database and perform SQL operations into that database.

Answer 25

SQL USE Statement

USE MyDatabase ;

Syntax:

USE database_name;

Question 26

SQL statements

a command that is used for storing changes performed by a transaction

Answer 26

SQL COMMIT Statement

DELETE from Customer where State = ‘Texas’;
COMMIT;

Syntax:

COMMIT;

Question 27

SQL statements

a command that is used for reverting changes performed by a transaction.

Answer 27

SQL ROLLBACK Statement

DELETE from Customer where State = ‘Texas’;
ROLLBACK;

Syntax:

ROLLBACK

Question 28

identification

SQL is followed by a unique set of rules and guidelines called

Answer 28

Syntax.

Question 29

identification

all the statements end with a

Answer 29

semicolon
(;)

Question 30

identification

All the SQL statements start with any of the keywords like

Answer 30

SELECT, INSERT, UPDATE,
DELETE, ALTER, DROP, CREATE, USE, SHOW

Question 31

identification

The most important point to be noted here is that SQL is____which means SELECT and select have same meaning

Answer 31

case insensitive