SQL SELECT Statement – Query, Syntax, Condition, Example

SQL SELECT Statement is explained with definition, syntax, query, & example. It is also given with different conditions like WHERE, IN, LIMIT, ORDER BY, GROUP BY, HAVING. Once, you read complete this tutorial, you definitely select data from specified/all columns of a table.

SQL SELECT Statement

Definition –  SQL SELECT statement retrieves existing data from specified columns of a table.

SELECT Syntax

You can select data from a table with the help of the following syntax

Syntax –

SELECT column1_name, column2_name, column3_name,...
FROM table_name;

Important Points –

• You can write a SELECT statement in Uppercase or lowercase.
• Column Names must be separated by a comma
• Before executing the SELECT query, you must create a SQL database & table
• Always declare column names without quotation.
• You can execute the SELECT query multiple times.
• You can skip the column name from the SELECT query if you need to select values from all column of a table

SELECT Example

Now, You will earn to execute the SELECT statement with the following table. This table is created for showing an example. once you understand it. you can easily select data from your own table of the project.

Table Name – students

This table will be joined to subjects table based on a common column  subject_id.

Table Name – students

SQL SELECT Data From All Columns

If you need to select data from all columns of table, you can use strict * symbole instead of column name.

Syntax –

SELECT * FROM table_name;

Example –

You can select  data from all column of students table using the follwing query

Query –

SELECT * FROM students

SQL SELECT Data FROM Specified Column

You can also select data from specified column of table. Let’s understand it through the following example

Example – 1

If you want to select only student_name from students table then use the follwing query

Query – 

SELECT student_name 
FROM students;

Example – 2

If you want to select only student_name & city from students table then use the following query

Query –

SELECT student_name, city 
FROM students;

SQL SELECT Conditions

Now, Let’s go to learn the SELECT statement with the following different conditions.

SELECT WHERE

You can use SELECT statement with WHERE clause if you have to retrieve data on a specified condition

Syntax –

SELECT column1_name, column2_name,...
FROM table_name
WHERE condition;

Note – You must declare WHERE condition after the table name.

Example –

If you have to select only a male student name then you will have to use the WHERE condition in the SELECT query

Query –

SELECT student_name 
FROM students
WHERE gender='Female';

Output –

SELECT IN

You can use SELECT statement with IN operator if you have to retrieve data based on multiple conditions

Syntax –

SELECT column1_name, column2_name,...
FROM table_name
IN (column_value1, column_value2,...);

Note – You must declare IN operator after the table name.

Example –

If you have to select cities and student names who belongs to  Jaipur or Noida then you will have to use IN operator in the SELECT query

Query –

SELECT student_name, city
FROM students
IN ('Jaipur', Noida)

Output –

SELECT LIMIT

You can use a SELECT statement with the LIMIT condition if you have to retrieve data with only a limited number of records.

Syntax –

SELECT column1_name, column2_name,...
FROM table_name
LIMIT number;

Note – You must declare LIMIT after the table name.

Example –

If you have only 4 student names then you will have to use LIMIT in the SELECT query

Query –

SELECT student_name
FROM students
LIMIT 4;

Output –

SELECT ORDER BY

You can use a SELECT statement with an ORDER BY clause if you have to retrieve data in descending or ascending order.

Syntax –

SELECT column1_name, column2_name,...
FROM table_name
ORDER BY column_name DESC|ASC;

Note – You must declare the ORDER BY clause after the table name.

Example –

If you have to select only student names in descending order then you will have to use ORDER BY clause in SELECT query.

Query –

SELECT student_name 
FROM students
ORDER BY student_name DESC;

Output –

SELECT GROUP BY

You can use a SELECT statement with a GROUP BY clause if you have to retrieve data based on a group of the same values.

Syntax –

SELECT column1_name, column2_name,...
FROM table_name
GROUP BY column1_name, column2_name,...

Note – You must declare the GROUP BY clause after the table name.

Example –

If you have to select the city and the total number of students from a particular city then you will have to use the GROUP BY clause in the SELECT query.

Query –

SELECT city, count(student_name) 
FROM students
GROUP BY city;

Output –

SELECT HAVING

You can use a SELECT statement with a HAVING BY clause if you have to retrieve data based on groups of the same values.

Syntax –

SELECT column1_name, column2_name,...
FROM table_name
HAVING condition

Note – You must declare the HAVING clause after the table name.

Example –

If you need to know the names of the city that has less than 2 students.

Query –

SELECT city, count(student_name) 
FROM students
GROUP BY city;
HAVING count(student_name)<2;

Output –

How to Execute SQL SELECT Statement

you have to run the following steps to execute SQL SELECT Statement–

• First of all, Install MySQL Server Package
• Create a MySQL Database like mydb
• Now, Create a table like students
• Insert data into the created table
• Write a SELECT query command to retrieve data from a table.

mysql>CREATE DATABASE mydb;
mysql>USE mydb;
mysql>CREATE TABLE students ( 
student_name varchar(50),
gender varchar(20), 
city varchar(100)
);
mysql>INSERT INTO students
( student_name, gender, city) VALUES 
( 'Navneet Singh', 'Male', 'Panjab'),
('Mr Tommy', 'Male', 'Jaipur'), 
( 'Mrs Monika', 'Female', 'Patna'), 
('Mrs Maliska', 'Female', 'Patna'),
( 'Ravish Kumar', 'Male', 'New Delhi'),
('Sanjay Agarwal', 'Male', 'Mumbai'),
('Babita Mishra', 'Female', 'New Delhi'), 
('Neil Patel', 'Male', 'Noida'), 
('Pushpa Yadav', 'Female', 'Patna'),
('Aryan Singh', 'Male', 'Noida'),
('Javed Hassan', 'Male', 'Jaipur');
mysql>SELECT student_name, city FROM students;

Tutorial Suggestion –

You have learned to select values from a table using the SELECT statement. Now you can easily implement it with different & complex queries.

If you need to ask questions related to SQL, Kindly ask me through the comment box. Even you should share it with your friends.