MySQL list of clauses; Through this tutorial, i am going to show you MySQL clauses like DISTINCT, FROM, GROUP BY, ORDER BY, HAVING, WHERE with the help of examples.
List of MySQL Clauses
Let’s see following MySQL clauses with the help of examples; as follows:
- WHERE Clause MySQL
- DISTINCT Clause MySQL
- FROM Clause MySQL
- ORDER BY Clause MySQL
- GROUP BY Clause MySQL
- HAVING Clause MySQL
WHERE Clause MySQL
In MySQL WHERE Clause commonly used with SELECT statement, INSERT INTO statement, UPDATE statment and DELETE statement. Because it filter the record from database table.
Syntax MySQL WHERE Clause; as follows;
WHERE conditions;
Example 1 – MySQL WHERE Clause
SELECT * FROM users WHERE email = '[email protected]';
The above statement selects all the records from the database table users, where the value of the email column is equal to [email protected].
Example 2 – MySQL WHERE Clause with AND
SELECT * FROM users WHERE first_name = 'tut' AND id < 1000;
The above statement selects all the records from the database table users, where the value of the name column is equal to tuts and it’s id less than 1000.
MySQL DISTINCT Clause
In MySQL DISTINCT Clause can be used within an MySQL statement to remove duplicate rows from the databse table and retrive only the unique data.
Syntax of MySQL DISTINCT Clause
SELECT DISTINCT column1,column2 ….columnN
FROM tables
[WHERE conditions];
Example 1 – Mysql DISTINCT Clause
SELECT DISTINCT name FROM users;
This above query using the DISTINCT keyword to removed the duplicates data. Therefore, it will contain a unique value.
MySQL FROM Clause
The MySQL FROM Clause can be used to select some records from the database table. Using the JOIN Clause, it can also be used to obtain records from several database tables.
Syntax of MySQL FROM Clause
FROM table1 [ { INNER JOIN | LEFT [OUTER] JOIN | RIGHT [OUTER] JOIN } table2 ON table1.column1 = table2.column1 ]
Example 1 – FROM Clause MySQL
SELECT * FROM users WHERE id = 50;
The above query selects all the records from the database table users, where the id value of the id column is equal to 50.
ORDER BY MySQL Clause
The MYSQL ORDER BY Clause can be used to sort records in ascending or descending order and to sort records by one or more database table fields.
Syntax of ORDER BY MySQL Clause
SELECT column1,column2 FROM tables [WHERE conditions] ORDER BY column_name [ ASC | DESC ];
Example 1 – ORDER BY Clause MySQL
SELECT * FROM users WHERE country = 'USA' ORDER BY first_name ASC;
The above query selects all records from the users database table, then orders them by the first_name field in ascending order.
SELECT * FROM users WHERE country = 'USA' ORDER BY first_name DESC;
The above query selects all records from the users database table, then orders them by the first_name field in descending order.
GROUP BY Clause MySQL
The GROUP BY clause groups the returned record set by one or more columns. You specify which columns the result set is grouped by.
Syntax of GROUP BY Clause MySQL
SELECT column1, column2, … column_n, aggregate_function (column) FROM tables [WHERE conditions] GROUP BY column1, column2, … column_n;
Example 1 – MySQL GROUP BY Clause
SELECT address, COUNT(*) FROM users GROUP BY address;
The above query selects all records from the users database table, then groups them by the address field.
HAVING Clause MySQL
MySQL HAVING Clause is used with GROUP BY clause. It always returns the rows where condition is TRUE.
Syntax of MySQL HAVING Clause
SELECT column1, column2, … column_n,
aggregate_function (column)
FROM tables
[WHERE conditions]
GROUP BY column1, column2, … column_n
HAVING condition;
Example 1 – HAVING Clause MySQL
SELECT op_name, SUM(working_hours) AS "totalWorking"
FROM operators
GROUP BY op_name
HAVING SUM(working_hours) > 7;
The above query selects all records from the users database table, then return the emp_name and sum of their working hours.
Conclusion
In this MySQL tutorial point – we have demonstrated about the MySQL clause with its syntax and example.