SQL Syntax

Learning Objective: In this tutorial, you will learn about SQL Syntax.

SQL language follows some set of rules and guidelines called syntax. The aim of this tutorial is to give you basic idea about the SQL syntax.

All the SQL statements start with any of the keywords like SELECT, DELETE, UPDATE, ALTER, DROP, etc. and each statement ends with a semicolon (;).

SQL Syntax Important Points

1. SQL statement are case insensitive that means in SQL, SELECT and select both are same. Whereas, MySQL makes difference in table names. So, while working in MySQL, you need to keep this in mind and have to provide exact name as they are in database.
2. Generally, SQL keywords are written in uppercase.
3. SQL syntax is derived from the relational algebra and tuple relational calculus.
4. Each SQL statement ends with semicolon (;). Semicolon are generally used to separate two SQL statement from each other where more than one statement is used.

SQL Syntax Example

Following are the most commonly used SQL syntaxes.

All the SQL syntaxes are mentioned here are tested in MySQL database.

SQL SELECT Statement

SELECT column1, column2....columnN
FROM   table_name;

SQL DISTINCT Clause

SELECT DISTINCT column1, column2....columnN
FROM   table_name;

SQL WHERE Clause

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION;

SQL AND/OR Clause

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION-1 {AND|OR} CONDITION-2;

SQL IN Clause

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name IN (val-1, val-2,...val-N);

SQL BETWEEN Clause

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name BETWEEN val-1 AND val-2;

SQL LIKE Clause

SELECT column1, column2....columnN
FROM   table_name
WHERE  column_name LIKE { PATTERN };

SQL ORDER BY Clause

SELECT column1, column2....columnN
FROM   table_name
WHERE  CONDITION
ORDER BY column_name {ASC|DESC};

SQL GROUP BY Clause

SELECT SUM(column_name)
FROM   table_name
WHERE  CONDITION
GROUP BY column_name;

SQL COUNT Clause

SELECT COUNT(column_name)
FROM   table_name
WHERE  CONDITION;

SQL HAVING Clause

SELECT SUM(column_name)
FROM   table_name
WHERE  CONDITION
GROUP BY column_name
HAVING (arithmetic function condition);

SQL CREATE TABLE Statement

CREATE TABLE table_name(
column1 datatype,
column2 datatype,
column3 datatype,
.....
columnN datatype,
PRIMARY KEY( one or more columns )
);

SQL DROP TABLE Statement

DROP TABLE table_name;

SQL CREATE INDEX Statement

CREATE UNIQUE INDEX index_name
ON table_name ( column1, column2,...columnN);

SQL DROP INDEX Statement

ALTER TABLE table_name
DROP INDEX index_name;

SQL DESC Statement

DESC table_name;

SQL TRUNCATE TABLE Statement

TRUNCATE TABLE table_name;

SQL ALTER TABLE Statement

ALTER TABLE table_name {ADD|DROP|MODIFY} column_name {data_ype};

SQL ALTER TABLE Statement (Rename)

ALTER TABLE table_name RENAME TO new_table_name;

SQL INSERT INTO Statement

INSERT INTO table_name( column1, column2....columnN)
VALUES ( value1, value2....valueN);

SQL UPDATE Statement

UPDATE table_name
SET column1 = value1, column2 = value2....columnN=valueN
[ WHERE  CONDITION ];

SQL DELETE Statement

DELETE FROM table_name
WHERE  {CONDITION};

SQL CREATE DATABASE Statement

CREATE DATABASE database_name;

SQL DROP DATABASE Statement

DROP DATABASE database_name;

SQL USE Statement

USE database_name;

SQL COMMIT Statement

COMMIT;

SQL ROLLBACK Statement

ROLLBACK;

Summary: In this tutorial, you have got some basic idea about SQL Syntax.