SQL Syntax

By | July 19, 2020

Every SQL RDBMS follow a similar set of rules and syntax which are known as queries and statements. While writing the queries in SQL we have to take care of syntax, if we write a query with invalid syntax then the SQL throw some errors.

Every SQL query or statement starts with a command like SELECT, INSERT, UPDATE, DELETE, ALTER, DROP, CREATE, USE, SHOW, etc. and ends with a semicolon (;), if we do not put a semicolon the query will not execute.

Vamware

SQL commands are insensitive in nature which mean SELECT and select have the same meaning, and this case-insensitive concept also applies on the database and tables, if there is a Database with name Music then you cannot create another database with name MusiC, or music, or MuSic.

SQL Syntax for various commands

1. SQL SELECT Command

SELECT Field_name_1, Field_name_2
FROM table_name;
here SELECT and FROM are SQL commands.

2. SQL DISTINCT Clause:

SELECT DISTINCT Field_name_1, Field_name_2
FROM table_name;

3. SQL WHERE Statement:

SELECT Field_name_1, Field_name_2
FROM table_name
WHERE Conditoin1 operator Condition2;

4. SQL AND/OR Operator

SELECT Field_name_1, Field_name_2
FROM   table_name
WHERE  CONDITION-1 {AND|OR} CONDITION-2;

5. SQL IN Operator

SELECT Field_name_1, Field_name_2
FROM   table_name
WHERE  Field_name IN (val1, val2, val3,…);

6. SQL BETWEEN Statement

SELECT Field_name_1, Field_name_2
FROM   table_name
WHERE  Field_name BETWEEN val1 AND val2;

7. SQL LIKE Statement

SELECT Field_name_1, Field_name_2
FROM   table_name
WHERE  Field_name LIKE { like_patterns };

8. SQL ORDER BY Statement:

SELECT Field_name_1, Field_name_2
FROM   table_name
WHERE  CONDITION
ORDER BY Field_name {ASC|DESC};

9. SQL GROUP BY Statement:

SELECT AVG(Field_name_1)
FROM   table_name
WHERE  CONDITION
GROUP BY Field_name;

10. SQL COUNT Function:

SELECT COUNT(Field_name)
FROM   table_name
WHERE  condition;

11. SQL HAVING Statement:

SELECT AVG(Field_Name)
FROM   table_name
WHERE  condition
GROUP BY Field_name
HAVING (condition);

12. SQL CREATE TABLE Statement

CREATE TABLE table_name(
field_name_1 datatype,
field_name_2 datatype,
field_neme_3 datatype,
.....
field_name_N datatype,
);

13. SQL DROP TABLE Statement

DROP TABLE table_name;

14. SQL CREATE INDEX Statement

CREATE UNIQUE INDEX index_name
ON table_name ( Field_name_1, Field_name_2, ……. field_name_n);

15. SQL DROP INDEX Statement

ALTER TABLE table_name
DROP INDEX index_name;

16. SQL DESC Statement

DESC table_name;

17. SQL TRUNCATE TABLE Statement

TRUNCATE TABLE table_name;

18. SQL ALTER TABLE Statement

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

19. SQL Rename TABLE Syntax:

ALTER TABLE table_name RENAME TO new_table_name;

20. SQL INSERT INTO Statement

INSERT INTO table_name( Field_name_1, Field_name_2,…..Field_name_n)
VALUES ( val1, val2....valN);

21. SQL UPDATE Statement

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

22. SQL DELETE Statement

DELETE FROM table_name
WHERE  {condition};

23. SQL CREATE DATABASE Statement

CREATE DATABASE database_name;

24. SQL DROP DATABASE Statement

DROP DATABASE database_name;

25. SQL USE Statement

USE database_name;

26. SQL COMMIT Statement

COMMIT;

27. SQL ROLLBACK Statement

ROLLBACK;

SQL Syntax Quick Summary

  • SQL statements are known as SQL queries.
  • Each SQL query contains some SQL commands.
  • SQL commands are Case insensitive.
  • Every SQL query ends with a semicolon.
  • If you pass an invalid SQL query then the SQL engine would throw an error.

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