Introduction SQL Syntex

SQL is not case sensitive. Generally SQL keywords are written in uppercase.


SQL statements are dependent on text lines. We can place a single SQL statement on one text line or on multiple.

You can perform most of the action in a database with SQL statements.

SQL depends on relational algebra and tuple relational calculus.

All the SQL statements start with any of the keywords like SELECT, INSERT, UPDATE, DELETE, ALTER, DROP, CREATE, USE, SHOW and all the statements end with a semicolon (;).

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 (arithematic 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 database_name;

SQL COMMIT Statement:

COMMIT;

SQL ROLLBACK Statement:

ROLLBACK;