class notes for programming

SQL COMMANDS




Prepared By
Sadiya Khan
CONTENTS

1.FUNDAMENTALS OF SQL
2.FILTERING COMMANDS
3.ORDERING COMMANDS

,4.ALIAS
5.AGGREGATE COMMANDS
6.GROUP BY COMMANDS
7.CONDITIONAL STATEMENT
8.JOINS
9.SUBQUERY
10.VIEW & INDEX
11.STRING FUNCTIONS
12.MATHEMATICAL FUNCTIONS
13. DATE-TIME FUNCTIONS
14.PATTERN MATCHING(regex)

15.DATA TYPE CONVERSION FUNCTIONS
DQL(Data Query Language)
To fetch the data from the database
Example: SELECT




DML(Data Manipulation Language)-

, To modify the database objects
Example: INSERT,UPDATE,DELETE




DDL(Data Definition Language)

To create & modify database objects
Example: CREATE,DROP,ALTER,TRUNCATE


1.Fundamentals of SQL

CREATE

CREATE statement is used to create a table



Syntax:
CREATE TABLE ‘’TABLE_NAME’’(
‘’COLUMN1’’ ‘’DATA_TYPE’’ CONSTRAINTS,
‘’COLUMN2’’ ‘’DATA_TYPE’’ CONSTRAINTS,
‘’COLUMN3’’ ‘’DATA_TYPE’’ CONSTRAINTS,
………………………………………………………………..

, ‘’COLUMN N’’ ‘’DATA_TYPE’’ CONSTRAINTS
);



INSERT

INSERT statement is used insert new data
into the table


Syntax:
INSERT INTO
“TABLE_NAME” (COL1, COL2, ……..COL_N)
VALUES (Col_val_1,Col_val_2, ……. Col_val_N);



Import data from file(PostgreSQL)
For csv file
COPY TABLE_NAME(column1, column2,… ) FROM
FILE_PATH DELIMITER ‘ , ’ CSV HEADER;

For txt file
COPY TABLE_NAME(column1, column2,… ) FROM
FILE_PATH DELIMITER ‘ , ’ ;