tables and sql basics
DESCRIPTION
it is very basic introduction to SQL statements, using access syntaxTRANSCRIPT
TABLES AND SQL
Controlling Tables Programmatically
By: Amit Kumar Singh
Tables
• 2 Dimensional matrix• Unique name
SQL
• Structured Query Language • ANSI standard computer language
• Allows you to access a database
• Execute queries, retrieve, insert, delete, update records
• Freedom from intricacy & details of database softwares.
• EASY TO LEARN
Creating Tables
• CREATE TABLE table_name
( column_name1 data_type, column_name2 data_type, ....... ) ;
Example, • CREATE TABLE Person (
LastName varchar(30), FirstName varchar, Address varchar, Age int(3) ) ;
• Create Table tbldemo
( Name text(30),
Age integer,
Gender text(1)
);• Data type depends on the Database management software you are using
SQL ALTER TABLE
• ALTER TABLE table_name ADD COLUMN_name datatype
• ALTER TABLE table_name DROP COLUMN column_name
• Example,
• ALTER TABLE tbldemo ADD COLUMN date_of_birth datetime
• ALTER TABLE tbldemo DROP COLUMN marks;
SQL INSERT
• INSERT INTO table_name VALUES (value1, value2,....)
• INSERT INTO table_name (column_name1,column_name2,...)VALUES(value1, value2,....)
• Example,
• INSERT INTO tbldemo VALUES ('Amit', 22, 'm', #8/22/1982#, 27474017);
• INSERT INTO tbldemo ( Name, Age, Gender, date_of_birth )
VALUES ('Preeti', 22, 'f', #2/18/1982#);
SQL SELECT
• SELECT column_name(s) FROM table_name
• SELECT * FROM table_name
• SELECT * INTO new_table_name FROM original_table_name
• SELECT column_name(s) FROM table_name WHERE condition
• Example,
• SELECT Name FROM tbldemo WHERE GENDER='f';
SQL UPDATE
• UPDATE table_nameSET column_name=new_value[, column_name=new_value]WHERE column_name=some_value ;
• Example,
• UPDATE tbldemo SET phone_no = 22523250 WHERE name='ShriRam';
SQL DELETE
• DELETE FROM table_name WHERE condition
• DELETE FROM table_name (Note: Deletes the entire table!!)
• Example,• DELETE FROM tbldemo WHERE Gender='f';
SQL DROP TABLE
• DROP TABLE table_name
• Example,
• DROP TABLE tbldemo;
More SQL…
• http://www.w3schools.com/sql/default.asp
• http://w3.one.net/~jhoffman/sqltut.htm