SQL (structured query language)

• Sql access and manipulate database

•       Mostly use commands we short in a 4 type for understanding

•       Table

•       CREATE

•       DROP

•       ALTER

•       Records

•       INSERT

•       UPDATE

•       DELETE

•       Permission

•       GRANT

•       REVOKE

•       Query

•       SELECT

Data types

•       In SQL divided in to 6 type

•       CHAR

•       Maximum store 225 characters.

•       Its store character string fixed length.

•       Ex. Name CHAR(100)

•       VARCHAR/VARCHAR2

•       Its store alphanumeric values fixed length.

•       Maximum store 4000 characters.

•       DATE

•       Its store date & time

•       NUMBER

•       Its store numbers integer & floating_point number.

•       Maximum length is 38 characters  long

•       Syntax NUMBER(p,s) s for total size & p is after point how many number is display

•       Ex. Balance NUMBER(2,4)

20.22

•       LONG

•       Its store variable character string up to 2GB

•       LONG can store binary data in ASCII format

•       RAW/LONG RAW

•       RAW/LONG RAW story binary data picture or image

•       Its up to 2GB