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find out database
command=> show databases;

create database:
syntax=> create database database_name;
create database second;

select working database
syntax:-use database_name;
=>use second

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create table:
syntax:
create table table_name(
      column1 datatype,
      column2  datatype,
      column3 datatype,
       -
      column3 datatype
       );

exa:-   create table Student(
           rno int, 
           name varchar(20), 
           address varchar(20),
          marks int, 
          gender char(1));

checking table:
show tables_name;
=> show Student;


for showing table structure:
syntax:desc tablename;
exa :-desc Student;

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insrt data into table:
seuence is manadatory.
number of column =number of values
1- insert into tablename values(value1,value2,-----valueN);
exa:- insert into Student values(1,'nikki','pune',56,'male');

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--sequence is manadory for column we given in insert stament
count of column specify into insert =number of values

no value for any column.
2.- insert into Tablename(column1,column2-----columnN) values(value1,value2,-----valueN);

ex:- insert into Student(rno,name,marks,gender) values(2,'nikita',70,'F');

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multiple value insert at one time
syntax:- insert into tablename values(value1,value2,-----valueN),(value1,value2,-----valueN)-----(n);
exam:- insert into Student values(3,'ram','satara',67,'m'),
                                 (4,'anita','nagpur',89,'F'),
                                  (5,'jashu','nagpur',90,'M');



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fetch all record from tables:-
syntax:-
selct * from tablename;
exam:-select * from Student;

fetch select column from table;
ex;- select name,marks from Student;
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Contraints in sql:
contraints is use for to specify rules for the data in table.
1. NOT NULL:-ensure that the column cannot have a null values:
2.UNIQUE:-ensure that all values in a column are differents.
3.CHECK:-Ensures that the values in a columns satisfies a given specific condition.
4.DEFAULT:-set a default value if value is not specified for a column.
5.PRIMARY KEY:-ensure that  the values of column is NOT NULL and UNIQUE.


syntax:-
create table table_name(
           column1 datatype contraint,
           column2 datatype contraint,
             -
             -
           columnN datatype contraint
    );

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Drop command:-
for database:
 is used for delete the existing sql database.
syntax:- drop database Database_name
example:- drop database demo1;

for table:
drop table command is used for the table structure delete from database.

syntax:- drop table table_name
example:- drop table student;

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truncate command:
is used for  delete the data from tables.
it is used for empty table.

syntax:-tuncate table tablename;
exa;- truncate table customer;

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Difference between drop and trucate:
Drop :-1.Drop command is use for remove table defination /table structure from database.
       2. table does not exist in databse.


Truncate:-1.truncate command is used for delete all rows from tables.structure remain same.
          2.table is exist in databse.show empty table.

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Assignment:-
Create Customer table.
custid primary key,
name unique,
address not null
age age>18
gmail abc@g.com

insert minimum 10 records


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