DATABASE NAME: testing
TABLE NAMES: area , category , subcat
VIEW NAME: currentc
FOR STORED PROCEDURE DATABASE NAME: proc
FOR TRIGGER DATABASE NAME: trig
INSERT QUERY:
insert into test1 values (6,’sd’,’cd’,11);
insert into category values (1,52,12,10)
SELECT QUERY:
select * from category
select count(*) as number from table_name where field = ‘value’;
// it will return number of rows..
select sum(value) from subcat;
SELECT DISTINCT QUERY:
select distinct name from subcat
WHERE CLAUSE:
select * from subcat where cost1 > 80
select * from subcat where name = ‘c2’
AND CLAUSE:
select * from subcat where name = ‘c2’ and cost1 = 85
OR CLAUSE:
select * from subcat where name = ‘c2’ or cost1 = 85
ORDER BY:
select * from subcat order by cost1
select * from subcat order by cost1 desc
UPDATE QUERY:
update subcat set cost1 = 52, name = ‘c4’ where id2 = 3
DELETE QUERY:
delete from subcat where cost1 = 52
delete from category; delete all the data
LIMIT QUERY:
select * from area limit 2 ; to display records in limited range ; always use wildcard with limit query
LIKE QUERY: like query is an alias for where
select *from area where lname like ‘ v% ‘; select all with starting with v
select *from area where lname like ‘ %v’ select all with ending v
select * from area where fname like ‘_a’ // start with any character followed by a // _ use for any character
select * from area where fname like ‘[as]%’ // for character set
IN CLAUSE:
select * from area where fname in (‘s’,’sa’);
BETWEEN QUERY:
select * from area where lname between ‘v’ and ‘vo’ // for character
select * from area where age between 21 and 26 // for number
ALIASES:
select a.lname, c.cost from area as a, category as c where a.id = 2 // use for shortname of tables using as
UNION:
select name from category union select name from subcat // u can use with different coiumn name also
select name from category union all select name from subcat
SELECT INTO:
select * into table ssubcat from subcat; // to create another same copy of table
select * into table ssubcat in ‘newdb.mdb’ from subcat // to create another same copy of table in new db
ALTER QUERY
alter table `testing`.`category` add column’ ‘name’ VARCHAR(45) after ‘quantity’;
alter table area drop index gender
ALTER TABLE `testing`.`subcat` ADD COLUMN `name` VARCHAR(50) AFTER `value`;
nsert into subcat values (4,95,55,’cat4′)
rename table test1 to area;
CRREATE QUERY:
create database testing
create table ‘testing’ , ‘category’ (
‘id1’ int auto_increment,
‘cost’ varchar(45),
‘value’ varchar(45),
‘quantity’ varchar(45),
primary key(‘id1’)
)
unique key can be more then 1
primary key can’t be more then 1
foriegn key use to link b/w to tables // in one table pk will be foreign key for another table
INDEX:
create index sn on subcat (name) // u can’t see index just useful for fast searching
DROP QUERY:
drop table area; // u can also use drop for dropping database and also for index
VIEW: // its one kind of virtual table use to store data
to create:
create view Currentc as select cost1,name from subcat where id2 = 2
to display:
select * from Currentc
to drop:
drop view Currentc
DATE : format is (yy or yyyy- mm – day)
select datediff(‘2008-11-20′,’2008-11-15’) as diffate // O/P = 5 //
JOIN QUERY: // to use it one column must common b/w to tables and use on keyword instead of where. // first table will be left and second will be right
select category.cost, subcat.cost1 from category join subcat on category.name=subcat.name; // join will work same as inner join // most time use with on keyword
select category.cost, subcat.cost1 from category left join subcat on category.name=subcat.name;
select category.cost, subcat.cost1 from category right join subcat on category.name=subcat.name;
AGGREGATE FUNCTIONS:
select avg(value) from subcat // to calculate average
select first(name) from subcat // return first
select last(name) from subcat
select max(cost1) from subcat
select min(cost1) from subcat
select sum(cost1) from subcat
GROUP BY QUERY:
select cost1,sum(cost1) from subcat group by name;
TRIGGERS:
//to use define or then to use it anywhere use @ keyword // @ this keyword is used for accessing variable
create table account (acct_num INT, amount DECIMAL(10,2)); // for creating table
create trigger ins_sum before insert on account for each row set @sum = @sum + NEW.amount; // mysql doesnt support multiple triggers
after creting trigger for checking it do……………
set @sum = 0;
insert into account values(138,16.98),(148,2937.50),(98,-200.00);
select @sum as ‘Total amount inserted’;
//for dropping:
drop trigger test.ins_sum;
//for getting list of triggers
Show Triggers From databse_name
STORED PROCEDURE:
//to declaer,display,set any variable…
DECLARE var1 varchar(15);
select count(*) into var1 from test1;
select @var1;
//to declaer,display,set any variable.
SET @a = 10;
SELECT @a;
//how to pass table name and column name as argument see here
CREATE PROCEDURE varstm(IN test1 CHAR(64), IN age CHAR(64)
BEGIN
SET @s = CONCAT(‘SELECT AVG(‘ , age , ‘) FROM ‘ , test1);
#select @s;
PREPARE stmt FROM @s;
EXECUTE stmt;
//we use cursor for sql query statment with stored procedure and also we can save that value to particular variable
DELIMITER $$
DROP PROCEDURE IF EXISTS `proc`.`curs` $$
CREATE PROCEDURE `proc`.`curs` (in id int , out var varchar(10)) //here id is work as input variable and var work as output variable
BEGIN
DECLARE cur1 CURSOR FOR SELECT stu_name from stu_table where stu_id =id;
OPEN cur1;
Fetch cur1 into var;
close cur1;
//to call cursor and display value we use
call curdemo(2, name);
select @name;
//to create it
create procedure p1
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