Mysql Exists
The Tutorial covers on 'Mysql Exists'. The section helps you to understand an example from 'Mysql Exists'.We create a table 'stu' and 'Lib' with required filednames and datatypes respectively.
Create Table Stu
Create Table Stu(Id int,Name Varchar(15)); |
Create Table Lib
Create Table Lib(Id int,libno int); |
Insert Values into Stu
The insert into is used to add the records or rows to the table 'Stu'.
Insert Into Stu values(1,'Ajay'); Insert Into Stu values(2,'Bhanu'); Insert Into Stu values(4,'Rakesh'); Insert Into Stu values(5,'Santosh'); Insert Into Stu values(3,'Komal'); |
Insert Values into Lib
The insert into statement adds the records to the table 'Lib'.
Insert Into Lib values(1,101); Insert Into Lib values(2,102); Insert Into Lib values(4,103); Insert Into Lib values(5,104); Insert Into Lib values(3,105); |
Query for Exists
The Query Exists returns only those id records or rows that exists in table 'stu' and not in table 'lib'.
select id from stu where EXISTS (select id from lib); |
Result
+------+---------+ | Id | Name | +------+---------+ | 1 | Ajay | | 2 | Bhanu | | 4 | Rakesh | | 5 | Santosh | | 3 | Komal | +------+---------+ |