====== MySQL ======
===== Installing =====
Run this with root permission in your terminal.
apt-get install mysql-server
This will ask you for a password. Type 'password' there.
===== Tasks =====
- Create a 'camp' database
- Create a 'students' table in it with the fields
- Name
- College
- District
- Email
- Age
- Year
- Semester
- Team number
- Branch
- Insert atleast 10 records in it.
- Retrieve all the students whose age is greater than 20
- Retrieve all the students who are in 3rd year
- Retrieve all the students who are in 4th,5th or the 6th team
- Retrieve all the students who are in 2nd year, 2nd semester.
- Retrieve all the students who are in ECE branch.
- Retrieve all the students whose name starts with 'a' and ends with 'd'.
- Create a table called 'favourites' it must have four fields
- Name
- Favourite Session 1
- Favourite Session 2
- Favourite Session 3
- Now, Insert the records with the values of the 'Favourite Sessions' being any session in the camp that you like. For example I like 'python','git','communication-skills' so, I will insert ('ganesh','python','git','communication-skills').
- Retrieve all the students who have 'python' as favourite 1.
- Retrieve all the students who dont have 'databases' as favourite 2.
- Retrieve all the students who have 'git' or 'documentation' as favourite 1.
- Retrieve all the students who have 'python' as favourite 1, 'editors' as favourite 2, and 'databases' as favourite 3.
- Update the email of a student in the 'students' table to 'xyz@google.com' where the name is 'john' (Create a row with name = john for this.)
- Find the number of students in students table.
===== Reference =====
=== Create ===
Replace tablename with your table's name, the fieild1,field2 with your field's names' and the type1,type2 with your respective types.
CREATE table tablename (field1 type1,field2 type2);
=== Select ===
== Selecting all columns ==
SELECT * from tablename;
== Selecting some columns ==
SELECT field1,field2 from tablename;
== Selecting with conditions ==
SELECT * from tablename where field == value;
== Supported Conditions ==
field > number (Eg : age > 10 )
field < number
field == number
field >= number
field <= number
field in (v1,v2,v3) (Eg: name in ('ganesh','divya'))
field not n (v1,v2,v3)
field like '%' (Eg: name like 'g%' [Matches all names starting with g] or name like '%g' [matches all names ending with g])
field not like '%'
== Multiple constraints ==
We can use and,or in SQL to support multiple constraints
SELECT * from tablename where n > 10 and b < 20; # Executes only if both a > 10 and b < 20
SELECT * from tablename where n > 10 or b < 20; # Executes if any is true
== Getting Count==
SELECT count(*) from tablename;
=== Update ===
UPDATE tablename set field = value where field2 = value2;
Multiple constraints apply here also.
=== Insert ===
INSERT INTO tablename values ( value1, value2, value3 );