Create and manage databases and tables in SQL

This SQL script creates and manages databases and tables, including inserting, updating, and deleting records in the 'customers' and 'employees' tables.

Author: Pankaj-Str

Example-File/IT_CWPC45.sql

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+-- Step 1 Create DataBase
+create database cwpc111;
+-- Step 2 select database
+use cwpc111;
+-- Step 3 create a new table 
+create table customers(
+	customerID int primary key,
+    name varchar(100),
+    mobile varchar(100),
+    age int,
+    creditlimit bigint,
+    dob date,
+	bank enum("HDFC","SBI","ICICI")
+);
+-- show tables records
+select * from customers;
+-- insert record into table 
+insert into customers 
+(customerid,name,mobile,age,creditlimit,dob,bank)
+values(1,"nishant","7894562100",14,45000,"2015-04-23","ICICI"),
+(2,"Riya","7894562100",14,45000,"2015-04-23","ICICI"),
+(3,"Neha","7894562100",14,45000,"2015-04-23","HDFC"),
+(4,"Rohan","7894562100",14,45000,"2015-04-23","ICICI");
+
+insert into customers(customerid,name,mobile,age,dob,bank)
+values(10,"nishant","7894562100",14,"2015-04-23","ICICI"); 
+
+-- empty table 
+truncate table customers;
+select * from customers;
+-- delete table
+drop table customers;
+-- check table 
+show tables;
+
+-- find the list of databases 
+show databases;
+-- create a new database
+create database cwpc90;
+-- delete database
+drop database cwpc90;
+-- select database
+ 
+-- create a table 
+create table Employee(
+	emp_id int,
+    name varchar(100),
+    city varchar(100),
+    dob date,
+    salary int,
+    age int,
+    dept enum("hr","sales","it") 
+);
+
+-- show list of tables
+show tables;
+
+-- show table record
+select * from employee;
+
+-- insert record into table 
+
+insert into employee (emp_id,name,city,dob,salary,age,dept)
+value(101,"nishant","mumbai","1990-11-23",45000,32,"sales");
+
+
+
+-- date 5 oct 2026
+
+
+use classicmodels;
+
+show tables;
+
+-- check customers table records 
+select * from customers;
+select customernumber,customername,country,city,creditlimit 
+from customers;
+-- update
+select * from customers where customernumber = 125;
+
+update customers set creditlimit = 10000
+where customernumber = 125; 
+-- delete
+delete from customers where customernumber = 125; 
+-- where
+-- and 
+select * from customers where country = "USA" and creditlimit > 50000;
+-- or
+select * from customers where creditlimit > 100000 and creditlimit < 200000;
+-- count()
+select count(*) from customers 
+where creditlimit > 100000 and creditlimit < 200000;
+
+select customername , country , creditlimit from customers 
+where country = "USA" and creditlimit < 100000;
+
+
+
+
+-- 8 Oct 2026
+create database CWPC_Company;
+use CWPC_Company;
+
+create table employees(
+	employee_id int primary key,
+    name varchar(50),
+    department varchar(50),
+    salary decimal(10,2),
+    city varchar(50),
+    joining_date Date,
+    manager_id int
+);
+
+select * from employees;
+
+
+-- limit
+select * from employees limit 3;
+
+-- order by
+select * from employees order by salary desc limit 5;
+select * from employees order by salary asc limit 5;
+
+-- offset 2 (First 2 row skip)
+select * from employees limit 6 offset 9;
+select * from employees where employee_id > 9 and employee_id < 16;
+
+-- is NULL 
+select * from employees where manager_id is NULL;
+
+-- is not NULL
+select * from employees where manager_id is not NULL;
+
+-- total record not null
+
+select count(*) from employees where manager_id is not NULL;
+
+-- coalesce()
+select name , coalesce(manager_id,0) as manager_id from employees;
+
+select count(*) from employees where Department = "IT";
+
+-- distinct
+select distinct Department from employees;
+-- count() - Department
+select count(distinct Department) from employees;
+
+-- group by
+select Department , count(Department) as total_employee
+from employees group by Department;
+
+select name , salary , salary * 1.10 as new_salary 
+from employees where Department = "IT";
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