Escritura de Sentencias SQL SELECT Básicas
CAPITULO I
En este capitulo se tratara todo lo relacionado a las sentencias SQL, sus funciones y ejemplos, los temas a tratar son:
| Sentencias Basicas | SELECT *|{[DISTINCT] column|expression [alias],...} FROM table |
| Seleccion columnas Especificas | SELECT department_id, location_id FROM departments; |
| Operadores Aritmeticos | SELECT last_name, salary, salary + 300 FROM employees; |
| Definición de Valor Nulo | SELECT last_name, job_id, salary, commission_pct FROM employees; |
| Uso de Alias en Columna | SELECT last_name AS name, commission_pct comm FROM employees; |
| Operador de Concatenación | SELECT last_name||job_id AS "Employees" FROM employees; |
| Eliminación de Filas Duplicadas | SELECT DISTINCT department_id FROM employees; |
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EJERCICIOS PRACTICOS
Apellidos de los empleados que ganan mas de 12000.
select last_name, salary
from employees
where salary > 12000;
Muestra apellidos y departamentos de los empleados que sean con codigo igual a 176.
select last_name, department_id
from employees
where employee_id = 176;
select last_name, salary
from employees
where salary <= 5000 or salary >= 12000;
where salary not between 5000 and 12000;
select last_name, job_id, hire_date
from employees
where hire_date between ’20/02/98’ and ’01/03/98’
order by hire_date;
Fecha actual
select sysdate from dual;
select last_name as nombre , department_id as plata
from employees
where department_id in (20,50)
order by first_name;
select last_name as nombre , salary as plata
from employees
where (salary <= 5000 or salary >= 12000) and (department_id in (20,50));
select last_name, hire_date
from employees
where hire_date LIKE ’%94’;
select last_name, job_id
from employees
where manager_id is null;
select last_name, salary , commission_pct
from employees
where commission_pct is not null
order by salary desc , commission_pct desc;
select first_name, last_name, salary , commission_pct
from employees
where last_name like ’__a%’;
select last_name, salary , commission_pct
from employees
where last_name like ’%a%’ and last_name like ’__e%’;
select last_name, job_id, salary
from employees
where job_id IN (’ST_CLERK’,’SA_REP’) and salary not in (2500, 3500, 7000) ;
select commission_pct, last_name as nombre , salary as plata
from employees
where commission_pct = 0.2;
2 comentarios
Jeimy -
What is you question?
Jordan 11 -