SQL Exercises (3)-New Ket Network

New Ket Network online programming Website: Https://www.nowcoder.com/activity/oj

(SQLite is used by default)

Topic 1:

Get the execution plan for select * FROM Employees

Select *  from Employees;

Topic 2:

Last_Name and first_name of all employees of the Employees table are stitched together as name, separated by a space

CREATE TABLE' Employees ' (' emp_no ')int( One) not NULL, ' birth_date ' date not NULL, ' first_name 'varchar( -) not NULL, ' last_name 'varchar( -) not NULL, ' Gender 'Char(1) not NULL, ' hire_date ' date not NULL,PRIMARY KEY(' Emp_no '));

SELECT last_name| | ' ' ||  from Employees;

"||" To connect strings, MySQL, SQL Server, Oracle and so on are also supported with "+" to connect.

In MySQL, you can do this with the Concat function:

SELECT ' '  from Employees;

You can also use stuff to connect the data in the same column: http://blog.csdn.net/rolamao/article/details/7745972

Topic 3:

Create an actor table that contains information such as the following

is

List	type	null	meaning
actor_id	smallint (5)	NOT NULL	Primary Key ID
First_Name	varchar (45)	NOT NULL	Name
Last_Name	varchar (45)	NOT NULL	Surname
Last_update	Timestamp	NOT NULL	Last update time, default is the current time of the system

CREATE TABLEactor (actor_idsmallint(5)PRIMARY KEY  not NULL, first_namevarchar( $) not NULL, Last_Namevarchar( $) not NULL, Last_updatetimestamp  not NULL DEFAULT(datetime(' Now','localtime')));

Note that the parentheses outside the datetime (' Now ', ' localtime ') must not be omitted.

The CREATE statement is best supplemented by the Create TABLE IF not EXISTS actor (...);

Topic 4:

For the table actor, BULK insert the following data:

actor_id	first_name	last_name	last_update
1	PENELOPE	Guiness	2006-02-15 12:34:33
2	NICK	Wahlberg	2006-02-15 12:34:33

INSERT  intoactor (actor_id, first_name, last_name, last_update)VALUES(1,'PENELOPE','Guiness','2006-02-15 12:34:33'),(2,'NICK','Wahlberg','2006-02-15 12:34:33');

Topic 5:

INSERT OR  into actor (actor_id, first_name, last_name, last_update) VALUES ('3'ED'CHASE')  '2006-02-15 12:34:33');

You can also replace "IGNORE" with "replace".

In MySQL, insert IGNORE into actor (remove "or").

SQL Exercises (3)-New Ket Network