×
Night mode
Sign up
Login
Results: 1578
Notes
  • Newest first
  • Oldest first
  • Newest first(All)
  • Oldest first(All)
IN
Selects all students that has one of the following last names 
გოგია
გაგუა
გოგუა
SELECT *
FROM students
WHERE last_name IN ('გოგია', 'გაგუა', 'გოგუა')
Filtering the result using 
IN
with sub-query:
SELECT
    *
FROM
    students
WHERE
    last_name IN(
        SELECT
            last_name
        FROM
            students
        WHERE
            id <= 5
    )
Alternative of the query using 
=
operator:
SELECT *
FROM students
WHERE last_name = 'გოგია' 
OR last_name = 'გაგუა'
OR last_name = 'გოგუა'
by Valeri Tandilashvili
5 years ago
0
MySQL
IN
1
Set column at the top
Makes the column first - sets it at the top
ALTER TABLE note
CHANGE COLUMN title title VARCHAR(210) FIRST
The same thing using 
MODIFY
ALTER TABLE note
MODIFY COLUMN title VARCHAR(210) FIRST
by Valeri Tandilashvili
5 years ago
0
MySQL
ALTER TABLE
1
Changes column position in a table 
ALTER TABLE note
CHANGE COLUMN title title VARCHAR(210) AFTER author_id
Another way to do the same thing is to use 
MODIFY
instead of 
CHANGE
ALTER TABLE note
MODIFY COLUMN title VARCHAR(210) AFTER description
by Valeri Tandilashvili
5 years ago
0
MySQL
ALTER TABLE
Full MySQL Course for Beginners
1
Deletes specified column from a table
Deletes column 
title
from table 
note
ALTER TABLE note 
DROP COLUMN title;
COLUMN
is optional. The following query is alternative to the first one:
ALTER TABLE note 
DROP title;
by Valeri Tandilashvili
5 years ago
0
MySQL
ALTER TABLE
Full MySQL Course for Beginners
1
Rename column
Renames the column 
name
to 
title
ALTER TABLE note CHANGE name title VARCHAR(210)
by Valeri Tandilashvili
5 years ago
0
MySQL
ALTER TABLE
Full MySQL Course for Beginners
1
Change column type
Changes the column type to 
VARCHAR(200)
ALTER TABLE note
MODIFY COLUMN title VARCHAR(200) NOT NULL;
by Valeri Tandilashvili
5 years ago
0
MySQL
ALTER TABLE
Full MySQL Course for Beginners
1
Add column to an existing table
Adds column 
author_id
to the table 
note
after 
title
column
ALTER TABLE note
ADD COLUMN author_id int not null default 0 AFTER title;
by Valeri Tandilashvili
5 years ago
0
MySQL
ALTER TABLE
Full MySQL Course for Beginners
1
Change AUTO_INCREMENT value
Changes 
AUTO_INCREMENT
value for 
note
table to 
100000
ALTER TABLE note
AUTO_INCREMENT = 100000;
by Valeri Tandilashvili
5 years ago
0
MySQL
ALTER TABLE
AUTO_INCREMENT
Full MySQL Course for Beginners
1
Adding AUTO_INCREMENT to any varchar column
Adding 
AUTO_INCREMENT
to any 
varchar
column first requires the column to be converted into 
int
CREATE TABLE note (
    title varchar(50),
    description varchar(50),
    PRIMARY KEY(title)
);
INSERT INTO `note` (`title`, `description`) VALUES ('first', 'value'), ('second', 'value');
Let's add 
AUTO_INCREMENT
to 
title
column. We are not able to add 
AUTO_INCREMENT
without changing it's type to 
int
ALTER TABLE note MODIFY title int NOT NULL AUTO_INCREMENT;
Note: In such cases If the table contains rows with string values, (for 
AUTO INCREMENT
field) the string values will be replaced with numbers starting with 1
by Valeri Tandilashvili
5 years ago
0
MySQL
AUTO_INCREMENT
1
Add AUTO_INCREMENT to an existing column
Let's first create 
note
table without any column to have 
AUTO_INCREMENT
CREATE TABLE note (
    id int,
    title varchar(50),
    description varchar(50),
    PRIMARY KEY(id, title)
);
After running the query above, we can add 
AUTO_INCREMENT
feature to the existing column 
id
ALTER TABLE note MODIFY id int NOT NULL AUTO_INCREMENT;
If the column is not 
primary key
initially, we can modify the query, not to cause any error when adding 
AUTO_INCREMENT
to it
CREATE TABLE note (
    id int,
    title varchar(50),
    description varchar(50)
);
Adding 
AUTO_INCREMENT
feature to the column, that is not selected as a 
primary key
ALTER TABLE note MODIFY id int NOT NULL PRIMARY KEY AUTO_INCREMENT
by Valeri Tandilashvili
5 years ago
0
MySQL
AUTO_INCREMENT
1
Results: 1578