How can I set a minimum length for my primary key ID which is auto incremented. Now the auto increment starts at 1 and goes up from there. However I would like the id to be at least 5 characters long. So it would start at 10001, 10002, 10003 etc
If you have the table, but not the column run the following code with the appropriate modifications:
ALTER TABLE MyTableName
ADD MyTableNameId INT NOT NULL AUTO_INCREMENT,
ADD INDEX (MyTableNameId);
If you have already created the column, you can do this:
ALTER TABLE MyTableName AUTO_INCREMENT = 10001;
Beginning with MySQL 5.0.3, InnoDB supports the AUTO_INCREMENT = N table option in CREATE TABLE and ALTER TABLE statements.
You can't define a length, but you can specify what value it starts with.
At declaration time:
CREATE TABLE test
(
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
whatever VARCHAR(10),
...
) AUTO_INCREMENT = 100000;
Or, after declaring / at run time:
ALTER TABLE test AUTO_INCREMENT=200000;
Related
im using mysql to make a table
CREATE TABLE school.student(
Std_id INT NOT NULL AUTO_INCREMENT,
Std_name CHAR(40) NOT NULL,
Std_Birth DATE,
Std_Group CHAR(2) check(Std_Group in ('G1', 'G2','G3','G4'))
);
and im trying to make the auto incrment start from 1000 and incrment by 2 (1000,1002,1004,1006.....) while using CREATE
You may try this solution.
CREATE TABLE school.student(
Std_id INT NOT NULL AUTO_INCREMENT,
Std_name CHAR(40) NOT NULL,
Std_Birth DATE,
Std_Group CHAR(2) check(Std_Group in ('G1', 'G2','G3','G4'))
) AUTO_INCREMENT = 1000;
set ##auto_increment_increment=2;
while, you set the value of ##auto_increment_increment it will
effect all over the database. Because, It's Global variable for
MySQL.
For setting starting value from 1000 you may need to set
AUTO_INCREMENT at the end of the Create Table syntax.
You can do it as follows :
INSERT INTO _students
(Std_id, Std_name, Std_Birth, Std_Group)
select case when count(Std_id) >= 1 then max(Std_id) + 2 else 1000 end as Std_id, 'test', '2022-10-10', 'G1'
from _students;
select case when count(Std_id) >= 1 then max(Std_id) + 2 else 1000 end : this will check if there are any records in your table, if not it will insert first with id 1000
Create table #autoincre
(
Std_id int not null Primary key identity (1000,2),
Std_name char(40) Not null,
Std_Birth date,
Std_Group char(2) check(Std_group in ('G1','G2','G3','G4'))
)
Drop table #autoincre
insert into #autoincre values('Ajay','2022-07-10','G1')
select * from #autoincre
You can start the auto_increment for a given table at 1000 with a table option:
CREATE TABLE school.student(
...
) AUTO_INCREMENT=1000;
Note that the next id generated will be one greater than the table option is set to, so it will generate value 1001. If you want it to include the value 1000, set the table option AUTO_INCREMENT=999.
Your other requirement is more difficult.
https://dev.mysql.com/doc/refman/8.0/en/replication-options-source.html#sysvar_auto_increment_increment says:
It is not possible to restrict the effects of these two variables to a single table; these variables control the behavior of all AUTO_INCREMENT columns in all tables on the MySQL server.
In other words, if you set auto_increment_increment=2, this will apply to all tables with an auto-increment column. It is not a per-table option.
You could set auto_increment_increment=2 as a session variable only before inserting into the student table, then set it back to the default before inserting to another table. That sounds like it will be error-prone, because you could forget to change the session variable.
How do I set the initial value for an "id" column in a MySQL table that start from 1001?
I want to do an insert "INSERT INTO users (name, email) VALUES ('{$name}', '{$email}')";
Without specifying the initial value for the id column.
Use this:
ALTER TABLE users AUTO_INCREMENT=1001;
or if you haven't already added an id column, also add it
ALTER TABLE users ADD id INT UNSIGNED NOT NULL AUTO_INCREMENT,
ADD INDEX (id);
MySQL - Setup an auto-incrementing primary key that starts at 1001:
Step 1, create your table:
create table penguins(
my_id int(16) auto_increment,
skipper varchar(4000),
PRIMARY KEY (my_id)
)
Step 2, set the start number for auto increment primary key:
ALTER TABLE penguins AUTO_INCREMENT=1001;
Step 3, insert some rows:
insert into penguins (skipper) values("We need more power!");
insert into penguins (skipper) values("Time to fire up");
insert into penguins (skipper) values("kowalski's nuclear reactor.");
Step 4, interpret the output:
select * from penguins
prints:
'1001', 'We need more power!'
'1002', 'Time to fire up'
'1003', 'kowalski\'s nuclear reactor'
MySQL Workbench
If you want to avoid writing sql, you can also do it in MySQL Workbench by right clicking on the table, choose "Alter Table ..." in the menu.
When the table structure view opens, go to tab "Options" (on the lower bottom of the view), and set "Auto Increment" field to the value of the next autoincrement number.
Don't forget to hit "Apply" when you are done with all changes.
PhpMyAdmin:
If you are using phpMyAdmin, you can click on the table in the lefthand navigation, go to the tab "Operations" and under Table Options change the AUTO_INCREMENT value and click OK.
With CREATE TABLE statement
CREATE TABLE my_table (
id INT UNSIGNED NOT NULL AUTO_INCREMENT,
name VARCHAR(100) NOT NULL,
PRIMARY KEY (id)
) AUTO_INCREMENT = 100;
or with ALTER TABLE statement
ALTER TABLE my_table AUTO_INCREMENT = 200;
First you need to add column for auto increment
alter table users add column id int(5) NOT NULL AUTO_INCREMENT FIRST
This query for add column at first.
Now you have to reset auto increment initial value. So use this query
alter table users AUTO_INCREMENT=1001
Now your table started with 1001
You could also set it in the create table statement.
`CREATE TABLE(...) AUTO_INCREMENT=1000`
Alternatively, If you are too lazy to write the SQL query. Then this solution is for you.
Open phpMyAdmin
Select desired Table
Click on Operations tab
Set your desired initial Value for AUTO_INCREMENT
Done..!
For this you have to set AUTO_INCREMENT value
ALTER TABLE tablename AUTO_INCREMENT = <INITIAL_VALUE>
Example
ALTER TABLE tablename AUTO_INCREMENT = 101
Also , in PHPMyAdmin , you can select table from left side(list of tables) then do this by going there.
Operations Tab->Table Options->AUTO_INCREMENT.
Now, Set your values and then press Go under the Table Options Box.
SET GLOBAL auto_increment_offset=1;
SET GLOBAL auto_increment_increment=5;
auto_increment_increment: interval between successive column values
auto_increment_offset: determines the starting point for the AUTO_INCREMENT column value.
The default value is 1.
read more here
i understand,below column will be signed int by default.
id INT(6);
Can an auto increment column specified below be signed by default? Mysql starts the value from 1 for an auto increment column.
id INT(6) AUTO_INCREMENT PRIMARY KEY
Yes, you can create an auto increment primary key with a signed int. Try this:
CREATE TABLE mytable( id int(6) AUTO_INCREMENT PRIMARY KEY);
Then the following queries are both valid
INSERT INTO mytable values();
INSERT INTO mytable values(-10);
This will result in the table having a row with -10 and another with 1 as values. But you will run into problems if you try this:
ALTER TABLE mytable AUTO_INCREMENT=-10;
yes, you cannot have auto increment values that are negative numbers.
After a lot of searches... I looked for a solution with a TRIGGER called BEFORE INSERT ! I found this : https://stackoverflow.com/a/43441586/2282880
Here is my variant :
CREATE TRIGGER `invertID`
BEFORE INSERT ON `<table>`
FOR EACH ROW SET NEW.id=CONCAT("-", (
SELECT `auto_increment`
FROM INFORMATION_SCHEMA.TABLES
WHERE table_name = '<table>')
)
It worked for me fine.
It was the best way I found to sync in both directions two databases with same schema without same ID's in my tables.
How do I set the initial value for an "id" column in a MySQL table that start from 1001?
I want to do an insert "INSERT INTO users (name, email) VALUES ('{$name}', '{$email}')";
Without specifying the initial value for the id column.
Use this:
ALTER TABLE users AUTO_INCREMENT=1001;
or if you haven't already added an id column, also add it
ALTER TABLE users ADD id INT UNSIGNED NOT NULL AUTO_INCREMENT,
ADD INDEX (id);
MySQL - Setup an auto-incrementing primary key that starts at 1001:
Step 1, create your table:
create table penguins(
my_id int(16) auto_increment,
skipper varchar(4000),
PRIMARY KEY (my_id)
)
Step 2, set the start number for auto increment primary key:
ALTER TABLE penguins AUTO_INCREMENT=1001;
Step 3, insert some rows:
insert into penguins (skipper) values("We need more power!");
insert into penguins (skipper) values("Time to fire up");
insert into penguins (skipper) values("kowalski's nuclear reactor.");
Step 4, interpret the output:
select * from penguins
prints:
'1001', 'We need more power!'
'1002', 'Time to fire up'
'1003', 'kowalski\'s nuclear reactor'
MySQL Workbench
If you want to avoid writing sql, you can also do it in MySQL Workbench by right clicking on the table, choose "Alter Table ..." in the menu.
When the table structure view opens, go to tab "Options" (on the lower bottom of the view), and set "Auto Increment" field to the value of the next autoincrement number.
Don't forget to hit "Apply" when you are done with all changes.
PhpMyAdmin:
If you are using phpMyAdmin, you can click on the table in the lefthand navigation, go to the tab "Operations" and under Table Options change the AUTO_INCREMENT value and click OK.
With CREATE TABLE statement
CREATE TABLE my_table (
id INT UNSIGNED NOT NULL AUTO_INCREMENT,
name VARCHAR(100) NOT NULL,
PRIMARY KEY (id)
) AUTO_INCREMENT = 100;
or with ALTER TABLE statement
ALTER TABLE my_table AUTO_INCREMENT = 200;
First you need to add column for auto increment
alter table users add column id int(5) NOT NULL AUTO_INCREMENT FIRST
This query for add column at first.
Now you have to reset auto increment initial value. So use this query
alter table users AUTO_INCREMENT=1001
Now your table started with 1001
You could also set it in the create table statement.
`CREATE TABLE(...) AUTO_INCREMENT=1000`
Alternatively, If you are too lazy to write the SQL query. Then this solution is for you.
Open phpMyAdmin
Select desired Table
Click on Operations tab
Set your desired initial Value for AUTO_INCREMENT
Done..!
For this you have to set AUTO_INCREMENT value
ALTER TABLE tablename AUTO_INCREMENT = <INITIAL_VALUE>
Example
ALTER TABLE tablename AUTO_INCREMENT = 101
Also , in PHPMyAdmin , you can select table from left side(list of tables) then do this by going there.
Operations Tab->Table Options->AUTO_INCREMENT.
Now, Set your values and then press Go under the Table Options Box.
SET GLOBAL auto_increment_offset=1;
SET GLOBAL auto_increment_increment=5;
auto_increment_increment: interval between successive column values
auto_increment_offset: determines the starting point for the AUTO_INCREMENT column value.
The default value is 1.
read more here
I am using MySQL 5. I need to set the seed value as 1000 for my auto increment field.
How can I set it?
To set when creating your table:
CREATE TABLE xxx(...) AUTO_INCREMENT = 1000;
To set after creating the table:
ALTER TABLE xxx AUTO_INCREMENT = 1000;
If the table already exists, you can do this:
ALTER TABLE mytable AUTO_INCREMENT = 1000;
But make sure the highest value in the auto_increment column is less than 1000.
If you are creating a new table, you can do this:
CREATE TABLE mytable (id INT UNSIGNED PRIMARY KEY AUTO_INCREMENT)
AUTO_INCREMENT = 1000;