MySQL: Insert record if not exists in table [duplicate] - mysql

Question

This question already has answers here:
How can I do 'insert if not exists' in MySQL?
(11 answers)
Closed 2 years ago.
I am trying to execute the following query:
INSERT INTO table_listnames (name, address, tele)
VALUES ('Rupert', 'Somewhere', '022')
WHERE NOT EXISTS (
SELECT name FROM table_listnames WHERE name='value'
);
But this returns an error. Basically I don't want to insert a record if the 'name' field of the record already exists in another record - how to check if the new name is unique?

Answer 1

I'm not actually suggesting that you do this, as the UNIQUE index as suggested by Piskvor and others is a far better way to do it, but you can actually do what you were attempting:
CREATE TABLE `table_listnames` (
`id` int(11) NOT NULL auto_increment,
`name` varchar(255) NOT NULL,
`address` varchar(255) NOT NULL,
`tele` varchar(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB;
Insert a record:
INSERT INTO table_listnames (name, address, tele)
SELECT * FROM (SELECT 'Rupert', 'Somewhere', '022') AS tmp
WHERE NOT EXISTS (
SELECT name FROM table_listnames WHERE name = 'Rupert'
) LIMIT 1;
Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
SELECT * FROM `table_listnames`;
+----+--------+-----------+------+
| id | name | address | tele |
+----+--------+-----------+------+
| 1 | Rupert | Somewhere | 022 |
+----+--------+-----------+------+
Try to insert the same record again:
INSERT INTO table_listnames (name, address, tele)
SELECT * FROM (SELECT 'Rupert', 'Somewhere', '022') AS tmp
WHERE NOT EXISTS (
SELECT name FROM table_listnames WHERE name = 'Rupert'
) LIMIT 1;
Query OK, 0 rows affected (0.00 sec)
Records: 0 Duplicates: 0 Warnings: 0
+----+--------+-----------+------+
| id | name | address | tele |
+----+--------+-----------+------+
| 1 | Rupert | Somewhere | 022 |
+----+--------+-----------+------+
Insert a different record:
INSERT INTO table_listnames (name, address, tele)
SELECT * FROM (SELECT 'John', 'Doe', '022') AS tmp
WHERE NOT EXISTS (
SELECT name FROM table_listnames WHERE name = 'John'
) LIMIT 1;
Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
SELECT * FROM `table_listnames`;
+----+--------+-----------+------+
| id | name | address | tele |
+----+--------+-----------+------+
| 1 | Rupert | Somewhere | 022 |
| 2 | John | Doe | 022 |
+----+--------+-----------+------+
And so on...
Update:
To prevent #1060 - Duplicate column name error in case two values may equal, you must name the columns of the inner SELECT:
INSERT INTO table_listnames (name, address, tele)
SELECT * FROM (SELECT 'Unknown' AS name, 'Unknown' AS address, '022' AS tele) AS tmp
WHERE NOT EXISTS (
SELECT name FROM table_listnames WHERE name = 'Rupert'
) LIMIT 1;
Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
SELECT * FROM `table_listnames`;
+----+---------+-----------+------+
| id | name | address | tele |
+----+---------+-----------+------+
| 1 | Rupert | Somewhere | 022 |
| 2 | John | Doe | 022 |
| 3 | Unknown | Unknown | 022 |
+----+---------+-----------+------+

Answer 2

INSERT doesn't allow WHERE in the syntax.
What you can do: create a UNIQUE INDEX on the field which should be unique (name), then use either:
normal INSERT (and handle the error if the name already exists)
INSERT IGNORE (which will fail silently cause a warning (instead of error) if name already exists)
INSERT ... ON DUPLICATE KEY UPDATE (which will execute the UPDATE at the end if name already exists, see documentation)

Answer 3

Worked :
INSERT INTO users (full_name, login, password)
SELECT 'Mahbub Tito','tito',SHA1('12345') FROM DUAL
WHERE NOT EXISTS
(SELECT login FROM users WHERE login='tito');

Answer 4

MySQL provides a very cute solution :
REPLACE INTO `table` VALUES (5, 'John', 'Doe', SHA1('password'));
Very easy to use since you have declared a unique primary key (here with value 5).

Answer 5

INSERT IGNORE INTO `mytable`
SET `field0` = '2',
`field1` = 12345,
`field2` = 12678;
Here the mysql query, that insert records if not exist and will ignore existing similar records.
----Untested----

Answer 6

You can easily use the following way :
INSERT INTO ... ON DUPLICATE KEY UPDATE ...
In this way, you can insert any new raw and if you have duplicate data, replace a specific column ( The best columns are timestamps ).
For example :
CREATE TABLE IF NOT EXISTS Devices (
id INT(6) NOT NULL AUTO_INCREMENT,
unique_id VARCHAR(100) NOT NULL PRIMARY KEY,
created_at VARCHAR(100) NOT NULL,
UNIQUE KEY unique_id (unique_id),
UNIQUE KEY id (id)
)
CHARACTER SET utf8
COLLATE utf8_unicode_ci;
INSERT INTO Devices(unique_id, time)
VALUES('$device_id', '$current_time')
ON DUPLICATE KEY UPDATE time = '$current_time';

Answer 7

To overcome a similar problem, I have modified the table to have a unique column. Using your example, on creation I would have something like:
name VARCHAR(20),
UNIQUE (name)
and then use the following query when inserting into it:
INSERT IGNORE INTO train
set table_listnames='Rupert'

Answer 8

If you really can't get a unique index on the table, you could try...
INSERT INTO table_listnames (name, address, tele)
SELECT 'Rupert', 'Somewhere', '022'
FROM some_other_table
WHERE NOT EXISTS (SELECT name
FROM table_listnames
WHERE name='Rupert')
LIMIT 1;

Answer 9

This query works well:
INSERT INTO `user` ( `username` , `password` )
SELECT * FROM (SELECT 'ersks', md5( 'Nepal' )) AS tmp
WHERE NOT EXISTS (SELECT `username` FROM `user` WHERE `username` = 'ersks'
AND `password` = md5( 'Nepal' )) LIMIT 1
And you can create the table using following query:
CREATE TABLE IF NOT EXISTS `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(30) NOT NULL,
`password` varchar(32) NOT NULL,
`status` tinyint(1) DEFAULT '0',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
Note: Create table using second query before trying to use first query.

Answer 10

Brian Hooper :
You almost hit the point but you have an error in your synatx. Your insert will never work. I tested on my database and here is the right answer:
INSERT INTO podatki (datum,ura,meritev1,meritev1_sunki,impulzi1,meritev2,meritev2_sunki,impulzi2)
SELECT '$datum', '$ura', '$meritve1','$sunki1','$impulzi1','$meritve2','$sunki2','$impulzi2'
FROM dual
WHERE NOT EXISTS (SELECT datum,ura
FROM podatki
WHERE datum='$datum' and ura='$ura'
I'm giving you my example of y table. Insert is almost the same like Bian Hooper wrote, except that I put the select FROM DUAL ont from other table.
Cind regards, Ivan

Answer 11

This is not an answer, it's just a note. The query like the one in the accepted answer does not work if the inserted values are duplicates, like here:
INSERT INTO `addr` (`email`, `name`)
SELECT * FROM (SELECT 'user#domain.tld', 'user#domain.tld') AS tmp
WHERE NOT EXISTS (
SELECT `email` FROM `addr` WHERE `email` LIKE 'user#domain.tld'
);
Error
SQL query: Copy Documentation
MySQL said: Documentation
#1060 - Duplicate column name 'user#domain.tld'
In the contrary, the query like the one from Mahbub Tito's answer works fine:
INSERT INTO `addr` (`email`, `name`)
SELECT 'user#domain.tld', 'user#domain.tld'
WHERE NOT EXISTS (
SELECT `email` FROM `addr` WHERE `email` LIKE 'user#domain.tld'
);
1 row inserted.
Tested in MariaDB

Answer 12

insert into customer_keyskill(customerID, keySkillID)
select 2,1 from dual
where not exists (
select customerID from customer_keyskill
where customerID = 2
and keySkillID = 1 )

Answer 13

You are inserting not Updating the result.
You can define the name column in primary column or set it is unique.

Answer 14

I had a problem, and the method Mike advised worked partly, I had an error Dublicate Column name = '0', and changed the syntax of your query as this`
$tQ = "INSERT INTO names (name_id, surname_id, sum, sum2, sum3,sum4,sum5)
SELECT '$name', '$surname', '$sum', '$sum2', '$sum3','$sum4','$sum5'
FROM DUAL
WHERE NOT EXISTS (
SELECT sum FROM names WHERE name_id = '$name'
AND surname_id = '$surname') LIMIT 1;";
The problem was with column names. sum3 was equal to sum4 and mysql throwed dublicate column names, and I wrote the code in this syntax and it worked perfectly,

Answer 15

I had a similar problem and I needed to insert multiple if not existing. So from the examples above I came to this combination... it's here just in case somebody would need it.
Notice:
I had to define name everywhere as MSSQL required it... MySQL works with * too.
INSERT INTO names (name)
SELECT name
FROM
(
SELECT name
FROM
(
SELECT 'Test 4' as name
) AS tmp_single
WHERE NOT EXISTS
(
SELECT name FROM names WHERE name = 'Test 4'
)
UNION ALL
SELECT name
FROM
(
SELECT 'Test 5' as name
) AS tmp_single
WHERE NOT EXISTS
(
SELECT name FROM names WHERE name = 'Test 5'
)
) tmp_all;
MySQL:
CREATE TABLE names (
OID int(11) NOT NULL AUTO_INCREMENT,
name varchar(32) COLLATE utf8_unicode_ci NOT NULL,
PRIMARY KEY (OID),
UNIQUE KEY name_UNIQUE (name)
) ENGINE=InnoDB AUTO_INCREMENT=1;
or
MSSQL:
CREATE TABLE [names] (
[OID] INT IDENTITY (1, 1) NOT NULL,
[name] NVARCHAR (32) NOT NULL,
PRIMARY KEY CLUSTERED ([OID] ASC)
);
CREATE UNIQUE NONCLUSTERED INDEX [Index_Names_Name] ON [names]([name] ASC);

Answer 16

This query can be used in PHP code.
I have an ID column in this table, so I need check for duplication for all columns except this ID column:
#need to change values
SET #goodsType = 1, #sybType=5, #deviceId = asdf12345SDFasdf2345;
INSERT INTO `devices` (`goodsTypeId`, `goodsId`, `deviceId`) #need to change tablename and columnsnames
SELECT * FROM (SELECT #goodsType, #sybType, #deviceId) AS tmp
WHERE NOT EXISTS (
SELECT 'goodsTypeId' FROM `devices` #need to change tablename and columns names
WHERE `goodsTypeId` = #goodsType
AND `goodsId` = #sybType
AND `deviceId` = #deviceId
) LIMIT 1;
and now new item will be added only in case of there is not exist row with values configured in SET string