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?
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...
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:
INSERT (and handle the error if the name already exists)INSERT IGNORE (which will INSERT ... ON DUPLICATE KEY UPDATE (which will execute the UPDATE at the end if name already exists, see documentation)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'); 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).
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---- 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; To overcome similar problem, I have made the table I am inserting 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' 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.
You can easily use following way :
INSERT INTO ..... ON DUPLICATE KEY UPDATE ... By this way you can insert any new raw and if you have duplicate data , replace specific column ( best column is 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 = '$current_time'; Brian Hooper : You almost hit the point but you have an error in your synatx. Your insert will never work. I tested on my database and here is the right answer:
INSERT INTO podatki (datum,ura,meritev1,meritev1_sunki,impulzi1,meritev2,meritev2_sunki,impulzi2) SELECT '$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
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 ) You are inserting not Updating the result. You can define the name column in primary column or set it is unique.
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,
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);
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