MySQL Insert Where query

Question

What's wrong with this query:

INSERT INTO Users( weight, desiredWeight ) VALUES ( 160, 145 ) WHERE id = 1;

It works without the WHERE clause. I've seemed to have forgot my SQL..

Answer 1

You simply cannot use WHERE when doing an INSERT statement:

 INSERT INTO Users( weight, desiredWeight ) VALUES ( 160, 145 ) WHERE id = 1;

should be:

 INSERT INTO Users( weight, desiredWeight ) VALUES ( 160, 145 );

The WHERE part only works in SELECT statements:

SELECT from Users WHERE id = 1;

or in UPDATE statements:

UPDATE Users set (weight = 160, desiredWeight = 145) WHERE id = 1;

Answer 2

Does WHERE-clause can be actually used with INSERT-INTO-VALUES in any case?

The answer is definitively no.

Adding a WHERE clause after INSERT INTO ... VALUES ... is just invalid SQL, and will not parse.

The error returned by MySQL is:

mysql> INSERT INTO Users( weight, desiredWeight ) VALUES ( 160, 145 ) WHERE id = 1;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE id = 1' at line 1

The most important part of the error message is

... syntax to use near 'WHERE id = 1' ...

which shows the specific part the parser did not expect to find here: the WHERE clause.

Answer 3

You can do conditional INSERT based on user input. This query will do insert only if input vars '$userWeight' and '$userDesiredWeight' are not blank

INSERT INTO Users(weight, desiredWeight )
select '$userWeight', '$userDesiredWeight'  
FROM (select 1 a ) dummy
WHERE '$userWeight' != '' AND '$userDesiredWeight'!='';

Answer 4

I do not believe the insert has a WHERE clause.

Answer 5

MySQL INSERT Syntax does not support the WHERE clause so your query as it stands will fail. Assuming your id column is unique or primary key:

If you're trying to insert a new row with ID 1 you should be using:

INSERT INTO Users(id, weight, desiredWeight) VALUES(1, 160, 145);

If you're trying to change the weight/desiredWeight values for an existing row with ID 1 you should be using:

UPDATE Users SET weight = 160, desiredWeight = 145 WHERE id = 1;

If you want you can also use INSERT .. ON DUPLICATE KEY syntax like so:

INSERT INTO Users (id, weight, desiredWeight) VALUES(1, 160, 145) ON DUPLICATE KEY UPDATE weight=160, desiredWeight=145

OR even like so:

INSERT INTO Users SET id=1, weight=160, desiredWeight=145 ON DUPLICATE KEY UPDATE weight=160, desiredWeight=145

It's also important to note that if your id column is an autoincrement column then you might as well omit it from your INSERT all together and let mysql increment it as normal.

Answer 6

Insert query doesn't support where keyword*

Conditions apply because you can use where condition for sub-select statements. You can perform complicated inserts using sub-selects.

For example:

INSERT INTO suppliers
(supplier_id, supplier_name)
SELECT account_no, name
FROM customers
WHERE city = 'Newark';

By placing a "select" in the insert statement, you can perform multiples inserts quickly.

With this type of insert, you may wish to check for the number of rows being inserted. You can determine the number of rows that will be inserted by running the following SQL statement before performing the insert.

SELECT count(*)
FROM customers
WHERE city = 'Newark';

You can make sure that you do not insert duplicate information by using the EXISTS condition.

For example, if you had a table named clients with a primary key of client_id, you could use the following statement:

INSERT INTO clients
(client_id, client_name, client_type)
SELECT supplier_id, supplier_name, 'advertising'
FROM suppliers
WHERE not exists (select * from clients
where clients.client_id = suppliers.supplier_id);

This statement inserts multiple records with a subselect.

If you wanted to insert a single record, you could use the following statement:

INSERT INTO clients
(client_id, client_name, client_type)
SELECT 10345, 'IBM', 'advertising'
FROM dual
WHERE not exists (select * from clients
where clients.client_id = 10345);

The use of the dual table allows you to enter your values in a select statement, even though the values are not currently stored in a table.

See also How to insert with where clause