I'm trying to insert an ingredient to an ingredients table if it doesn't exist.
I'm using the following syntax:
INSERT INTO ingredient(Name)
(
SELECT 'ingName' FROM dummytable WHERE
(SELECT count(*) FROM ingredient WHERE Name = 'ingName')=0)
This does not seem to work (0 rows affected), even though the SELECT query seem to return the desired result (an entry which contains "ingName").
The "ingredient" table has 2 columns: Name, id (id is auto incremented)
Thanks,
Li
Its better to add unique index on the name column:
ALTER TABLE `ingredient` ADD UNIQUE(`Name`)
After doing that you can use INSERT IGNORE:
INSERT IGNORE INTO `ingredient` ... /* anything */
That's because your inner query SELECT count(*) FROM ingredient WHERE Name = 'ingName' is returning a value > 0 and hence the upper query SELECT 'ingName' FROM dummytable WHERE is not selecting any rows and so no insert is happening.
I tried the same with a test table having 2 column name|value and it did worked fine
INSERT INTO test1(name) (
SELECT 'name' FROM test2 WHERE
(
SELECT count(*) FROM test2 WHERE name = 'bilboa'
)
=0
)
Inserted 2 rows with value name cause that's what I am selecting in select query and my test table 2 rows.
Related
I've got the following table:
productId price
1 price_value1
2 price_value2
3 price_value3
I would like to insert a new product into the table and assign it a new productId. In this case its value equals to 4.
So I want my new table to look like so:
productId price
1 price_value1
2 price_value2
3 price_value3
4 price_value4
So as far as I understand, in order to do that I have to somehow retrieve the max value of productId and insert it using INSERT INTO mytable VALUES (productId + 1, price_value4).
But how do I find out the maximum value of productId?
I tried INSERT INTO mytable VALUES (SELECT MAX(productId) + 1 FROM mytable, price_value4) but it didn't work.
This should Work:
Select the max(productID) and price_value4 as a columns from mytable and insert the result.
INSERT INTO mytable (SELECT MAX(productId) + 1, 'price_value4' FROM mytable);
However, if you are not going to jump some number you can just add an auto increment id key to product_id and then you will have only to insert the price, the product ID will be incremented automatically..
This will do so :
ALTER TABLE mytable
MODIFY COLUMN `productId` INT(10) UNSIGNED PRIMARY KEY AUTO_INCREMENT;
you can change INT(10) with the INT(5) for example depanding on the size you want to give to your productId column
EDIT :
In return to the OP question in comments why his solution wouldn't work
Some suggetions says you have to make the SELECT statment in insert always between parenthesis
INSERT INTO mytable VALUES ( (SELECT MAX(ID)+1 FROM mytable) , price_value4)
.. In my Case it Return
(1093): You can't specify target table
'mytable' for update in FROM clause
AND HERE IS WHY (Quoting From the documentation)
When selecting from and inserting into the same table, MySQL creates
an internal temporary table to hold the rows from the SELECT and then
inserts those rows into the target table. However, you cannot use
INSERT INTO t ... SELECT ... FROM t when t is a TEMPORARY table,
because TEMPORARY tables cannot be referred to twice in the same
statement
BUT there is away to overcome by using a query instead of the table itself in the FROM, which has the effect of copying the requested table values instead of referencing the one that you are updating..
INSERT INTO mytable VALUES (
(SELECT MAX(ID)+1 FROM (SELECT * FROM mytable ) as mytmp ),
'price_value4');
OR (Quoting From the documentation)
To avoid ambiguous column reference problems when the SELECT and the
INSERT refer to the same table, provide a unique alias for each table
used in the SELECT part, and qualify column names in that part with
the appropriate alias.
INSERT INTO mytable Values ( (SELECT MAX(ID)+1 FROM mytable as mytmp) , 'price_value4')
This is a duplicate question. In order to take advantage of the auto-incrementing capability of the column, do not supply a value for that column when inserting rows.
A simple syntax to create table
CREATE TABLE Product (
productId MEDIUMINT NOT NULL AUTO_INCREMENT,
price INT NOT NULL,
PRIMARY KEY (productid)
);
While inserting supplied default or leave column as blank or supplied value as NULL. Take a look at below code snippet.
INSERT INTO Product (price) VALUES
('10'),('20'),('4'),
('30');
refer this link
I need to make a comparison between two (or more) tables with around 60.000 rows and about 60 columns.
In these tables there are two values on which I want to run a query. The purpose of the query is to count the rows which exists in TABLE_A but don't exist in TABLE_B based on two values in the row.
I've ran the following query:
SELECT id
FROM table_a ta
WHERE NOT EXISTS (
SELECT id
FROM table_b tb
WHERE ta.value1=tb.value1 AND ta.value2=tb.value2
)
As said, I've tried the code above and some variations on it. But to run this query it takes ages before it's finished. I hope to find a solution which runs in under 10 seconds.
Next query I tried, and of which I thought was working:
SELECT value1, value2
FROM (
SELECT ta.value1, ta.value2
FROM table_a ta
UNION ALL
SELECT tb.value1, tb.value2
FROM table_b tb
) result
GROUP BY value1, value2
HAVING COUNT(*) = 1
ORDER BY value1
The code shows me all differences between the two tables. So if valueX exists in TABLE_A but not in TABLE_B it's shown and vice versa.
So in short, I want to get all rows from TABLE_A which are not present in TABLE_B based on two values in the row.
Hope someone can help, thanks!
Why not use a join?
/* Create a table called NAMES */
CREATE TABLE NAMES(Id integer PRIMARY KEY, Name text, LastName text);
CREATE TABLE OTHERNAMES(Id integer PRIMARY KEY, Name text, LastName text);
/* Create few records in this table */
INSERT INTO NAMES VALUES(1,'Tom','Riddle');
INSERT INTO NAMES VALUES(2,'Lucy','I love');
INSERT INTO NAMES VALUES(3,'Frank','Frankly');
INSERT INTO NAMES VALUES(4,'Jane','Austen');
INSERT INTO NAMES VALUES(5,'Robert','Downey');
INSERT INTO OTHERNAMES VALUES(2,'Lucy','I love');
INSERT INTO OTHERNAMES VALUES(3,'Frank','Frankly');
INSERT INTO OTHERNAMES VALUES(4,'Jane','Austen');
INSERT INTO OTHERNAMES VALUES(5,'Robert','Downey');
select * from NAMES
LEFT JOIN OTHERNAMES on
NAMES.Name = OTHERNAMES.Name
AND Names.LastName = OTHERNAMES.LastName
where OTHERNAMES.id is null
See it online http://sqlfiddle.com/#!9/640c53/1
If you use a LEFT JOIN Items that don't exist in the right table will be replaced with null entries, which can be filtered with a where.
I don't know how efficient that is with your 60.000 database but this usually does the trick for me.
After some trial and error I have improved the second block of code. I noticed an additional field in my table which I could use to further filter the results.
SELECT date, value1, value2
FROM (
SELECT date, value1, value2
FROM (
SELECT ta.date, ta.value1, ta.value2
FROM table_1 ta
UNION ALL
SELECT tb.date, tb.value1, tb.value2
FROM table_2 tb
) filter
GROUP BY value1, value2
HAVING COUNT(*) = 1
) result
WHERE date='YYYY-MM-DD'
This code filters the results in under 4 seconds.
Anyway, thanks everyone for the trouble.
I have s MySQL database and I need to insert some specific data in a table. The data should be as follows:
SELECT id FROM a_table WHERE ... returns me a list of ids.
I need to insert n rows in second_table where n is the count of the returned rows from the first query. The second table requires 2 fields - The first one will be a record from the first query and the second one will be an integer, that I will pass from my script.
For example: If the first query returns (12,14,17,18) and the integer from my script is 5 I need to create a query, that will insert (12,5),(14,5),(17,5),(18,5) and I need this done in the database layer - I don't want to create a select statement, then create a query and then run it.
I need something like this (this is not a real query - It just shows what I need):
INSERT INTO second_table (user_id,group_id) VALUES ((12,14,17,18),5)
or to be more precise like this:
INSERT INTO second_table (user_id,group_id) VALUES ((SELECT id FROM a_table WHERE ...),5)
Is there a way to do this in SQL only (no tsql - sql only)
You can include a literal value in a SELECT:
INSERT INTO second_table (user_id, group_id)
SELECT id, 5
FROM a_table
WHERE ...
INSERT INTO
second_table
(
user_id
,group_id
)
SELECT
id
,5
FROM
first_table
WHERE
...
see the MySQL docs for more details on INSERT...SELECT syntax:
http://dev.mysql.com/doc/refman/5.1/en/insert-select.html
Hi you can try query given below
Insert into items select item_sold_qty , 5 from sales
INSERT INTO second_table
SELECT id , 5 FROM a_table WHERE ...
thanks
I wanna insert a row when the name not exists in the table.
When the table is empty,it cannot insert anything, anyone can help me?
Here is my code:
INSERT INTO `ediftpdb`.`users`(
name
,passwd
,vendor
)
SELECT
'L001'
,'12345678a'
,'MKTPLS'
FROM `ediftpdb`.`users`
WHERE NOT EXISTS (SELECT * FROM `ediftpdb`.`users` WHERE name='L001' AND vendor = 'MKTPLS' ) LIMIT 1;
P.S.
I found a funny stuff, when ediftpdb.users is empty, code like below returns nothing.
SELECT
'L001'
,'12345678a'
,'MKTPLS'
FROM `ediftpdb`.`users`
The better way to do this is to create a unique multi-part index on name and vendor columns:
CREATE UNIQUE INDEX name_vendor ON ediftpdb.users( name, vendor )
Then:
INSERT IGNORE INTO ediftpdb.users ( name, passwd, vendor )
VALUES ( 'L001', '12345678a', 'MKTPLS' )
will do exactly what you want to do.
As #Martin Smith pointed, when the table ediftpdb.users is empty the FROM ediftpdb.users
results in no rows. If it had 100 rows, then your statement would try to INSERT 100 (identical) records into the table.
Try this:
INSERT INTO
...
SELECT
'L001'
,'12345678a'
,'MKTPLS'
FROM (SELECT 1) AS dummy
WHERE NOT EXISTS ...
I need UNION two tables with creating new field, where 1 for first table, and 2 for second.
I tried
(
SELECT field, 1 AS tmp
FROM table1
)
UNION
(
SELECT field, 2 AS tmp
FROM table2
)
But in result, tmp field was full of "1".
How it can be implemented?
Your query should work fine. The only thing you should change is UNION should be UNION ALL to give better performance. Without the ALL it defaults to UNION DISTINCT which causes the rows to be compared for duplicates*, but the way you have constructed them guarantees that there cannot be duplicates so this extra check is a waste of time. Here is some test code I used to verify that what you are doing ought to work:
CREATE TABLE table1 (field NVARCHAR(100) NOT NULL);
INSERT INTO table1 (field) VALUES
('foo1'),
('bar1'),
('baz1');
CREATE TABLE table2 (field NVARCHAR(100) NOT NULL);
INSERT INTO table2 (field) VALUES
('foo2'),
('bar2'),
('baz2');
SELECT field, 1 AS tmp
FROM table1
UNION ALL
SELECT field, 2 AS tmp
FROM table2
Result:
'foo1', 1
'bar1', 1
'baz1', 1
'foo2', 2
'bar2', 2
'baz2', 2
If you only get rows where tmp was equal to 1, maybe your table2 was empty?
*See the documentation for UNION.
The default behavior for UNION is that duplicate rows are removed from the result. The optional DISTINCT keyword has no effect other than the default because it also specifies duplicate-row removal. With the optional ALL keyword, duplicate-row removal does not occur and the result includes all matching rows from all the SELECT statements.
You are very close
Create YourNewTable
SELECT field, 1 AS tmp
FROM table1
UNION ALL
SELECT field, 2 AS tmp
FROM table2