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MySQL - ignore insert error: duplicate entry
(5 answers)
Closed 4 years ago.
I have a question about insert data in a table.
My table is just composed of a primary key (that is composed by two foreign key).
The problem is: I don't know how to execute my script to insert all rows except non-existing values. Because in the script, some of the inserts are not available anymore.
For some reason, someone gave me the insert script but with some foreign key that were delete. So when I executed the script, I get an error "Constraint fail..." and it's normal.
But how to insert rows easily to avoid error due to invalid foreign key?
INSERT INTO `X_Y` (`x_id`, `y_id`) VALUES
(4, 1),
(4, 2),
(4, 3),
(4, 4),
(4, 5),
(5, 6),
(5, 7),
(5, 8),
(6, 9),
(6, 10),
(7, 11),
(8, 12),
(8, 13),
(11, 18),
(12, 19),
... ( about 2000 insert)
(1680, 2071);
For example : insert (4,1) can't be executed because foreign key x_id 4 does not exist anymore.
Try first inserting your data into a temporary table, with no constraints:
INSERT INTO temp (x_id, y_id)
VALUES
(4, 1),
(4, 2),
...;
Then, use the following query to insert into your target table:
INSERT INTO X_Y (x_id, y_id)
SELECT x_id, y_id
FROM temp t
WHERE
EXISTS (SELECT 1 FROM X x WHERE x.id = t.x_id) AND
EXISTS (SELECT 1 FROM Y y WHERE y.id = t.y_id);
The above insert checks, for every row, that the specified x_id and y_id values in fact have matching primary keys in the two parent tables.
Related
I have a MySQL Statement to insert data to 4 rows at a time. The insert is working but I'm having difficulty with the ON DUPLICATE KEY UPDATE.
I'm getting an error: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ''count = VALUES(11, 22, 33, 44)'' at line 15
Here is an example:
INSERT INTO table1 (id, dept, date, count)
VALUES
(1, 4, 2018-01-15, 3),
(2, 3, 2018-01-15, 4),
(3, 3, 2018-01-15, 14),
(4, 2, 2018-01-15, 11)
ON DUPLICATE KEY UPDATE
count = VALUES(11, 22, 33, 44)
I tried to wraps the dept and count update with '' but that didn't help. Is there a better way to update the count on DUPLICATES. Could you please help! Thanks!
The argument to VALUES() is supposed to be the name of a column being inserted into. It will use the value that would have been inserted into that column if there hadn't been a duplication.
INSERT INTO table1 (id, dept, date, count)
VALUES
(1, 4, 2018-01-15, 3),
(2, 3, 2018-01-15, 4),
(3, 3, 2018-01-15, 14),
(4, 2, 2018-01-15, 11)
ON DUPLICATE KEY UPDATE
count = VALUES(count)
If id = 1 already exists, this will set its count to 3 and leave all the other columns unchanged.
I'm using a stored procedure for this, and obviously below isn't going to be my exact code, but an highly trimmed version to get the idea across. Please keep in mind that I actually have a lot of filtering done on this temporary table, so adding anything to the CREATE TABLE query would just be more of a hassle than anything.
BEGIN
CREATE TEMPORARY TABLE IF NOT EXISTS filtered_results AS (SELECT * FROM users);
# Numerous filters removing stuff from the table.
END
For the purpose of this question, lets say that the tables structure is really simple, like so:
user_id INT(11) AUTO_INCREMENT PRIMARY
name VARCHAR(30) NOT NULL
Now let's say that I have a question table with the following structure:
question_id INT(11) AUTO_INCREMENT PRIMARY
user_id INT(11)
text VARCHAR(40)
Now lets say I want to iterate over the table and check some other tables to filter the users that don't have at least 4 questions. So something like this:
for each row in filtered_results
if count(question_id) < 4 where user_id = row.user_id in questions
delete row
end if
end loop
After some discussion and your last comment, I think I came up with a solution more elegant than running a cursor (as I previous mentioned in the comments).
You need to run a delete command into the results based on a LEFT JOIN of your to_be_deleted_table with your questions table. I'm taking into account that your to_be_deleted_table has the user_id on it.
Consider this sample:
create table filtered_results (
user_id integer,
name varchar(10)
);
insert into filtered_results values
(1, 'Bob'), (2, 'Sally'), (3, 'Cheer'), (4, 'Sid'), (5, 'Simon'),
(6, 'Lua'), (7, 'Liv'), (8, 'Taylor'), (9, 'Jay'), (10, 'Mike');
create table questions (
question_id integer,
user_id integer
);
insert into questions values
(1, 1), (2, 1), (3, 1), (4, 1), (5, 1),
(6, 2), (7, 2),
(8, 3), (9, 3), (10, 3), (11, 3),
(12, 4), (13, 4), (14, 4), (15, 4),
(16, 5), (17, 5), (18, 5), (19, 5),
(20, 6), (21, 6), (22, 6), (23, 6),
(24, 7), (24, 7), (24, 7), (24, 7);
This sample has all what you said, users that have 4 (or more questions), users that have less than 4 questions and users that don't have questions at all.
The query to delete the users where they don't have at least 4 question will be:
delete
from filtered_results
where user_id in
(select user_id
from (select f.user_id
from filtered_results f
LEFT JOIN questions q ON (f.user_id = q.user_id)
group by f.user_id
having count(*) < 4) a
);
You must be wondering why I have two subselects, that is because you need to trick the compiler so you can delete the rows from the same table you are doing the select, in this example filtered_results.
If you want to delete from another table based on the user_id at the filtered table just do as follow:
delete
from users
where user_id in
(select f.user_id
from filtered_results f
LEFT JOIN questions q ON (f.user_id = q.user_id)
group by f.user_id
having count(*) < 4
);
Remember that if that is the case you don't need to create the filtered_results just use the query that you create it as a subquery in the first case I showed.
Hope it helps.
And if you want to see it working, take a look at this SQLFiddle
I have a list of ids as (1,2,3...)
i called it $category_ids. Now in the same table there is a field of super_parent_category which means the highest label of that category in list.
Now i want to retrieve super parent ids for each of the category ids.
SELECT es_super_parent,es_id
FROM ephpb2b_categories
WHERE es_id IN ({$category_ids})");
The above query is returning me only 4 records as all of the ids in $category_ids belongs to these 4 categories.
But i want a result of all 50 records that are in $category_ids.
So if i am supplying 1,2,4,5,6,6,76,
I should return 1,3,4,5,6,66,2,
Thanks
It works for me. Double check your PHP variable $category_ids with a var_dump(), i.e.
I testet it with your provided sample data.
SELECT es_super_parent, es_id
FROM ephpb2b_categories
WHERE es_id IN (1, 2, 4, 5, 6, 6, 76);
and the following table schema:
CREATE TABLE ephpb2b_categories (
es_id INT PRIMARY KEY,
es_super_parent INT NOT NULL,
FOREIGN KEY (es_super_parent) REFERENCES ephpb2b_categories (es_id)
) ENGINE=InnoDB;
And inserted some data:
INSERT INTO ephpb2b_categories (es_id, es_super_parent) VALUES
(0, 0),
(1, 1),
(76, 76),
(2, 76),
(3, 2),
(4, 4),
(5, 5),
(6, 6),
(66, 6);
Here's a working SQL Fiddle
I know how to insert multiple rows with constant values in a single query:
INSERT INTO table
VALUES
(1, 'a', 'x'),
(2, 'b', 'y'),
(3, 'c', 'z');
But how do I do this conditionally? I want to make sure only non-existing* rows get inserted. Is it even possible to do it in a single query?
*A row exists when all its columns are identical to the one we are inserting
Use INSERT IGNORE INTO instead of INSERT INTO. The former will only insert rows, if no unique key constraints are violated.
INSERT IGNORE INTO table
VALUES
(1, 'a', 'x'),
(2, 'b', 'y'),
(3, 'c', 'z');
I have an insert sql statement, e.g.
INSERT INTO `table_a` (`col_a`, `col_b`, `col_c`, `col_d`) VALUES
(1, 2, 3, 4),
(2, 1, 6, 9),
(3, 1, 4, 5)
I want to insert this into another table, however the table I want to insert it into has a different structure to that of the sql statement (it has fewer fields) e.g.
table_b has columns 'col_a', 'col_b', 'col_d'
What do I have to do to the original sql statment so that I can get it to insert it into table_b. I guess it would be something along the lines of just ignoring the value which is in col_c and just sending this to a temp variable rather than a field.e.g.
INSERT INTO `table_b` (`col_a`, `col_b`, #temp_var, `col_d`) VALUES
(1, 2, 3, 4),
(2, 1, 6, 9),
(3, 1, 4, 5)
Use a temporary table:
CREATE TEMPORARY TABLE myTemp (
col_a integer,
col_b integer,
col_c integer,
col_d integer
);
INSERT INTO myTemp (col_a, col_b, col_c, col_d) VALUES (1, 2, 3, 4), (2, 1, 6, 9), (3, 1, 4, 5);
INSERT INTO table_a (SELECT col_a,col_b,col_d FROM myTemp);
The table gets dropped once your session ends (or you can remove it manually)
How about you remove it?
INSERT INTO table_b (col_a, col_b, col_d) VALUES (1, 2, 4), (2, 1, 9), (3, 1, 5)
This is ugly, and I have just tried in in SQLite, but I can image that it also works in MySQL (the documentation doesn't say it's not allowed) (update: see John's comment, it does not work in MySQL):
sqlite> create table t(a,b,c);
sqlite> insert into t (a,b,b,c) values (1,2,3,4);
sqlite> select * from t;
1|2|4