I'm trying to update values already stored in a table, and I've implemented an auto-incrementing primary key column so that I can reference specific rows by number (as recommended here).
Using...
ALTER TABLE taxipassengers ADD COLUMN rid INT NOT NULL AUTO_INCREMENT PRIMARY KEY
The problem I'm running into though is that now I'm getting Column count doesn't match value count at row 1 when I insert the same data as before. It's like it wants me to give it a value for the PK. If I delete the column with the PK, the error goes away, and I'm back to square one.
Am I missing something?
EDIT: Here's the insert statement
INSERT INTO taxipassengers SELECT a.post_date, b.vendor_name, c.lastName, d.firstName, null as taxiGroup
FROM (select ID,post_date from wp_posts where post_type = 'shop_order') a,
(SELECT order_id,vendor_name FROM wp_wcpv_commissions) b,
(SELECT post_id,meta_value as lastName FROM wp_postmeta where meta_key ='_billing_last_name') c,
(SELECT post_id,meta_value as firstName FROM wp_postmeta WHERE meta_key ='_billing_first_name') d
WHERE a.ID = b.order_id and b.order_id=c.post_id and c.post_id = d.post_id;
Mind you, the insert statement worked before implementing the PK column, and it still works if I remove the PK column.
Possibly you are using this syntax to insert rows
INSERT INTO mytable VALUES (1, 'abc', 'def');
INSERT syntax from MySQL manual
The columns for which the statement provides values can be specified as follows:
If you do not specify a list of column names for INSERT ... VALUES or INSERT ... SELECT, values for every column in the table must be provided by the VALUES list or the SELECT statement. If you do not know the order of the columns in the table, use DESCRIBE tbl_name to find out.
You must add new column to your INSERT query. For autoincrement column NULL can be inserted to generate new value. And your column will be added last by default (if you don't use AFTER in ALTER TABLE).
To add a column at a specific position within a table row, use FIRST or AFTER col_name. The default is to add the column last. You can also use FIRST and AFTER in CHANGE or MODIFY operations to reorder columns within a table.
So, now your INSERT must look like this:
INSERT INTO mytable VALUES (1, 'abc', 'def', NULL); -- use NULL for autoincrement
INSERT INTO mytable (col1, col2, col3) VALUES (1, 'abc', 'def'); -- or add column names
First check if your database allows mutable PK, or prefers stable PK .
Please read through below articles, I am sure you will get what's going wrong.
http://rogersaccessblog.blogspot.in/2008/12/what-is-primary-key.html
First, the value in the primary key cannot be duplicated
Can we update primary key values of a table?
Related
UPDATE AggregatedData SET datenum="734152.979166667",
Timestamp="2010-01-14 23:30:00.000" WHERE datenum="734152.979166667";
It works if the datenum exists, but I want to insert this data as a new row if the datenum does not exist.
UPDATE
the datenum is unique but that's not the primary key
Jai is correct that you should use INSERT ... ON DUPLICATE KEY UPDATE.
Note that you do not need to include datenum in the update clause since it's the unique key, so it should not change. You do need to include all of the other columns from your table. You can use the VALUES() function to make sure the proper values are used when updating the other columns.
Here is your update re-written using the proper INSERT ... ON DUPLICATE KEY UPDATE syntax for MySQL:
INSERT INTO AggregatedData (datenum,Timestamp)
VALUES ("734152.979166667","2010-01-14 23:30:00.000")
ON DUPLICATE KEY UPDATE
Timestamp=VALUES(Timestamp)
Try using this:
If you specify ON DUPLICATE KEY UPDATE, and a row is inserted that would cause a duplicate value in a UNIQUE index orPRIMARY KEY, MySQL performs an [UPDATE`](http://dev.mysql.com/doc/refman/5.7/en/update.html) of the old row...
The ON DUPLICATE KEY UPDATE clause can contain multiple column assignments, separated by commas.
With ON DUPLICATE KEY UPDATE, the affected-rows value per row is 1 if the row is inserted as a new row, 2 if an existing row is updated, and 0 if an existing row is set to its current values. If you specify the CLIENT_FOUND_ROWS flag to mysql_real_connect() when connecting to mysqld, the affected-rows value is 1 (not 0) if an existing row is set to its current values...
This is not too bad, but we could actually combine everything into one query. I found different solutions on the internet. The simplest, but MySQL only solution is this:
INSERT INTO wp_postmeta (post_id, meta_key)
SELECT
?id,
‘page_title’
FROM
DUAL
WHERE
NOT EXISTS (
SELECT
meta_id
FROM
wp_postmeta
WHERE
post_id = ?id
AND meta_key = ‘page_title’
);
UPDATE
wp_postmeta
SET
meta_value = ?page_title
WHERE
post_id = ?id
AND meta_key = ‘page_title’;
Link to documentation.
I had a situation where I needed to update or insert on a table according to two fields (both foreign keys) on which I couldn't set a UNIQUE constraint (so INSERT ... ON DUPLICATE KEY UPDATE won't work). Here's what I ended up using:
replace into last_recogs (id, hasher_id, hash_id, last_recog)
select l.* from
(select id, hasher_id, hash_id, [new_value] from last_recogs
where hasher_id in (select id from hashers where name=[hasher_name])
and hash_id in (select id from hashes where name=[hash_name])
union
select 0, m.id, h.id, [new_value]
from hashers m cross join hashes h
where m.name=[hasher_name]
and h.name=[hash_name]) l
limit 1;
This example is cribbed from one of my databases, with the input parameters (two names and a number) replaced with [hasher_name], [hash_name], and [new_value]. The nested SELECT...LIMIT 1 pulls the first of either the existing record or a new record (last_recogs.id is an autoincrement primary key) and uses that as the value input into the REPLACE INTO.
I need two columns in table that would have same value on insert. Is there any way to do it from database side?
So you want to let one column use the auto_increment feature, but make another column in the same table also have the same value?
I can't think of a reason you would need this feature. Perhaps you could explain what you're trying to accomplish, and I can suggest a different solution?
A trigger won't work for this. It's a chicken-and-egg problem:
You can't change any column's value in an AFTER trigger.
But the auto-increment value isn't set yet when a BEFORE trigger executes.
It also won't work to use a MySQL 5.7 GENERATED column:
CREATE TABLE MyTable (
id INT AUTO_INCREMENT PRIMARY KEY,
why_would_you_want_this INT GENERATED ALWAYS AS (id)
);
ERROR 3109 (HY000): Generated column 'why_would_you_want_this'
cannot refer to auto-increment column.
You can't do it in a single SQL statement. You have to INSERT the row, and then immediately do an UPDATE to set your second column to the same value.
CREATE TABLE MyTable (
id INT AUTO_INCREMENT PRIMARY KEY,
why_would_you_want_this INT
);
INSERT INTO MyTable () VALUES ();
UPDATE MyTable SET why_would_you_want_this = LAST_INSERT_ID()
WHERE id = LAST_INSERT_ID();
You could alternatively generate the ID value using some other mechanism besides AUTO_INCREMENT (for example a Memcached incrementing key). Then you could insert the new value in both columns:
INSERT INTO MyTable (id, why_would_you_want_this) VALUES ($gen_id, $gen_id);
Define a before or after insert trigger and assign the value of the 2nd field in the trigger.
If the 1st field is an auto increment column, then you need to use an after insert trigger. If your application assigns value to the 1st field, then you can use a before insert trigger.
However, I would no necessarily duplicate the value on insert. You can leave the 2nd field as null on insert, which would mean that its value is the same as the 1st field's. The only drawback of this approach is that it may be more difficult to create joins on the 2nd field.
You can do this in one query by using the primary key (assumed to be id) and setting your column (assumed to be columnName):
"INSERT INTO tableName SET `columnName` = (SELECT MAX(x.id) FROM tableName x)+1"
This will not work if you have deleted the most recent primary key row however. To get past this, you can insert into the id as well:
"INSERT INTO tableName SET `columnName` = (SELECT MAX(x.id) FROM tableName x)+1, `id`= (SELECT MAX(x.id) FROM tableName x)+1"
However, this solution has the downside (or upside depending on the case) of reusing primary key values that have already been deleted.
suggested way:
To use the actual auto_increment value, you can do this:
"INSERT INTO tableName SET `columnName` = (SELECT `AUTO_INCREMENT` FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'db_name' AND TABLE_NAME = 'table_name')"
Sources that helped me solve this: Prashant Pimpale's answer
Let's say I have two columns member_id, email in one table users. I'm trying to add a new row if no similar data is found with below statement:
INSERT INTO users(member_id, email)
VALUES (1,'k#live.com')
WHERE NOT EXISTS (SELECT * FROM users WHERE member_id=1 AND email='k#live.com');
However, it's not working. #1064 - 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 EXISTS
Please shed some light. Thanks.
Assuming you have a unique constraint on member_id, email or a combination of both, I believe you will be better served with an INSERT IGNORE, if the record doesn't exist, it will be inserted.
INSERT IGNORE INTO users(member_id, email)
values (1, 'k#live.com');
If there is no unique constraint, use this technique here
INSERT INTO users(member_id, email)
SELECT 1,'k#live.com'
FROM dual
WHERE NOT EXISTS
(SELECT * FROM users WHERE member_id=1 AND email='k#live.com');
Dual is used in the dummy select rather than users in order to limit the rows inserted to 1.
There cannot be a WHERE clause in an INSERT ... VALUES ... statement.
The normal pattern for avoiding duplicates is to add UNIQUE constraint(s).
If you want to avoid adding any duplicate "member_id" values, and you also want to avoid adding any duplicate "email" values, then
CREATE UNIQUE INDEX mytab_UX1 ON mytab (member_id);
CREATE UNIQUE INDEX mytab_UX2 ON mytab (email);
Whenever an INSERT or UPDATE attempts to create a duplicate value, a duplicate key exception (error) will be thrown. MySQL provides the IGNORE keyword which will suppress the error, and allow the statement to complete successfully, but without introducing any duplicates.
Given an empty table, the first statement would insert a row, the second and third statements would not.
INSERT IGNORE INTO mytab (member_id, email) VALUES (1,'k#live.com');
INSERT IGNORE INTO mytab (member_id, email) VALUES (2,'k#live.com');
INSERT IGNORE INTO mytab (member_id, email) VALUES (1,'aaa#bbb.com');
If you want to restrict just the combination of the two columns to being unique, that is you would allow the 2nd and 3rd statements to insert a row, then you'd add a UNIQUE constraint on the combination of the two columns, rather than two separate unique indexes as above.
CREATE UNIQUE INDEX mytab_UX1 on mytab (member_id, email);
Aside from that convention, say you don't have a unique constraint, but you only want to modify the behavior of the single insert statement, then you can use a SELECT statement to return the values you want to insert, and then you can add a WHERE clause to the SELECT.
To avoid adding any duplicate member_id or duplicate email, then something like this would accomplish that:
INSERT INTO mytab (member_id, email)
SELECT s.member_id, s.email
FROM (SELECT 1 AS member_id, 'k#live.com' AS email) s
WHERE NOT EXISTS (SELECT 1 FROM mytab d WHERE d.member_id = s.member_id)
AND NOT EXISTS (SELECT 1 FROM mytab e WHERE e.email = s.email)
For best performance with a large table, you're going to want at least two indexes, one with a leading column of member_id, and one with a leading column of email. The NOT EXISTS subqueries can make use of an index to quickly locate a "matching" row, rather than scanning every row in the table.)
Again, if it's just the combination of the two columns you want to be unique, you'd use a single NOT EXISTS subquery, as in your original query.
Alternatively, you could use an anti-join pattern as an equivalent to the NOT EXISTS subquery.
INSERT INTO mytab (member_id, email)
SELECT s.member_id, s.email
FROM (SELECT 2 AS member_id, 'k#live.com' AS email) s
LEFT
JOIN mytab d
ON d.member_id = s.member_id
LEFT
JOIN mytab e
ON e.email = s.email
WHERE d.member_id IS NULL
AND e.email IS NULL
Structure table:
id (int primary key)
name (varchar 100)
date(datetime)
For insert I use query:
INSERT INTO table (name, date) VALUES ('t1','$date');
For delete row I use query:
DELETE FROM table WHERE name = 't1';
I would like want how make 1 query: first insert, if row with it name already exist, than delete row, and insert again.
Tell me please how to make it?
Create a UNIQUE index over your name column:
ALTER TABLE `table` ADD UNIQUE (name);
If you genuinely want to "delete row and insert again", then you can use REPLACE instead of INSERT. As documented:
REPLACE works exactly like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or a UNIQUE index, the old row is deleted before the new row is inserted.
Therefore, in your case:
REPLACE INTO `table` (name, date) VALUES ('t1','$date');
However, if instead of deleting the existing record and then inserting a new one you merely want to update the existing record, you can use INSERT ... ON DUPLICATE KEY UPDATE:
INSERT INTO `table` (name, date) VALUES ('t1','$date')
ON DUPLICATE KEY UPDATE date = VALUES(date);
The most material difference is in the treatment of columns for which you do not provide explicit values (such as id in your example): REPLACE will result in the new record having the default value, whereas INSERT ... ON DUPLICATE KEY UPDATE will result in the old value being retained.
What you want to do is use MySQL's on duplicate update feature.
Can be used like this :
INSERT INTO table (name, date) VALUES ('t1','$date')
ON DUPLICATE KEY UPDATE name=VALUES(name),dateVALUES(date);
Of course for that to happen a dupliate violation must occur.
insert into table (name, date) values('t1','$date') on duplicate key update name=values(name), date=values(date)
Are you looking for an update query?
Update will set a value on an already existing row.
UPDATE table SET date = '$newdate' WHERE name = 't1';
The best way to do this is using the mysql methods together with your query.
If you make the 'name' field unique:
id (int primary key)
name (varchar 100) NOT NULL UNIQUE
date(datetime)
And alter the query to:
INSERT INTO table
(name, date) VALUES ('t1','$date')
ON DUPLICATE KEY UPDATE date = "$date"
UPDATE AggregatedData SET datenum="734152.979166667",
Timestamp="2010-01-14 23:30:00.000" WHERE datenum="734152.979166667";
It works if the datenum exists, but I want to insert this data as a new row if the datenum does not exist.
UPDATE
the datenum is unique but that's not the primary key
Jai is correct that you should use INSERT ... ON DUPLICATE KEY UPDATE.
Note that you do not need to include datenum in the update clause since it's the unique key, so it should not change. You do need to include all of the other columns from your table. You can use the VALUES() function to make sure the proper values are used when updating the other columns.
Here is your update re-written using the proper INSERT ... ON DUPLICATE KEY UPDATE syntax for MySQL:
INSERT INTO AggregatedData (datenum,Timestamp)
VALUES ("734152.979166667","2010-01-14 23:30:00.000")
ON DUPLICATE KEY UPDATE
Timestamp=VALUES(Timestamp)
Try using this:
If you specify ON DUPLICATE KEY UPDATE, and a row is inserted that would cause a duplicate value in a UNIQUE index orPRIMARY KEY, MySQL performs an [UPDATE`](http://dev.mysql.com/doc/refman/5.7/en/update.html) of the old row...
The ON DUPLICATE KEY UPDATE clause can contain multiple column assignments, separated by commas.
With ON DUPLICATE KEY UPDATE, the affected-rows value per row is 1 if the row is inserted as a new row, 2 if an existing row is updated, and 0 if an existing row is set to its current values. If you specify the CLIENT_FOUND_ROWS flag to mysql_real_connect() when connecting to mysqld, the affected-rows value is 1 (not 0) if an existing row is set to its current values...
This is not too bad, but we could actually combine everything into one query. I found different solutions on the internet. The simplest, but MySQL only solution is this:
INSERT INTO wp_postmeta (post_id, meta_key)
SELECT
?id,
‘page_title’
FROM
DUAL
WHERE
NOT EXISTS (
SELECT
meta_id
FROM
wp_postmeta
WHERE
post_id = ?id
AND meta_key = ‘page_title’
);
UPDATE
wp_postmeta
SET
meta_value = ?page_title
WHERE
post_id = ?id
AND meta_key = ‘page_title’;
Link to documentation.
I had a situation where I needed to update or insert on a table according to two fields (both foreign keys) on which I couldn't set a UNIQUE constraint (so INSERT ... ON DUPLICATE KEY UPDATE won't work). Here's what I ended up using:
replace into last_recogs (id, hasher_id, hash_id, last_recog)
select l.* from
(select id, hasher_id, hash_id, [new_value] from last_recogs
where hasher_id in (select id from hashers where name=[hasher_name])
and hash_id in (select id from hashes where name=[hash_name])
union
select 0, m.id, h.id, [new_value]
from hashers m cross join hashes h
where m.name=[hasher_name]
and h.name=[hash_name]) l
limit 1;
This example is cribbed from one of my databases, with the input parameters (two names and a number) replaced with [hasher_name], [hash_name], and [new_value]. The nested SELECT...LIMIT 1 pulls the first of either the existing record or a new record (last_recogs.id is an autoincrement primary key) and uses that as the value input into the REPLACE INTO.