I try to execute insert or ignore into WDCategory(name,userID) values('Cate 1',1) which name is a unique column but not successful if there is a record with same name in the table. "Not Successful" means that the query fail instead of execute and insert nothing. I have try insert into WDCategory(name,userID) values('Cate 1',1) If Not Exists but nothing change.
Update: I try
insert or replace into WDCategory(name,userID) values('Cate 1',1)
it works. But the record now have a new id (auto increase). Is there any way to keep the old values?
Please help!
Related
I created a table in MySql
CREATE TABLE newuser(id VARCHAR(10) PRIMARY KEY,sname VARCHAR(20));
When I INSERT record it works fine
INSERT INTO newuser VALUE('abc123','monika');
But sometimes I don't want to supply id in the INSERT query and sometimes I want to supply. In case I don't supply id MySql automatically generate one.
What can I do to get both below query works?
INSERT INTO newuser VALUE('abc123','monika');
INSERT INTO newuser VALUE('nikita');
'I don't understood ANYTHING' - very new then.
Firstly second insert statement is invalid please review https://dev.mysql.com/doc/refman/8.0/en/insert.html -
'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, SELECT statement, or TABLE statement.'
Secondly uuid is a function in which 'A UUID is designed as a number that is globally unique in space and time.' https://dev.mysql.com/doc/refman/8.0/en/insert.html
You can easily select uuid() to see what it produces.
You will need to increase the id size
If you wish to use it in an insert
insert into users values (uuid(),<sname>);
I tried to write MySQL Insert and update query in one query but seems it not working can someone please explain me what is the error of following code, thank you..
IF EXISTS
(
SELECT *
FROM contact
WHERE account_id='".$_GET['acc']."' AND contact_id='".$_GET['con']."'
)
UPDATE contact SET
category='".$_GET['cat']."', shares='".$_GET['sh']."'
WHERE account_id='".$_GET['acc']."' AND contact_id='".$_GET['con']."'
ELSE
INSERT INTO contact
(account_id,contact_id, category, shares)
VALUES ('".$_GET['acc']."', '".$_GET['con']."', '".$_GET['cat']."', '".$_GET['sh']."')
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.
See REPLACE syntax
I am currently using MySQL. I have a table that has an auto_increment 'id' field, and an 'imgname' field containing a string that is the file name of an image.
I need to generate the 'imgname' value using the auto_increment value that is create by an INSERT INTO statement. The problem is, I don't know this value until I can use mysql_insert_id, AFTER the insert query has run. I would like to know if it's possible to access this value DURING the insert query somehow and then use it to generate my string in the query statement.
Thanks in advance.
I would keep the id and imgname independent of each other and combine the two on SELECT when needed. If the need is frequent enough, create a view.
Have a look at LAST_INSERT_ID() function. If performance is not an issue, INSERT regularly, and then UPDATE using LAST_INSERT_ID(), like:
UPDATE table SET name = CONCAT(name, "-", LAST_INSERT_ID()) WHERE id = LAST_INSERT_ID();
I would like to insert a record into a table if a record doesnt exist already exist with that domain name. The following SQL should achieve this but is getting an error.
The reason I want to do the update first is because I am doing multiple updates later in my code and need the record in my table first before doing all of the updates.
Why am I getting an error on this mySQL query?
insert into domain (name)
values ('domain.com.au')
WHERE NOT EXISTS
(
select name
from domain
where name = 'domain.com.au'
);
Both queries when split work fine but when together do not.
Let your database handle it for you. Use a unique index on name and your INSERT will fail if you try to insert a duplicate.
CREATE UNIQUE INDEX idx_name ON domain (name)
You cannot combine WHERE with INSERT clause. Use REPLACE INTO instead.
What error are you getting?
My guess would be the that the select inside the 'where not exists' is not allowed.
If I insert multiple records with a loop that executes a single record insert, the last insert id returned is, as expected, the last one. But if I do a multiple records insert statement:
INSERT INTO people (name,age)
VALUES ('William',25), ('Bart',15), ('Mary',12);
Let's say the three above are the first records inserted in the table. After the insert statement I expected the last insert id to return 3, but it returned 1. The first insert id for the statement in question.
So can someone please confirm if this is the normal behavior of LAST_INSERT_ID() in the context of multiple records INSERT statements. So I can base my code on it.
Yes. This behavior of last_insert_id() is documented in the MySQL docs:
Important
If you insert multiple rows using a single INSERT statement, LAST_INSERT_ID() returns the value generated for the first inserted row only. The reason for this is to make it possible to reproduce easily the same INSERT statement against some other server.
This behavior is mentioned on the man page for MySQL. It's in the comments but is not challenged, so I'm guessing it's the expected behavior.
I think it's possible if your table has unique autoincrement column (ID) and you don't require them to be returned by mysql itself. I would cost you 3 more DB requests and some processing. It would require these steps:
Get "Before MAX(ID)" right before your insert:
SELECT MAX(id) AS before_max_id FROM table_name`
Make multiple INSERT ... VALUES () query with your data and keep them:
INSERT INTO table_name
(col1, col2)
VALUES
("value1-1" , "value1-2"),
("value2-1" , "value2-2"),
("value3-1" , "value3-2"),
ON DUPLICATE KEY UPDATE
Get "After MAX(ID)" right after your insert:
SELECT MAX(id) AS after_max_id FROM table_name`
Get records with IDs between "Before MAX(ID)" and "After MAX(ID)" including:
SELECT * FROM table_name WHERE id>$before_max_id AND id<=$after_max_id`
Do a check of retrieved data with data you inserted to match them and remove any records that were not inserted by you. The remaining records have your IDs:
foreach ($after_collection as $after_item) {
foreach ($input_collection as $input_item) {
if ( $after_item->compare_content($input_item) ) {
$intersection_array[] = $after_item;
}
}
}
This is just how a common person would solve it in a real world, with parts of code. Thanks to autoincrement it should get smallest possible amount of records to check against, so they will not take lot of processing. This is not the final "copy & paste" code - eg. you have to create your own function compare_content() according you your needs.