I've been doing some research and haven't found anything that I've been able to make work, unfortunately, and I think that stems from not understanding the MySQL construct in the examples I've been looking at.
What I'm trying to do is run an insert query, and do a check on values in 3 specific columns to ensure they don't exist, then insert, else do nothing.
My Table is pretty basic: id(int11), user(varchar(45)), label(varchar(255)), agent(varchar(255)), empid(varchar(10)).
My id is my Primary, with Auto increment, and here is my code I currently have that works on inserting, but doesn't have the handling in place for duplicates:
$i = 0;
foreach ($agents as $ag){
$sql = mysql_query("INSERT INTO `pms_users`
(`id`,`user`,`label`,`agent`,`empid`)
VALUES
(NULL, '$user','$group','$labels[$i]','$ag')");
$i ++;
}
The three columns I need to check against are the $user, $group, and $ag.
Add a unique index for (user, label, empid). Then the database won't allow you to create duplicates.
ALTER TABLE pms_users
ADD UNIQUE INDEX (user, label, empid);
If you can only have one row per combination of user, label and agent, you should define them as a unique constraint:
ALTER TABLE pms_users ADD CONSTRAINT pms_users_unq UNIQUE (`user`, `label`, `agent`);
And then let the database do the heavy lifting with an insert-ignore statement:
INSERT IGNORE INTO `pms_users`
(`user`, `label`, `agent`, `empid`)
VALUES ('some_user', 'some_label', 'some_agent', 123)
You can try insert on duplicate key update query.. It checks duplicate keys. If they exist MySQL do update query if not exist MySQL doing insert query.
Sure in your database you should declare unique keys.
Here is MySQL documentation for this case
https://dev.mysql.com/doc/refman/8.0/en/insert-on-duplicate.html
Related
I have a query like
Insert into tbl(str)values('a'),('b'),('c')
if i had a single insert then by using mysqli_insert_id($con) i could get last id inserted but how get all ids inserted in this multiple insert query?
This behavior of last_insert_id() is documented in the MySQL docs:
The currently executing statement does not affect the value of
LAST_INSERT_ID(). Suppose that you generate an AUTO_INCREMENT value
with one statement, and then refer to LAST_INSERT_ID() in a
multiple-row INSERT statement that inserts rows into a table with its
own AUTO_INCREMENT column. The value of LAST_INSERT_ID() will remain
stable in the second statement; its value for the second and later
rows is not affected by the earlier row insertions. (However, if you
mix references to LAST_INSERT_ID() and LAST_INSERT_ID(expr), the
effect is undefined.)
IF you really need it you can test it using foreach with array_push
<?php
$InsetQueryArray = array(
"Insert into tbl(str) values('a')",
"Insert into tbl(str) values ('b')",
"Insert into tbl(str) values('c')"
);
$allLasIncrementIds = array();
foreach ($InsetQueryArray as $value) {
//execute it mysql
//Then use array_push
array_push($allLastIncrementIds, mysqli_insert_id($con));
}
?>
If it is just for a few rows, you could switch to sending individual inserts with last_insert_id(). Otherwise it will slow down your application notably. You could make a marker for those bulk inserts, which gets set to a number identifying this bulk insert at the bulk insert itself and you can fetch those ids later on:
insert into tbl (stuff, tmp_marker) values ("hi",1715),("ho",1715),("hu",1715);
select group_concat(id) from tbl where tmp_marker = 1715;
update tbl set tmp_marker=0 where tmp_marker=1715;
If those bulk inserts have a meaning, you could also make a table import_tbl with user and time and filename or whatever and keep the 1715 as reference to that import.
EDIT: After discussion, I would go to an import-table
CREATE TABLE import (id int(11) not null auto_increment primary key, user_id int(11), tmstmp timestamp);
When an import starts, insert that:
INSERT INTO import set user_id = $userId;
in php:
$importId = last_insert_id();
$stmt = "insert into tbl (str, import_id) values ('a',$import_id), ('b', $import_id),('c',$importId);
Then you can do whatever you want with the id of your recently imported rows.
I have not made research if a multi-row-insert is guaranteed to lead to a consecutive row of IDs, as in a combination of last_insert_id() and num_rows is presupposed. And if that stays so, even when MySQL increases parallelization. So I would see it as dangerous to depend on it.
i have a contactnumber column in mysql database. In contactnumber column there are more than 20,000 entries. Now when i upload new numbers through .csv file, i dont want duplicate numbers in database.
How can i avoid duplicate numbers while inserting in database.
I initially implemented logic that checks each number in .csv file with each of the number in database.
this works but takes lot of time to upload .csv file containing 1000 numbers.
Pleae suggest how to minimize time required to upload .csv file while not uploading duplicate values.
Simply add a UNIQUE constraint to the contactnumber column:
ALTER TABLE `mytable` ADD UNIQUE (`contactnumber`);
From there you can use the IGNORE option to ignore the error you'd usually be shown when inserting a duplicate:
INSERT IGNORE INTO `mytable` VALUES ('0123456789');
Alternatively, you could use the ON DUPLICATE KEY UPDATE to do something with the dupe, as detailed in this question: MySQL - ignore insert error: duplicate entry
If your contactnumber should not be repeated then make it PRIMARY or at least a UNIQUE key. That way when a value is being inserted as a duplicate, insert will fail automatically and you won't have to check beforehand.
The way I would do it is to create a temporary table.
create table my_dateasyyyymmddhhiiss as select * from mytable where 1=0;
Do your inserts into that table.
and then query out the orphans on the between mytable and the temp table based on contactnumber
then run an inner join query between the two tables and fetch out the duplicate for your telecaller tracking.
finally drop the temporary table.
Thing that this does not address are duplicates within the supplied file (don't know if that would be an issue in this problem)
Hope this help
If you don't want to insert duplicate values in table and rather wants to keep that value in different table.
You can create trigger on table.
like this:
DELIMITER $$
CREATE TRIGGER unique_key BEFORE INSERT ON table1
FOR EACH ROW BEGIN
DECLARE c INT;
SELECT COUNT(*) INTO c FROM table1 WHERE itemid = NEW.itemid;
IF (c > 0) THEN
insert into table2 (column_name) values (NEW.itemid);
END IF;
END$$
DELIMITER ;
I would recommend this way
Alter the contactnumber column as UNIQUE KEY
Using phpmyadmin import the .csv file and check the option 'Do not abort on INSERT error' under Format-Specific Options before submitting
How can I check in MYSQL PHP if two columns are unique then not insert again, else if just one column is unique then insert, is that even possible to do in php?
EDIT:
Lets say I have a table like this,
userId | codeId
And I I send a query like this,
$query = $pdo->prepare('insert into table (userId, codeId) values (?,?)');
So now I want to check if userId and codeId are added already once do not insert again, and if just one is added, then do insert the entire query,
I hope its more understanding.
Set up a unique key for those columns, then the mysql query will FAIL when you try to insert.
Use REPLACE INTO instead of INSERT INTO ... ?
Do something like the code below (where TEXT_ID and TEXT_CATEGORY, are keys of table):
INSERT INTO
table_texts
SET
text_id = 174,
text_category = "pam_texto"
ON DUPLICATE KEY UPDATE
text_id = 174,
text_category = "pam_texto";
The above code tries to insert, but if the keys are duplicated performs an update on the line.
I believe the question have emerged as my irritation of doing twice as much work as I could imagine is necessary.
I accept the idea that I could be lacking experience with both MySQL and PHP to think of a simpler solution.
My issue is that I have several tables (and I'd might be adding more) and of these is a parent table, only containing two fields - an id (int) and a name identifying it.
At this moment, I have seven tables with at least 15 fields in each one. Every table has a field, containing the id which I can link to the parent table.
All of these data isn't required to be filled - you will just have to create that one entry in the parent table. For the other tables, I have separate forms.
Now, these forms are made for updating the data in the fields, which means I have to pull out the data from the table if any data is available.
What I would like to do is when I receive the data from my form, I could just use an UPDATE query in my model. But if the table I want to update doesn't have an entry for that specific id, I need to do an insert.
So, my current pseudo code is like this:
$sql = "SELECT id FROM table_x WHERE parent_id = ".$parent_id;
$res = $mysql_query($sql);
if( mysql_num_rows($res) == 1 )
{
$sql = "UPDATE table_x SET ... WHERE parent_id = ".$parent_id;
}
else
{
$sql = "INSERT INTO table_x VALUES ( ... )";
}
mysql_query($sql);
I have two do this for every table I have - can I do something different or smarter or is this just the way it has to be done? Cause this seems very inefficient to me.
Use
INSERT ... ON DUPLICATE KEY UPDATE Syntax
It will insert if record not found,
otherwise, it will update existing record,
and you can skip the check before insert - details
This assuming relation for each 7 table to the parent table is 1:1
Or use REPLACE instead of INSERT - it's an insert, but will do an DELETE and then INSERT when a unique key (such as the primary key) is violated.
in mysql you can do this:
INSERT INTO table
(
col1,
col2
) VALUES(
'val1',
'val2'
) ON DUPLICATE KEY UPDATE table SET
col2 = 'val2'
take a look at the documentation for more information
mysql_query("UPDATE table table_x ..... WHERE parent_id=".$parent_id);
if (mysql_affected_rows()==0) {
mysql_query("INSERT INTO .....");
}
I am working in PHP.
Please what's the proper way of inserting new records into the DB, which has unique field.
I am inserting lot of records in a batch and I just want the new ones to be inserted and I don't want any error for the duplicate entry.
Is there only way to first make a SELECT and to see if the entry is already there before the INSERT - and to INSERT only when SELECT returns no records? I hope not.
I would like to somehow tell MySQL to ignore these inserts without any error.
Thank you
You can use INSERT... IGNORE syntax if you want to take no action when there's a duplicate record.
You can use REPLACE INTO syntax if you want to overwrite an old record with a new one with the same key.
Or, you can use INSERT... ON DUPLICATE KEY UPDATE syntax if you want to perform an update to the record instead when you encounter a duplicate.
Edit: Thought I'd add some examples.
Examples
Say you have a table named tbl with two columns, id and value. There is one entry, id=1 and value=1. If you run the following statements:
REPLACE INTO tbl VALUES(1,50);
You still have one record, with id=1 value=50. Note that the whole record was DELETED first however, and then re-inserted. Then:
INSERT IGNORE INTO tbl VALUES (1,10);
The operation executes successfully, but nothing is inserted. You still have id=1 and value=50. Finally:
INSERT INTO tbl VALUES (1,200) ON DUPLICATE KEY UPDATE value=200;
You now have a single record with id=1 and value=200.
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.
from http://www.techonthenet.com/sql/insert.php
You can use triggers.
Also check this introduction guide to triggers.
Try creating a duplicate table, preferably a temporary table, without the unique constraint and do your bulk load into that table. Then select only the unique (DISTINCT) items from the temporary table and insert into the target table.
$duplicate_query=mysql_query("SELECT * FROM student") or die(mysql_error());
$duplicate=mysql_num_rows($duplicate_query);
if($duplicate==0)
{
while($value=mysql_fetch_array($duplicate_query)
{
if(($value['name']==$name)&& ($value['email']==$email)&& ($value['mobile']==$mobile)&& ($value['resume']==$resume))
{
echo $query="INSERT INTO student(name,email,mobile,resume)VALUES('$name','$email','$mobile','$resume')";
$res=mysql_query($query);
if($query)
{
echo "Success";
}
else
{
echo "Error";
}
else
{
echo "Duplicate Entry";
}
}
}
}
else
{
echo "Records Already Exixts";
}