how can I get the row id of tbl_questions and send it to tbl_link_qa
and then tbl_answers get to send it's row number to tbl_link_qa (same with tbl_questions) but this time it must correspond to the first row number from tbl_questions that was inserted first at tbl_link_qa
i need to link the row number of a question from tbl_questions and the row number of an answer from tbl_answers.
need help really bad
rec_id---qRec_id---aRec_id
96------------0-----------0
95------------0-----------0
I need to make it like this >>
rec_id---qRec_id----aRec_id
96----------123----------456
95----------124----------
123 and 124 is the row number from tbl_questions inserted into tbl_link_qa and 456 is from tbl_answers
Use mysql_insert_id to get the auto_increment ID of the last row you inserted.
Ex:
mysql_query("INSERT INTO tbl_questions VALUES (something)");
$question_id = mysql_insert_id();
mysql_query("INSERT INTO tbl_answer VALUES (something)");
$answer_id = mysql_insert_id();
mysql_query("INSERT INTO tbl_link_qa (qRec_id, aRec_id) VALUES ($question_id, $answer_id)");
Related
I used INSERT INTO SELECT to copy values (multiple rows) from one table to another. Now, my problem is how do I insert rows with its corresponding IDs from different tables (since it's normalized) into a gerund table because it only outputs one row in my gerund table. What should I do to insert multiple rows and their corresponding IDs in the gerund table.
My code for the gerund table goes like this.
$insert = "INSERT INTO table1 SELECT * FROM sourcetable"; // where id1 is pk of table1.
$result =mysqli_query($conn,$insert)
$id1=mysqli_insert_id($conn);
Now table 1 has inserted multiple rows same as the other 2 tables.
Assuming id.. are the foreign keys
INSERT INTO gerundtable (pk, id1,id2,id3) VALUES ($id1,$id2,$id3);
My problem is it doesn't yield multiple rows.
According to MySql documentation:
For a multiple-row insert, LAST_INSERT_ID() and mysql_insert_id() actually return the AUTO_INCREMENT key from the first of the inserted rows. This enables multiple-row inserts to be reproduced correctly on other servers in a replication setup.
So, grab the number of records being copied, and the LAST_INSERT_ID() and you should be able to map exact IDs with each copied row.
In the lines of:
$mysqli->query("Insert Into dest_table Select * from source_table");
$n = $mysqli->affected_rows; // number of copied rows
$id1 = $mysqli->insert_id; // new ID of the first copied row
$id2 = $mysqli->insert_id + 1; // new ID of the second copied row
$id3 = $mysqli->insert_id + 2; // new ID of the third copied row
...
$mysqli->query("INSERT INTO gerundtable (pk, id1,id2,id3) VALUES ($id1,$id2,$id3)");
Thank you for trying to understand and also answering my question. I resolved my own code. I used while loop to get the ids of every row and didn't use INSERT INTO SELECT.
Here is the run down. SInce I'm just using my phone bare with my way posting.
$sqlselect = SELECT * FROM table1;
While($row=mysqli_fetch_array(table1){
$insertquery...
$id1=mysqli_insert_id($conn)
$insertgerundtable = INSERT INTO gerundtable VALUES ( $id1, $id2);
}
Following is my database in mysql:
Id Username Password
1 admin admin
2 jay jay1
3 suman xyza
4 chintan abcde
This is my code in php:
$fetchid = mysql_query(" SELECT MAX(Id) As max From user;");
$row = mysql_fetch_array($fetchid);
$largest = $row['max'];
$largest++;
$user= $_POST['username'];
$pass= $_POST['password'];
$result = mysql_query(" INSERT INTO `proshell`.`user` (
`Id` ,
`Username` ,
`Password`
)"."
VALUES (
'".$largest."', '".$user."', '".$pass."'
);");
Problem:
Now if I delete row with Id=1 and then re-enter the data then it should use ID=1 then Again I reinsert the data it use ID=5
It works like this:
if I delete row with Id=1 and then re-enter the data the Id it gets is 5 but then 1 is free so,
What should I write to perform that task.
First, if you set your Id column to AUTO_INCREMENT you don't need the following part in your code at all:
$fetchid = mysql_query(" SELECT MAX(Id) As max From user;");
$row = mysql_fetch_array($fetchid);
$largest = $row['max'];
$largest++;
Because AUTO_INCREMENT will automatic add new value to your ID colume.
But if you don't set it to AUTO_INCREMENT, the above code will grab the MAXIMUM ID value (in this case, 4).
When you re-enter your data again after you delete the row 1, the MAXIMUM ID still 4, so your new ID value will be 5 (from $largest++;).
.....
If you really need to use consecutive ids as you PK, you need to re-write you code but I suggest you to use UUID for you ID column instead.
You can easily generate UUID by using uuid().
How about the UUID performance? Refer to Dancrumb's answer about this:
A UUID is a Universally Unique ID. It's the universally part that you should be considering here.
Do you really need the IDs to be universally unique? If so, then UUIDs
may be your only choice.
I would strongly suggest that if you do use UUIDs, you store them as a
number and not as a string. If you have 50M+ records, then the saving
in storage space will improve your performance (although I couldn't
say by how much).
If your IDs do not need to be universally unique, then I don't think
that you can do much better then just using auto_increment, which
guarantees that IDs will be unique within a table (since the value
will increment each time)
see. UUID performance in MySQL?
EDIT: I don't suggest you run query on the whole table just to find the MAX ID value before inserting new value everytime, because it will give you a performance penalty (Imagine that if you have million rows and must query on them everytime just to insert a new row, how much workload causes to your server).
It is better to do the INSERT just as INSERT, no more than that.
EDIT2:
If you really want to use consecutive ids, then how about this solution?
Create new TABLE just for store the ids for insert (new ids and the ids that you deleted).
For example:
CREATE TABLE cons_ids (
ids INT PRIMARY KEY,
is_marker TINYINT DEFAULT 0
);
then initial ids with values from 1-100 and set marker to be '1' on some position, e.g. 80th of whole table. This 'marker' uses to fill your ids when it's nearly to empty.
When you need to INSERT new Id to your first table, use:
$result = mysql_query("SELECT ids, marker FROM cons_ids ORDER BY ids ASC LIMIT 1;");
$row = mysql_fetch_row($result);
and use $row[0] for the following code:
INSERT INTO yourtable (Id, Username, Password)
VALUES ($row[0], $username, $password);
DELETE FROM cons_ids
WHERE ids = $row[0];
This code will automatically insert the lowest number in cons_ids as your Id and remove it from the cons_ids table. (so next time you do insert, it will be the next lowest number)
Then following with this code:
if ($row[1] == 1) {
//add new 100 ids start from the highest ids number in cons_ids table
//and set new marker to 80th position again
}
Now each time you delete a row from your first table, you just add the Id from the row that you deleted to cons_ids, and when you do INSERT again, it will use the Id number that you just deleted.
For example: your current ids in cons_ids is 46-150 and you delete row with Id = 14 from first table, this 14 will add to your cons_ids and the value will become 14, and 46-150. So next time you do INSERT to your first table, your Id will be 14!!.
Hope my little trick will help you solve your problem :)
P.S. This is just an example, you can modify it to improve its performance.
First of all, as I understand, you are selecting highest column ID which should be always the last one (since you set auto-increment on ID column).
But what are you trying to do is actually filling up holes after delete query, right?
If you are really looking for such approach, try to bypass delete operation by making new boolean column where you flag record if it is active or not (true/false).
SQL table change:
Id Username Password Active
1 admin admin false
2 jay jay1 true
3 suman xyza false
4 chintan abcde true
PHP request:
$fetchid = mysql_query(" SELECT MIN(Id) As min FROM user WHERE active = false;");
$result = mysql_query(" INSERT INTO `proshell`.`user` (
`Id` ,
`Username` ,
`Password`
`Active`
)"."
VALUES (
'".$largest."', '".$user."', '".$pass."', 'true'
);");
I have two tables first called messages and the other called messages_reply.
I used this code to insert into messages table:
$query = "INSERT INTO `messages` VALUES('', '$id', '$otherId', '')";
$query_run = mysqli_query($connect, $query);
I have the first column auto_increment thats why I left it empty by writing ''
Now i want this auto_increment value that i have inserted to be inserted in the other table called messages_reply
Do I have to create another query to return it or there is an instant way to insert it here and there?
you have to select the last id on table messages first, then you can insert that last id + 1 into messages reply
$query_sel_last_id = "SELECT id FROM messages ORDER BY id desc LIMIT 1"; // select the last id
after that, you only need to insert to messages_reply, remember to plus the value
$query_sel_last_id + 1
EDIT: gordon's solution is better and simpler, LAST_INSERT_ID()
I am inserting multiple rows using one query and, obviously, the ID column auto increments each row. I want to create another ID column and have the ID remain the same for all rows inserted during the query. So if I insert 10 rows during one query, I want all 10 rows to have the id "1". How can this be done? Thanks for any help
If I understood your question correctly, you want to supply an ID for the specific group of INSERT statements.
Assumming you have this schema
CREATE TABLE TableName
(
RecordID INT AUTO_INCREMENT PRIMARY KEY,
OtherColumn VARCHAR(25) NOT NULL,
GroupID INT NOT NULL
)
You can have two statements for this:
1.) Getting the last GroupID and increment it by 1.
SELECT COALESCE(MAX(GroupID), 0) + 1 AS newGroupID FROM TableName
2.) once you have executed it, store the value in a variable. Use this variable for all the insert statement,
$groupID = row['newGroupID'];
$insert1 = "INSERT INTO TableName(OtherColumn, GroupID) VALUES ('a', $groupID)";
$insert2 = "INSERT INTO TableName(OtherColumn, GroupID) VALUES ('b', $groupID)";
$insert3 = "INSERT INTO TableName(OtherColumn, GroupID) VALUES ('c', $groupID)";
UPDATE 1
SQLFiddle Demo
Im making a drag n drop sortable list. What I am trying to do is increment a column in MySql based on its id value automatically when new records are entered. ie:
if i have a row with an id = 3, and it is the first record enetered
for that id, then its recordid = 1.
if i have a row with an id = 14, and it is the first record enetered
for that id, then its recordid = 1.
if i have a row with an id = 3, and it is the second record enetered
for that id, then its recordid = 2.
So i want it to autoincrement recordid based on its id value. not the whole table value. Does that make sence? what code would i need in php to find the highest value recordid pertaining to the id and then increment it by 1 when a new record is entered? Thanks in advance.
Something like this?
INSERT INTO `table` (`id`, `recordid`) VALUES
(
$id,
(SELECT MAX(`recordid`) + 1 AS `rid` FROM `table` WHERE `id` = $id)
);
You could probably optimize it way further though.