this is my query
CASE
WHEN (SELECT COUNT(*) FROM `table` WHERE `ip`= 'myip' )=1
THEN UPDATE `table`
SET `last_active`=".date("Ymd").",`last_time`=".date("His")."
WHERE `ip`= 'myip';
ELSE (INSERT INTO `table`(ip)
VALUES("myip"));
END
but its not woking .the problem should be from here
(SELECT COUNT(*) FROM `table` WHERE `ip`= 'myip' )=1
how can I fix this ? or how to do this another way?
the date("Ymd") function is just the php function to return the date the problem isnt from that
thanks
I think you are trying to do this:
create unique index unq_table_ip on table(ip);
insert into table (ip)
values ('myip')
on duplicate key update last_active = curdate(),
last_time = curtime();
The unique index (or equivalently a unique constraint) guarantees that a given ip only appears once in the table. Let the database do this work for you -- this is called maintaining relational integrity.
Notes:
This assumes that last_active and last_time have default values in the table.
You should use the database time, not the application time for this purpose (after all, different clients could have different time values).
You should probably put the date/time values into a single datetime column, say last_active_datetime.
Define unique constraint on ip column and then use ON DUPLICATE KEY UPDATE:
insert into `table` (ip) values ("myup")
on duplicate key update
`last_active`=".date("Ymd").",`last_time`=".date("His")."
Related
I have table with AUTO_INCREMENT field defined as PRIMARY_KEY.
I have columns like:
vote_id,vote_user_id,vote_ask_id,vote_comment_id,vote_post_id,vote_type,vote_status
I want to INSERT new records but before I do that I want to check if there is a row with columns(vote_user_id,vote_ask_id,vote_type) as same as the new data I want INSERT.
CONDITIONS:
IF ROW EXISTS
THEN UPDATE tableName SET vote_status=new_value, vote_time=new_time
ELSE
INSERT NEW RECORDS
I have searched the internet and learnt about MySQL ..ON DUPLICATE KEY UPDATE.
I have realize this statement will not be helpful to my task since it only checks for DUPLICATE KEY(...PRIMARY_KEY or UNIQUE FIELD).
I have learnt also on MySQL REPLACE INTO ...and likewise this will not be helpful to my problem since that is also bind to PRIMARY_KEY or UNIQUE index.
I learnt I could use MERGE....USING...statements
but this was giving me errors so i read more about it and I relised it only work in SQL server (Microsoft)
Please how best can someone help me solve this?
I tried this on MERGE staments:
MERGE {$votes_table} WITH (HOLDLOCK) AS VT
USING ({$Qid},{$vote_type},{$CUid},{$vote_status}) AS VTS (vote_ask_id,vote_type,vote_user_id,vote_status)
ON( VT.vote_ask_id = VTS.vote_ask_id AND VT.vote_user_id=VTS.vote_user_id AND VT.vote_type=VTS.vote_type)
WHEN MATCHED THEN
UPDATE SET VT.status=VST.vote_status , VT.vote_time='{$current_time}' WHERE VT.vote_user_id=VTS.vote_user_id AND VT.vote_ask_id=VTS.vote_ask_id AND VT.vote_type=VTS.vote_type
WHEN NOT MATCHED THEN INSERT (vote_ask_id,vote_type,vote_status,vote_user_id,vote_time) VALUES('{$Qid}','{$vote_type}','{$vote_up_status}','{$CUid}','{$current_time}')
In MySQL, use ON DUPLICATE KEY:
INSERT INTO tablename (vote_user_id, vote_ask_id, vote_type, . . . )
VALUES (new_vote_user_id, new_vote_ask_id, new_vote_type . . . )
ON DUPLICATE KEY UPDATE vote_status = VALUES(vote_status), vote_time = VALUES(vote_time);
For this to work, you need a unique index/constraint on the columns that define a unique row:
CREATE UNIQUE INDEX unq_tablename_3 ON tablename(vote_user_id, vote_ask_id, vote_type);
You do want insert ... on duplicate key update: in MySQL, this is the right way to do what you want.
To start with, you need to create a unique constraint on the tuple of concerned columns:
create unique index votes_table_unique_idx
on votes_table(vote_user_id, vote_ask_id, vote_type);
Then, you can do something like:
insert into votes_table(vote_user_id, vote_ask_id, vote_type, vote_comment_id, vote_post_id, vote_status)
values(...)
on duplicate key update
vote_comment_id = values(vote_comment_id),
vote_post_id = values(vote_post_id)
vote_status = values(vote_status)
Structure table:
id (int primary key)
name (varchar 100)
date(datetime)
For insert I use query:
INSERT INTO table (name, date) VALUES ('t1','$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 = "$date"
Alright, i have revised the question to also include what i have so far, and what i want to do. So here goes it:
CREATE ORDER (
product_nat_id int(3) NOT NULL,
name VARCHAR(20),
PRIMARY KEY (product_nate_id)
)
INSERT INTO ORDER(product_nat_id, name) VALUES(1, 'Product 1');
INSERT INTO ORDER(product_nat_id, name) VALUES(2, 'Product 2');
INSERT INTO ORDER(product_nat_id, name) VALUES(3, 'Product 3');
CREATE TABLE INT_PRODUCT (
product_id INTEGER NOT NULL AUTO_INCREMENT,
product_nat_id INTEGER NOT NULL,
title TINYTEXT,
dateCreate TIMESTAMP CURRENT_TIMESTAMP,
CONSTRAINT INT_PRODUCT_PK PRIMARY KEY (product_id),
UNIQUE INT_PRODUCT_NK (product_nat_id));
But what i want is, whenever a record arrives with an updated value but duplicate key, i need to insert it (and not updated), but avoid duplicate constraint based on the difference in time inserted. Hope this makes sense now.
I would suggest the following:
Look up the previous record. I assume you should know what that would be
SELECT Count(*) FROM dim WHERE recordId = '$recordid'
If in step 1 the records returned are larger than 0 then invalidate the 'previous' record:
UPDATE dim SET datevalid = '$datevalue' where recordId = '$recordid' and status = 2
Continuing with step 1 where the ecords return in the check are larger than 0 now do the insert:
INSERT INTO dim (recordId,field1,field2,date,status) VALUES (1,'sad','123123','2013-03-26',1)
If step 1 was false then just do the insert:
INSERT INTO dim (recordId,field1,field2,date,status) VALUES (1,'sad','123123','2013-03-26',1)
I would add a status field just as an extra measure when you need to find records and distinguish between valid or invalid then you do not need to filter between dates. You can then use the status field. Also have a unique auto-increment key for every record even though the data might be the same for a set of valid and invalid records. recordId and unique key will not be the same in this case. You assign the recordId and the system will assign the unique key on the table. status = 1 is valid and status = 2 is invalid.
Hope this helps!
sample code of your post like as:
Insert query syntax looks like this:
INSERT INTO table (primarykeycol,col1,col2)
VALUES (1,2,3) ON DUPLICATE KEY UPDATE col1=0, col2=col2+1
If there is already a row with primarykeycol set to 1 this query is equal to:
UPDATE table SET col1=0, col2=col2+1 WHERE primarykeycol = 1
explanation as:
Ordinarily to achieve the same result you would have to issue an
UPDATE query, then check if there were affected rows and if not
issue an INSERT query.
This way, you can do everything in one step – first try insert and
then update if insert fails.
One situation for which this type of syntax is perfect is when you
work with daily counters. For example, you might have a table with
PostID, Date and Count columns.
Each day you’d have to check if you already created an entry for
that day and if so increase the count column – and this can be
easily substituted with one INSERT … ON DUPLICATE KEY UPDATE query.
Unfortunately there are some caveats. One being that when you have
multiple unique indexes it will act as if you had an OR condition in
WHERE clause of UPDATE query.
This means that multiple rows should be update, but INSERT … ON
DUPLICATE KEY UPDATE will update only one row.
MySQL manual: INSERT ON DUPLICATE KEY UPDATE Syntax
Im running a database log and every day I log on a new row. My Mysql query therefore checks if the day (date (the unique key)) already exists, and if so, it tries to increment all the loggable values of the log-row by one. If the date record doesnt eyist yet, it will create a new row.
My SQL query is:
INSERT INTO `log` (`date`,`hits`,`stale`)
VALUES ('2012-03-06',1,1)
ON DUPLICATE KEY
UPDATE `hits`=`hits`+1,`stale`=`stale`+1
WHERE `date`='2012-03-06';"
All columns have 0 as default value, so if this query runs directly after midnight only 'stale' and 'hits' are set to 1. Otherwise 'stale' and 'hits' are both incremented.
I wish! (it doesn't work).
What am I missing? Which separator other then a comma should I use between 'hits' = 'hits' +1 and 'stale'='stale'+1?
Just get rid of the WHERE clause:
INSERT INTO `log` (`date`,`hits`,`stale`)
VALUES ('2012-03-06',1,1)
ON DUPLICATE KEY
UPDATE `hits`=`hits`+1,`stale`=`stale`+1;
Your separator is correct, but the UPDATE has already found the duplicate row to be able to trigger the ON DUPLICATE KEY, so you don't need to try to select it again using WHERE.
INSERT INTO `log` (`date`,`hits`,`stale`)
VALUES ('2012-03-06',1,1)
ON DUPLICATE KEY
UPDATE `hits`=`hits`+1,`stale`=`stale`+1
Demo here.
You shouldn't have the WHERE clause. ON DUPLICATE KEY UPDATE automatically limits the row it affects to the one that has the existing key.
Remove it and your query should work fine.
If you only want to do the update if some specific expression is true, you can do it with two statements:
INSERT IGNORE INTO x VALUES (.....);
UPDATE x SET ..... WHERE .....;
The INSERT will silently fail if there is a duplicate key.
In my table I have two fields: v_id and ip_address. I want to insert some data into this table only if the IP address doesn't already exist.
After Google'ing I came across the INSERT IGNORE INTO statement, and this is my code:
public function update_visits($ip_address)
{
$sql = 'INSERT IGNORE INTO `24h_visits` (ip_address) VALUES (?)';
if($this->db->query($sql, array($ip_address)))
{
return TRUE;
}
return FALSE;
}
It runs fine and without errors, but duplicate rows are still being made, even if the same IP is passed in as a parameter.
Anyone got a clue? Thanks.
You have to create a UNIQUE index on ip_address for INSERT IGNORE to work:
ALTER TABLE 24h_visits
ADD UNIQUE INDEX(ip_address)
However, I haven't seen the entirety of your schema, but I would assume that there's a column that stores a timestamp of the last visit. It's the only way this would make sense (so you can purge visits older than 24 hours every now and then).
In this case, you actually don't want INSERT IGNORE, but INSERT ... ON DUPLICATE KEY UPDATE instead. Assuming you have a column called last_visit:
INSERT INTO 24h_visits (ip_address, last_visit)
VALUES ('$ip_address', NOW())
ON DUPLICATE KEY UPDATE last_visit = NOW();
With INSERT IGNORE, the new row is never inserted, and thus you would always have the first value ever inserted on last_visit, which (the way I see it) is not entirely correct.
Add the UNIQUE constraint to your ip_address column.
Then your query would fail if it attempts to add a duplicate ip_address row (unless you use INSERT IGNORE).
The other answers don't actually answer the question: Creating a unique index prevents the duplicate from being inserted, which is a good idea, but it doesn't answer "how to insert if not already there".
This is how you do it:
INSERT IGNORE INTO 24h_visits (ip_address)
select ?
where not exists (select * from 24h_visits where ip_address = ?)
Additionally, this approach does not require any changes to schema.