By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content, updating the mysql table if query store_num exits, Is it faster to insert duplicate value in unique column or first check is it already inserted, bulk INSERT on DUPLICATE KEY UPDATE with 50+ columns, MySQL query - if not exists - insert into - else - update, Check for the respective data in a specific column and if not detected, then insert. Did neanderthals need vitamin C from the diet? Why does the distance from light to subject affect exposure (inverse square law) while from subject to lens does not? SELECT stateID, MAX(city.pop) as largestCityPop, state.pop FROM city You can use a CASE expression: INSERT INTO users (user_id, books) VALUES (1, 'book1, book2'), (2, 'book3, book4') ON DUPLICATE KEY UPDATE books = CASE user_id WHEN 1 THEN 'book10, book20' WHEN 2 THEN 'book30, book40' END; Your email address will not be published. In this situation the REPLACE could fail or worse: if your foreign key is set to cascade delete, the REPLACE will cause rows from other tables to be deleted. not using REPLACE INTO or ON DUPLICATE KEY UPDATE, http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html. You can avoid this by putting the UPDATE and INSERT in the same transaction. Asmentioned before, replace into .. will delete the duplicate rows before inserting, so when the replace into t1(a,b,c) values (2,1,9); is executing, it checks the primary key first, its duplicated, so the (2,2,2) is deleted, then the column b is also duplicated, so the (3,1,2) is deleted, after that, no duplicate key exists, then insert a new row (2,1,9). The chance of collision can though be considered 50/50. biggestCityPop. What is the difference between INSERT IGNORE and INSERT ON DUPLICATE KEY UPDATE in MySQL? Join the DZone community and get the full member experience. This one 0. Making statements based on opinion; back them up with references or personal experience. Insert on Duplicate Key Update: 2.446 seconds, Table Size: 1,249,250 rows with 12 columns on an Amazon m3.medium. In what particular cases can REPLACE be preferred over INSERT ON IF NOT EXISTS (QUERY) Then INSERT. Instead of acting as update this really will insert NULL value, as col1 is undefined at this stage. ON DUPLICATE KEY UPDATE . A user tried to edit this post (the edit was rejected by moderators). main task was check the quickly the site product table and check with If 1 fails, delete row and insert new row Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. It will cause the DUPLICATE KEY UPDATE largestCityPop = MAX(city.pop). Is IntelliJ Making Us Stupid? 2. mysql update query almost 5 minutes slower in 5.6 vs 5.5. What are the other practical differences to take in mind? Asking for help, clarification, or responding to other answers. This is because a row was inserted after the duplicate row was deleted.. SQL Server Update Statement joining on index column. ON DUPLICATE KEY UPDATE" (Code Answer) . What are practical differences between `REPLACE` and `INSERT ON DUPLICATE KEY UPDATE` in MySQL? state.pop FROM city JOIN state on city.stateID = state.ID GROUP BY city.stateID) x ON DUPLICATE KEY UPDATE largestCityPop = It's true that the new id is generated, but it is not used in the changed row.. See demonstration below, tested with Percona Server 5.5.28. SELECT * FROM (SELECT stateID, MAX(city.pop) as biggestCityPop, Why Does the Update Statement also updates indexes? Are the S&P 500 and Dow Jones Industrial Average securities? Code language: SQL (Structured Query Language) (sql) Try It. The 49ers turned to Jimmy Garoppolo early this season after initial starter Trey Lance suffered a season-ending ankle injury. If it finds an By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. ; Code language: SQL (Structured Query Language) (sql) Here, if the value specified in the. Bracers of armor Vs incorporeal touch attack. The atomicity of the latter (in addition to not causing cascade deletes) is all the more reason to use it. DUPLICATE KEY UPDATE largestCityPop = city.largestCityPop, INSERT IGNORE INTO largestCities (stateID, largestCityPop, statePop) Answer (1 of 2): Replace Into involves: 1. Insert on Duplicate Key Update involves: Replace Into: 77.411 seconds Why does the distance from light to subject affect exposure (inverse square law) while from subject to lens does not? Received a 'behavior reminder' from manager. did anything serious ever run on the speccy? Would salt mines, lakes or flats be reasonably found in high, snowy elevations? Or you can check with. ON DUPLICATE KEY UPDATE clause to the INSERT function. Making statements based on opinion; back them up with references or personal experience. Why is it so much harder to run on a treadmill when not holding the handlebars? Is this an at-all realistic configuration for a DHC-2 Beaver? How to say "patience" in latin in the modern sense of "virtue of waiting or being able to wait"? Improving performance of insert..on duplicate key update, How to update primary key table based on foreign key with ON DUPLICATE KEY UPDATE. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. existing one, you specify a clause for which column(s) you would like to UPDATE. So the other half of the question: when would you prefer. REPLACE seems to be necessary sometimes because INSERT IGNORE doesn't seem to work with data transformations. So I decided to TEST both methods in my application and using the actual database. Connect and share knowledge within a single location that is structured and easy to search. Also for some reason it shows the query as an INSERT operation, even though an UPDATE is performed: Also, by running the query in phpmyadmin, for some reason it shows that 2 rows have been INSERTed, while in fact only 1 row was UPDATEd with the data: Bottom line is, which operation would be the fastest in terms of code optimization? INSERT ON DUPLICATE KEY UPDATE is newer feature which came in . So we got the new line (2,2,4) instead of (2,3,4). Replace aduplicate primary key and a duplicate unique key at the same time: After replace into , it shows 3 rows affected, two rows have been deleted and just one row is inserted into t1. If more than one unique index is matched . ON DUPLICATE KEY UPDATE . If 1 fails, delete row and insert new row We will be using this table to do this operation: INSERT INTO upsert_example (ID, Name, Alias, Status) VALUES (4,'May', 'black', 'Alive') ON DUPLICATE KEY UPDATE Status = 'Deceased', Alias = 'Aunt'; So here we can see that the exact column value is updated, unlike REPLACE which deletes the entire record and updates the new record in the name of . While me and my friend roshan recently working as a support If you didnt specify the column name, for example: Column a and c have been changed into 3 and null, so when using replace into, it will delete the duplicate row and insert a new rowwith the default value. replace into INSERT . Are defenders behind an arrow slit attackable? Unless there's some particular reason why your code relies on rows being deleted and re-added, with the associated effects on indexes and auto-increment values, there doesn't appear to be any reason to use it. In that case, the most often operations are the UPDATEs, however in the first case, there is that little overhead of an extra db call, if any, of checking if an UPDATE has actually happened, which is what I'd like to remove. Both methods have been ran on actual data 20 times with at least 5 seconds gap between tests: So as to answer my own doubt, at least in case of UPDATES, using the 1st method is the winner, though the 2nd one isn't bad either. If 1 fails, update row If all the steps involved are inserts, there should be no difference in performance. When using REPLACE instead of INSERT ON DUPLICATE KEY UPDATE, I sometimes observe key locking or deadlock problems when multiple queries arrive quickly for a given key. . JOIN state on city.stateID = state.ID GROUP BY city.stateID ON If all the steps involved are inserts, there should be no difference in performance. JOIN state on city.stateID = state.ID GROUP BY city.stateID ON UNIQUE or PRIMARY KEY as the one were trying to update. If 1 fails, delete row and insert new row Insert on Duplicate Key Update involves: 1. INSERT INTO t1 (a,b,c) VALUES (1,2,3), (4,5,6) ON DUPLICATE KEY UPDATE c=VALUES (a)+VALUES (b); That statement is identical to the following two statements: INSERT INTO t1 (a,b,c) VALUES (1,2,3) ON DUPLICATE KEY UPDATE c=3; INSERT INTO t1 (a,b,c) VALUES (4,5,6) ON DUPLICATE KEY UPDATE c=9; For INSERT. Why is apparent power not measured in Watts? Is Energy "equal" to the curvature of Space-Time? After we used replace into on the unique key, the (1,1,2) was deleted and a new row (3,1,9) wasinserted, its not just replaced values at the (1,1,2) row because the column a used theAUTO_INCREMENT value 3. Find centralized, trusted content and collaborate around the technologies you use most. What happens if you score more than 99 points in volleyball? Why does my stock Samsung Galaxy phone/tablet lack some features compared to other Samsung Galaxy models? Using INSERT ON DUPLICATE KEY UPDATE avoids this problem and is therefore prefered. It only takes a minute to sign up. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. REPLACE internally performs a delete and then an insert. Making statements based on opinion; back them up with references or personal experience. Why does the USA not have a constitutional court? The speed . ON DUPLICATE KEY UPDATE Syntax. Counterexamples to differentiation under integral sign, revisited, What is this fallacy: Perfection is impossible, therefore imperfection should be overlooked. Otherwise update, INSERTON DUPLICATE KEY when updating a table, SQL/JAVA: Upon attempting to save data to tables will not add to tables. Is Energy "equal" to the curvature of Space-Time? The update query was using the INDEX. Perhaps that implies there is a speed difference between the two? Help us identify new roles for community members, On duplicate key update VS single query multiple updates, Trouble with triggers and insert .. on duplicate key update, Unique insert performance: Primary Key vs Unique Index, MSG 666 when running an insert query on 80M-row indexed table. SELECT stateID, MAX(city.pop) as largestCityPop, state.pop FROM city Order by is ignored if inside a derived table of a update (only in MYSQL 5.7) 0. From the docs: http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html, you only have to use a unique key field. A Guide to Machine Learning App Development. In-person at a Department of Public Safety office. Replace Into involves: 1.Try insert on the table 2. ON DUPLICATE KEY UPDATE which implies an unnecessary update at some cost, or; . Ready to optimize your JavaScript with Rust? Asking for help, clarification, or responding to other answers. INSERT INTO table (colsList) VALUES ( values ) ON DUPLICATE KEY UPDATE col =newValue . Over the phone. This can cause problems if you have a foreign key constraint pointing at that row. To learn more, see our tips on writing great answers. If I do this, I only set largestCityPop to itself: INSERT IGNORE INTO largestCities (stateID, largestCityPop, statePop) What Is the Fastest Way to Solve a Machine Learning Problem? ON DUPLICATE KEY UPDATE. Opinions expressed by DZone contributors are their own. The problem with REPLACE was - many people tried to use it like update accessing previous column value, for example doing something like REPLACE INTO tbl (col1) VALUES (col1+10);. Get the new record primary key ID from MySQL insert query? Not the answer you're looking for? Solution 1 I would recommend using INSERT.ON DUPLICATE KEY UPDATE. REPLACE internally performs a delete and then an insert. "INSERT IGNORE" vs "INSERT . Die Bearbeitung versuchte, eine Behauptung hinzuzufgen, dass INSERT.ON DUPLICATE KEY UPDATE dazu fhrt, dass eine neue Auto-Increment-ID zugewiesen wird. What is the difference between UNION and UNION ALL? How does legislative oversight work in Switzerland when there is technically no "opposition" in parliament? Asking for help, clarification, or responding to other answers. Fortunately, I was able to use REPLACE instead of INSERTON DUPLICATE KEY UPDATE within my after insert trigger to achieve the desired outcome of replicating changes to a FEDERATED table. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Inserting a NULL into a column with a NOT NULL constraint. 2. Insert into on duplicate key query for custom update on each row. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Is it cheating if the proctor gives a student the answer key by mistake and the student doesn't report it? The column that I need to test is not the primary key, it holds an email address. How to set a newcommand to be incompressible by justification? The reason I uses the id column to refer to the session data rather than the email column is because the email is entered by the user who has no idea about the id columns existence. . ", http://dev.mysql.com/doc/refman/5.7/en/replace.html. Using INSERT ON DUPLICATE KEY UPDATE avoids this problem and is therefore prefered. In MySQL using InnoDB, which is better for performance: REPLACE INTO or INSERT ON DUPLICATE KEY UPDATE? The insert on duplicate key update just checked the primary key, and after found the primary key a had a duplicate value 2, then it updated the column c to new value 4, and ignored the column b which was also duplicate. Something can be done or not a fit? MySQL error code: 1175 during UPDATE in MySQL Workbench, Storing JSON in database vs. having a new column for each key. And as. On the other hand, it's the reverse of checking for an INSERT else UPDATE which would be true all the times, but with the advantage of only 1 db query. The code here is just an example with actual values for understanding context. then an INSERT, or just an INSERT if use this this function will cause a And if I do this, MySQL won't recognize the column name: INSERT IGNORE INTO largestCities (stateID, largestCityPop, statePop) Whereas REPLACE does delete the original row and inserts a new row, generating and storing a new auto-increment id: In my recent work, i found that there were some traps when using them, and this article is to show what will happen and why. Ready to optimize your JavaScript with Rust? Sudo update-grub does not work (single boot Ubuntu 22.04). Ein Benutzer hat versucht, diesen Beitrag zu bearbeiten (die Bearbeitung wurde von den Moderatoren abgelehnt). either updating or inserting would be an expensive process (existing ". Doing just 20 rows isn't very accurate. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, From a manual page I found somewhere: "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. I want to be able to quit Finder but can't edit Finder's Info.plist after disabling SIP, Penrose diagram of hypothetical astrophysical white hole. Thanks a lot for clearing that up! Database Administrators Stack Exchange is a question and answer site for database professionals who wish to improve their database skills and learn from others in the community. The row/s affected value is reported as 1 if a row is inserted, and 2 if a row is updated, unless the API's CLIENT_FOUND_ROWS flag is set. Better way to check if an element only exists in one array. In MYSQL how do I update (not replace) a row if it exists else create a new row. "INSERT IGNORE" vs "INSERT ON DUPLICATE KEY UPDATE". assign a new bug in this site its related to the product synchronize ON DUPLICATE KEY UPDATE, it'll update the values of all the fields while keeps the value of the email untouched: After running. Thanks a lot for clearing that up! WHERE id <= 10000, but this only works if you realy have to update 10000 rows with . We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, I get this: #1170 - BLOB/TEXT column 'email' used in key specification without a key length. If you see the "cross", you're on the right track, Typesetting Malayalam in xelatex & lualatex gives error. http://www.tokutek.com/2010/07/why-insert-on-duplicate-key-update-may-be-slow-by-incurring-disk-seeks/. Books that explain fundamental chess concepts. What should I choose then? Am I right? I'm using prepared statements already. ". Check Out Most Asked MySQL Questions and Answers . I see that for some reason you do not want a unique email-column. If, however. developers at Australia famous e-commerce website. 1.Try insert on the table Find centralized, trusted content and collaborate around the technologies you use most. Connect and share knowledge within a single location that is structured and easy to search. With ON DUPLICATE KEY UPDATE, mysql_affected_rows() is 1 if the row is inserted as a new one and 2 if an existing row is updated. What I need is to set the values of all the fields of a record with a particular key (the key is composite actually), inserting the record if there is no record with such a key yet. INSERT ON DUPLICATE KEY UPDATE and REPLACE INTO. 4. ON DUPLICATE KEY UPDATE clause to the INSERT function. This is because a row was inserted after the . Syntax : INSERT INTO table (column_names) VALUES (values) ON DUPLICATE KEY UPDATE col1 = val1, col2 = val2 ; Along with the INSERT statement, ON DUPLICATE KEY UPDATE statement defines a list of column & value assignments in case of duplicate. The above demonstrates that the IODKU statement detects the duplicate, and invokes the update to change the value of u.Note the AUTO_INCREMENT=3 indicates an id was generated, but not used in the row. After 'replace into ', it shows '3 rows affected ', two rows have been deleted and just one row is inserted into t1. What of them should I better choose and why? How can I return pivot table output in MySQL? How to use a VPN to access a Russian website that is banned in the EU? Add a new light switch in line with another switch? How do I tell if this single climbing rope is still safe for use? Does the collective noun "parliament of owls" originate in "parliament of fowls"? INSERT INTO t1 (a,b,c) VALUES (1,2,3) ON DUPLICATE KEY UPDATE c=c+1; UPDATE t1 SET c=c+1 WHERE a=1; items are defined either by a unique key or a primary key). record to be removed, and inserted at the end. 2. MySQL-MariaDB. What the statement tried to do is to update the min_salary for the position with id 2, which is the developer.. First, the position with id 2 already exists, the REPLACE statement removes it.. Then, SQLite tried to insert a new row with two columns: ( id, min_salary).However, it violates the NOT NULL constraint of the title column. DUPLICATE KEY UPDATE and vice versa? REPLACE INTO ds_product SET pID = 3112, catID = 231, uniCost = 232.50, salePrice = 250.23; 2. Not for the record being updated, but for the next record inserted. This can happen even though the constraint was satisfied both before and after the REPLACE operation. Did you see that you can have multi-column unique indeces? Otherwise, it will do a normal INSERT. I've done a fair bit of research and as far as I can tell, there is no common reason to use REPLACE instead of INSERT ON DUPLICATE KEY UPDATE. Insert on Duplicate Key update is almost 32 times faster in my case replace into INSERT . When you use a REPLACE command, mysql_affected_rows() will return 2 if the new row replaces an old row. In a word, before using replace into and insert into on duplicate key update , you must know what they actually do, otherwise you will get unexpected results. Connecting three parallel LED strips to the same power supply, MOSFET is getting very hot at high frequency PWM. In the performed test, I'll refer to "METHOD 1" as the one in which we check for affected rows and insert if necessary, and subsequently refer to "METHOD 2" as using INSERT INTO.. ON DUPLICATE KEY UPDATE. The edit tried to add a claim that INSERT.ON DUPLICATE KEY UPDATE causes a new auto-increment id to be allocated. As for REPLACE: REPLACE Syntax. Thank you. Try insert on the table 2. Try insert on table 2. Good answer, but in the actual case of mine this problem is not going to be met. . If, for example, you had a unique index over email and timestamp, you could use ON DUPLICATE KEY UPDATE. Yes, any SQL-buildt-in update/replace method that can fall back to insert needs a unique field. When dealing with a Solution 7. What is the difference between "INNER JOIN" and "OUTER JOIN"? Debian/Ubuntu - Is there a man page listing all the version codenames/numbers? So if the highest ID is 10 and you do a duplicate insert, and then inserts a new unique value, that row' s ID will become 12. Insert into a MySQL table or update if exists, MySQL LOAD DATA INFILE with ON DUPLICATE KEY UPDATE. Comment document.getElementById("comment").setAttribute( "id", "a437e5e3e1754c945cd9f60ea2d74361" );document.getElementById("a647284630").setAttribute( "id", "comment" ); Tips when using replace into and insert on duplicate key update in MySQL. With ON DUPLICATE KEY UPDATE, mysql_affected_rows() is 1 if the row is inserted as a new one and 2 if an existing row is updated. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content, MySQL error: key specification without a key length, "INSERT IGNORE" vs "INSERT ON DUPLICATE KEY UPDATE", Does SQL Server Offer Anything Like MySQL's ON DUPLICATE KEY UPDATE, Insert into a MySQL table or update if exists. (Keep transactioning in mind). We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. In what particular cases can REPLACE be preferred over INSERT ON DUPLICATE KEY UPDATE and vice versa? To learn more, see our tips on writing great answers. Find and Replace text in the entire table using a MySQL query. Thanks for contributing an answer to Stack Overflow! rev2022.12.9.43105. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. recently roshan as Is the EU Border Guard Agency able to tell Russian passports issued in Ukraine or Georgia from the legitimate ones? This can happen even though the constraint was satisfied both before and after the REPLACE operation. rev2022.12.9.43105. INSERT ON DUPLICATE UPDATE is what I need to use, especially knowing the cascading keys issue. Oh, that explains it then. Required fields are marked *. MySQL performance issue - intermittently slow queries. basically I have a table that stores emails and other random data. When would I give a checkpoint to my D&D party that they can return to if they die? Why is Singapore considered to be a dictatorial regime and a multi-party democracy at the same time? Cannot insert duplicate key row on a non-unique index? 1.Try insert on table A user tried to edit this post (the edit was rejected by moderators). site database, or update an existing record on the site database, Of I know I was just asking what was faster and looks like update is. replace. Alright so I have this table in which until now I was using the following queries to UPDATE else do an INSERT: I had a regular combined index (non-unique) on uid&date columns. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. If email comes first in the order of the 2 columns, it even substitutes for the non-unique email-only index. BTW, in stead of worrying about an extra db call, I'd worry about not using bind variables and prepared statements. 1. insert into on duplicate key updatereplace into (). As mentioned before, 'replace into ..' will delete the duplicate rows before inserting, so when the 'replace into t1(a,b,c) values (2,1,9);' is executing, it checks the primary key first, it's duplicated, so the (2,2,2) is deleted, then the column 'b' is . Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. 2. A small bolt/nut came off my mtn bike while washing it, can someone help me identify it? By mail. REPLACE internally performs a delete and then an insert. SELECT and UPDATE in a single query while updating selective fields of duplicate records only. Thanks for contributing an answer to Database Administrators Stack Exchange! MySQL: INSERT ON DUPLICATE KEY UPDATE not all the fields. Replace Into seems like an option. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Over 2 million developers have joined DZone. Worst case is when all the statements are updates, I have tried both the statements on my InnoDB table involving 62,510 entries (only updates). This is different with replace into .., it just updates the value on the duplicate row, with no deletion. It's Complicated, Difference Between Mysql Replace and Insert on Duplicate Key Update. Oh, that explains it then. To answer the question in terms of performance, I did a test using both the methods, Replace Into involves: Sometimes when we want to insert rows into a table which contains duplicate keys, then we consider using replace into or insert into on duplicate key update . Should I give a brutally honest feedback on course evaluations? actively hunts down an existing record in the table which has the same A real pity, there's really no need for more bad examples. It's essentially a legacy feature. ware house product table product if the either insert new data into a Get the new record primary key ID from MySQL insert query? 5.1ID1. Well, according to this blog post anyway http://www.tokutek.com/2010/07/why-insert-on-duplicate-key-update-may-be-slow-by-incurring-disk-seeks/, "It is possible that in the case of a duplicate-key error, a storage engine may perform the REPLACE as an update rather than a delete plus insert, but the semantics are the same. I reference the rows as saved sessions by the primary-unique-auto-incriminating-number column (id). auto_increment+1replace into+1insert on deplicate udpate . This will insert or delete then insert. Driver license and ID, renewals, and replacements. How do I tell if this single climbing rope is still safe for use? If you specify an ON DUPLICATE KEY UPDATE clause and a row to be inserted would cause a duplicate value in a UNIQUE index or PRIMARY KEY, an UPDATE of the old row occurs. 3. The rubber protection cover does not pass through the hole in the rim. @BENZ.404 What is a data type of your email column? This can cause problems if you have a foreign key constraint pointing at that row. REPLACE seems as meant to do the job, but at the same time its manual page suggests Your email address will not be published. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. I've just found out the hard way that in the case of tables with a FEDERATED storage engine INSERTON DUPLICATE KEY UPDATE statements are accepted, but fail (with an Error 1022: Can't write; duplicate key in table) if a duplicate-key violation occurs - see corresponding bullet point on this page of the MySQL Reference Manual. Does balls to the wall mean full speed ahead or full speed ahead and nosedive? The fastest operation will be the one that has the most chances of succeeding immediately. To update a non-unique-field, youll have to use a where-condition and check if any rows has been altered. All is fine but I was wondering if switching to ON DUPLICATE KEY UPDATE would be better, especially as the two columns' INDEX can be switched to UNIQUE. Replace seems that it does two operations in the case that the key already exists. Does balls to the wall mean full speed ahead or full speed ahead and nosedive? SELECT FROM . in the second query you insert only 10000 rows, check the key by index and update the rows. Code accordingly. replace into . Connect and share knowledge within a single location that is structured and easy to search. approaches). . rev2022.12.9.43105. Maybe mysql checks in the first query mysql checks 17 million rows, if one fit in the IN clause. Interesting point which adds another reason to rather use INSERT INTO ON DUPLICATE KEY UPDATE instead as that would eliminate the risk of colliding inserts. Does integrating PDOS give total charge of a system? When you use a REPLACE command, mysql_affected_rows() will return 2 if the new row replaces an old row.This is because a row was inserted after the .. With ON DUPLICATE KEY UPDATE, mysql_affected_rows . INSERT ON DUPLICATE KEY UPDATE = UPDATE + INSERT, This syntax is the same as the INSERT function. this seems require comparison of a unique key (id) which is not what I need it would be better if I could do something like: or something like this (but I don't think it is valid MYSQL): Actually, you answered your question yourself: 1. The edit tried to add a claim that INSERT.ON DUPLICATE KEY UPDATE causes a new auto-increment id to be allocated.It's true that the new id is generated, but it is not used in the changed row. I assume that the duplicate key is the column user_id. So I went ahead and modified the INDEX to an UNIQUE one, then rewrote the query as follows: However, mysql explain is showing that the INDEX is not used in this case. Ready to optimize your JavaScript with Rust? To use the values from the INSERT clause in the DUPLICATE KEY UPDATE clause, you use the VALUES function as follows: INSERT INTO table_name (c1) VALUES (c1) ON DUPLICATE . This should be helpful when trying to create database queries that Differences between INDEX, PRIMARY, UNIQUE, FULLTEXT in MySQL? I'd try with much more load, say 20K inserts. In this situation the REPLACE could fail or worse: if your foreign key is set to cascade delete, the REPLACE will cause rows from other tables to be deleted. Luckily, This one actively . But I get the error when I try to make email unique how can it work if I get this error?? ON DUPLICATE KEY UPDATE is a MariaDB/MySQL extension to the INSERT statement that, if it finds a duplicate unique or primary key, will instead perform an UPDATE. Each renewal method has different eligibility requirements. With ON DUPLICATE KEY UPDATE, mysql_affected_rows() is 1 if the row is inserted as a new one and 2 if an existing row is updated.As for REPLACE: REPLACE Syntax. October 31, 2018 INSERT ON DUPLICATE KEY UPDATE does in fact also increment the autoincrement counter. From a manual page I found somewhere: "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. indexing to get broken apart, decreasing the efficiency of the table. I tend to go for a IF NOT EXISTS check first. I mean, if you transform the email field as an unique field, running: now, when you try to insert a row with the same email, using INSERT ON DUPLICATE KEY UPDATE, it'll update the values of all the fields while keeps the value of the email untouched: Keep an eye on specify which fields you want to be updated, if you don't specify them, it won't be updated! correction: both REPLACE and INSERT.ON DUPLICATE KEY UPDATE are non-standard, proprietary inventions . The diff 0f 7% is only 0.03 milliseconds. Thanks for contributing an answer to Stack Overflow! INSERT INTO.SELECT for all MySQL columns. Well, I tried with ~864000 inserts and INSERT INTO ON KEY DUPLICATE UPDATE is the fastest, much more than UPDATE :), UPDATE vs INSERT INTO ON DUPLICATE KEY UPDATE. Why did the Council of Elrond debate hiding or sending the Ring away, if Sauron wins eventually in that scenario? add and update information, without having to go through the extra step. You can renew your Texas driver license or ID card: Online. EDIT: And the reason why I am not refering to the session by the email is because emails are too/different lengths (long story but they make my QR Codes all different sizes and I don't wan't to expose emails), this looks like it will destroy my id number as this method copies the row while it removes the old. The only "side effect" of REPLACE that comes into my mind is that it would increment autoincrement values (fortunately I don't use any) while INSERT ON DUPLICATE KEY UPDATE probably wouldn't. INSERT INTO . ON DUPLICATE KEY UPDATE Syntax. How does the Chameleon's Arcane/Divine focus interact with magic item crafting? How could my characters be tricked into thinking they are on Mars? Not the answer you're looking for? This can cause problems if you have a foreign key constraint pointing at that row. At what point in the prequels is it revealed that Palpatine is Darth Sidious? Now, they're turning to rookie Brock Purdy after Garoppolo suffered . Still can't decide You wouldn't happen to have a coin with heads on both sides? Shuo Wang MySQL offers two functions to combat this (each with two very different record with a unique or primary key, REPLACE will either do a DELETE and Not sure if it was just me or something she sent to the whole team. (INSERT)one update vs one delete + one insert(REPLACE), EDIT: My implication that replace might be slower is actually completely wrong. ON DUPLICATE KEY UPDATE. ON DUPLICATE KEY UPDATE will leave unmentioned columns unchanged. As for REPLACE: REPLACE Syntax When you use a REPLACE command, mysql_affected_rows() will return 2 if the new row replaces an old row. The speed has to depend on the number of updates involved. See demonstration below, tested with Percona Server 5.5.28. If you use INSERT IGNORE, then the row won't actually be inserted if it results in a duplicate key. INSERT ON DUPLICATE KEY UPDATE. Debian/Ubuntu - Is there a man page listing all the version codenames/numbers? EDIT: Now, with a SQLFiddle to show it working: http://sqlfiddle.com/#!2/79e67/3. Counterexamples to differentiation under integral sign, revisited, Penrose diagram of hypothetical astrophysical white hole. Disconnect vertical tab connector from PCB. SELECT stateID, MAX(city.pop) as largestCityPop, state.pop FROM city If you don't list all the columns, I think REPLACE will reset any unmentioned columns with their default values in the replaced rows. course, doing a lookup to see if the record exists already and then After some research, my options appear to be the use of either: ON DUPLICATE KEY UPDATE which implies an unnecessary update at some cost, or INSERT IGNORE implies an invitation for other kinds of failure to slip in unannounced. Es ist wahr, dass die neue ID lautet erzeugt wird, aber sie wird nicht in der genderten Zeile verwendet. process in the ware house product table and the e-commerce site, his Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. For example, if column a is declared as UNIQUE and contains the value 1, the following two statements have similar effect: . If this is the case you could try to rewritee the first query to UPDATE. If I do this, I am using the GROUP function improperly: INSERT IGNORE INTO largestCities (stateID, largestCityPop, statePop) While executing an INSERT statement with many rows, I want to skip duplicate entries that would otherwise cause failure. DUPLICATE KEY UPDATE largestCityPop = largestCityPop. 2.If 1 fails, update row INSERT INTO my_table ( a, b, email ) VALUES ( 2, 2, '[email protected]' ) on duplicate key update a=VALUES (a), b=VALUES (b) Keep an eye on specify which fields you want to be updated, if you don't specify them, it . How to use ON DUPLICATE KEY UPDATE in MySQL without a UNIQUE index or PRIMARY KEY? On camparing speeds: Learn which renewal method is right for you. Why is apparent power not measured in Watts? JOIN state on city.stateID = state.ID GROUP BY city.stateID ON 1replace into 2, on duplicate key update "" 12 Is the EU Border Guard Agency able to tell Russian passports issued in Ukraine or Georgia from the legitimate ones? You should find out what happens more often: inserting new rows or updating old ones. To learn more, see our tips on writing great answers. If there are multiple threads and uid / date is unique, there could be a risk that the INSERTs could collide. 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