replace into vs on duplicate key update

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. DUPLICATE KEY UPDATE largestCityPop = largestCityPop. 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 . Order by is ignored if inside a derived table of a update (only in MYSQL 5.7) 0. Thank you. Should I give a brutally honest feedback on course evaluations? record to be removed, and inserted at the end. What is the difference between INSERT IGNORE and INSERT ON DUPLICATE KEY UPDATE in MySQL? Why is it so much harder to run on a treadmill when not holding the handlebars? ON DUPLICATE KEY UPDATE Syntax. If there are multiple threads and uid / date is unique, there could be a risk that the INSERTs could collide. In MYSQL how do I update (not replace) a row if it exists else create a new row. MySQL-MariaDB. Is IntelliJ Making Us Stupid? While executing an INSERT statement with many rows, I want to skip duplicate entries that would otherwise cause failure. The diff 0f 7% is only 0.03 milliseconds. Is Energy "equal" to the curvature of Space-Time? developers at Australia famous e-commerce website. What is the difference between "INNER JOIN" and "OUTER JOIN"? 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. ON DUPLICATE KEY UPDATE will leave unmentioned columns unchanged. ON DUPLICATE KEY UPDATE. state.pop FROM city JOIN state on city.stateID = state.ID GROUP BY actively hunts down an existing record in the table which has the same Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. Ready to optimize your JavaScript with Rust? Did you see that you can have multi-column unique indeces? Something can be done or not a fit? In what particular cases can REPLACE be preferred over INSERT ON DUPLICATE KEY UPDATE and vice versa? For example, if column a is declared as UNIQUE and contains the value 1, the following two statements have similar effect: . either updating or inserting would be an expensive process (existing Not sure if it was just me or something she sent to the whole team. Get the new record primary key ID from MySQL insert query? While me and my friend roshan recently working as a support site database, or update an existing record on the site database, Of Opinions expressed by DZone contributors are their own. 0. If you use INSERT IGNORE, then the row won't actually be inserted if it results in a duplicate key. How can I return pivot table output in MySQL? Received a 'behavior reminder' from manager. 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; I'm using prepared statements already. ON DUPLICATE KEY UPDATE. in the second query you insert only 10000 rows, check the key by index and update the rows. 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. 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. Solution 1 I would recommend using INSERT.ON DUPLICATE KEY UPDATE. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. 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 . Why did the Council of Elrond debate hiding or sending the Ring away, if Sauron wins eventually in that scenario? Find centralized, trusted content and collaborate around the technologies you use most. Or you can check with. This can cause problems if you have a foreign key constraint pointing at that row. 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. 4. A user tried to edit this post (the edit was rejected by moderators). Is Energy "equal" to the curvature of Space-Time? DUPLICATE KEY UPDATE and vice versa? What of them should I better choose and why? SELECT stateID, MAX(city.pop) as largestCityPop, state.pop FROM city MySQL: INSERT ON DUPLICATE KEY UPDATE not all the fields. 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. (INSERT)one update vs one delete + one insert(REPLACE), EDIT: My implication that replace might be slower is actually completely wrong. 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. 1. insert into on duplicate key updatereplace into (). Inserting a NULL into a column with a NOT NULL constraint. The 49ers turned to Jimmy Garoppolo early this season after initial starter Trey Lance suffered a season-ending ankle injury. 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 . ON DUPLICATE KEY UPDATE, it'll update the values of all the fields while keeps the value of the email untouched: After running. So the other half of the question: when would you prefer. If I do this, I am using the GROUP function improperly: INSERT IGNORE INTO largestCities (stateID, largestCityPop, statePop) Answer (1 of 2): Replace Into involves: 1. did anything serious ever run on the speccy? http://www.tokutek.com/2010/07/why-insert-on-duplicate-key-update-may-be-slow-by-incurring-disk-seeks/. Replace Into involves: 1.Try insert on the table 2. 2. mysql update query almost 5 minutes slower in 5.6 vs 5.5. If I do this, I only set largestCityPop to itself: INSERT IGNORE INTO largestCities (stateID, largestCityPop, statePop) Not the answer you're looking for? When dealing with a If 1 fails, delete row and insert new row Insert on Duplicate Key Update involves: 1. 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 . Es ist wahr, dass die neue ID lautet erzeugt wird, aber sie wird nicht in der genderten Zeile verwendet. JOIN state on city.stateID = state.ID GROUP BY city.stateID ON The chance of collision can though be considered 50/50. Connect and share knowledge within a single location that is structured and easy to search. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. correction: both REPLACE and INSERT.ON DUPLICATE KEY UPDATE are non-standard, proprietary inventions . To subscribe to this RSS feed, copy and paste this URL into your RSS reader. WHERE id <= 10000, but this only works if you realy have to update 10000 rows with . REPLACE INTO ds_product SET pID = 3112, catID = 231, uniCost = 232.50, salePrice = 250.23; 2. 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). rev2022.12.9.43105. 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. Is the EU Border Guard Agency able to tell Russian passports issued in Ukraine or Georgia from the legitimate ones? It's Complicated, Difference Between Mysql Replace and Insert on Duplicate Key Update. Does integrating PDOS give total charge of a system? REPLACE internally performs a delete and then an insert. Improving performance of insert..on duplicate key update, How to update primary key table based on foreign key with ON DUPLICATE KEY UPDATE. Find centralized, trusted content and collaborate around the technologies you use most. 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. Books that explain fundamental chess concepts. I reference the rows as saved sessions by the primary-unique-auto-incriminating-number column (id). replace into INSERT . Each renewal method has different eligibility requirements. Luckily, After 'replace into ', it shows '3 rows affected ', two rows have been deleted and just one row is inserted into t1. Am I right? How to use a VPN to access a Russian website that is banned in the EU? INSERT INTO . By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Is this an at-all realistic configuration for a DHC-2 Beaver? 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. What are practical differences between `REPLACE` and `INSERT ON DUPLICATE KEY UPDATE` in MySQL? UPDATE. 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. To update a non-unique-field, youll have to use a where-condition and check if any rows has been altered. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. Better way to check if an element only exists in one array. ; Code language: SQL (Structured Query Language) (sql) Here, if the value specified in the. REPLACE internally performs a delete and then an insert. In MySQL using InnoDB, which is better for performance: REPLACE INTO or INSERT ON DUPLICATE KEY UPDATE? If you don't list all the columns, I think REPLACE will reset any unmentioned columns with their default values in the replaced rows. This one actively . 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). main task was check the quickly the site product table and check with And if I do this, MySQL won't recognize the column name: INSERT IGNORE INTO largestCities (stateID, largestCityPop, statePop) The column that I need to test is not the primary key, it holds an email address. If it finds an 3. On camparing speeds: Get the new record primary key ID from MySQL insert query? Over the phone. SELECT and UPDATE in a single query while updating selective fields of duplicate records only. Differences between INDEX, PRIMARY, UNIQUE, FULLTEXT in MySQL? Join the DZone community and get the full member experience. October 31, 2018 Insert on Duplicate Key Update: 2.446 seconds, Table Size: 1,249,250 rows with 12 columns on an Amazon m3.medium. Why is Singapore considered to be a dictatorial regime and a multi-party democracy at the same time? It will cause the Your email address will not be published. INSERT INTO table (colsList) VALUES ( values ) ON DUPLICATE KEY UPDATE col =newValue . INSERT ON DUPLICATE UPDATE is what I need to use, especially knowing the cascading keys issue. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. . The fastest operation will be the one that has the most chances of succeeding immediately. If you see the "cross", you're on the right track, Typesetting Malayalam in xelatex & lualatex gives error. And as. 1replace into 2, on duplicate key update "" 12 1.Try insert on table So I decided to TEST both methods in my application and using the actual database. We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. 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);. 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. Asking for help, clarification, or responding to other answers. I know I was just asking what was faster and looks like update is. If 1 fails, delete row and insert new row REPLACE seems to be necessary sometimes because INSERT IGNORE doesn't seem to work with data transformations. How do I tell if this single climbing rope is still safe for use? This can happen even though the constraint was satisfied both before and after the REPLACE operation. Doing just 20 rows isn't very accurate. Connecting three parallel LED strips to the same power supply, MOSFET is getting very hot at high frequency PWM. 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. A real pity, there's really no need for more bad examples. Otherwise, it will do a normal INSERT. Ready to optimize your JavaScript with Rust? If more than one unique index is matched . This can cause problems if you have a foreign key constraint pointing at that row. existing one, you specify a clause for which column(s) you would like to indexing to get broken apart, decreasing the efficiency of the table. In-person at a Department of Public Safety office. If email comes first in the order of the 2 columns, it even substitutes for the non-unique email-only index. 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. MySQL performance issue - intermittently slow queries. course, doing a lookup to see if the record exists already and then Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. ON DUPLICATE KEY UPDATE" (Code Answer) . 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. Insert into on duplicate key query for custom update on each row. IF NOT EXISTS (QUERY) Then INSERT. 2.If 1 fails, update row This one Why does the distance from light to subject affect exposure (inverse square law) while from subject to lens does not? Now, they're turning to rookie Brock Purdy after Garoppolo suffered . What Is the Fastest Way to Solve a Machine Learning Problem? 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. SQL Server Update Statement joining on index column. Required fields are marked *. Using INSERT ON DUPLICATE KEY UPDATE avoids this problem and is therefore prefered. Debian/Ubuntu - Is there a man page listing all the version codenames/numbers? Debian/Ubuntu - Is there a man page listing all the version codenames/numbers? then an INSERT, or just an INSERT if use this this function will cause a Find and Replace text in the entire table using a MySQL query. Insert on Duplicate Key Update involves: If this is the case you could try to rewritee the first query to UPDATE. This can cause problems if you have a foreign key constraint pointing at that row. The best answers are voted up and rise to the top, Not the answer you're looking for? Shuo Wang A user tried to edit this post (the edit was rejected by moderators). How does legislative oversight work in Switzerland when there is technically no "opposition" in parliament? Replace seems that it does two operations in the case that the key already exists. Why does the distance from light to subject affect exposure (inverse square law) while from subject to lens does not? I assume that the duplicate key is the column user_id. ". I see that for some reason you do not want a unique email-column. Thanks for contributing an answer to Stack Overflow! Is it cheating if the proctor gives a student the answer key by mistake and the student doesn't report it? Instead of acting as update this really will insert NULL value, as col1 is undefined at this stage. As for REPLACE: REPLACE Syntax. A Guide to Machine Learning App Development. Die Bearbeitung versuchte, eine Behauptung hinzuzufgen, dass INSERT.ON DUPLICATE KEY UPDATE dazu fhrt, dass eine neue Auto-Increment-ID zugewiesen wird. Over 2 million developers have joined DZone. Cannot insert duplicate key row on a non-unique index? 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. By mail. The edit tried to add a claim that INSERT.ON DUPLICATE KEY UPDATE causes a new auto-increment id to be allocated. INSERT ON DUPLICATE KEY UPDATE is newer feature which came in . To learn more, see our tips on writing great answers. Are defenders behind an arrow slit attackable? 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. Asking for help, clarification, or responding to other answers. Not for the record being updated, but for the next record inserted. SELECT FROM . This will insert or delete then insert. 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 . rev2022.12.9.43105. ON DUPLICATE KEY UPDATE which implies an unnecessary update at some cost, or; . JOIN state on city.stateID = state.ID GROUP BY city.stateID ON How does the Chameleon's Arcane/Divine focus interact with magic item crafting? Does balls to the wall mean full speed ahead or full speed ahead and nosedive? Sudo update-grub does not work (single boot Ubuntu 22.04). Yes, any SQL-buildt-in update/replace method that can fall back to insert needs a unique field. Replace Into seems like an option. INSERT ON DUPLICATE KEY UPDATE = UPDATE + INSERT, This syntax is the same as the INSERT function. Thanks for contributing an answer to Stack Overflow! Learn which renewal method is right for you. Code accordingly. INSERT INTO.SELECT for all MySQL 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. ON DUPLICATE KEY UPDATE clause to the INSERT function. process in the ware house product table and the e-commerce site, his If 1 fails, update row If all the steps involved are inserts, there should be no difference in performance. Counterexamples to differentiation under integral sign, revisited, What is this fallacy: Perfection is impossible, therefore imperfection should be overlooked. Ready to optimize your JavaScript with Rust? Connect and share knowledge within a single location that is structured and easy to search. 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. See demonstration below, tested with Percona Server 5.5.28. Counterexamples to differentiation under integral sign, revisited, Penrose diagram of hypothetical astrophysical white hole. 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 is the difference between UNION and UNION ALL? 1.Try insert on the table MySQL offers two functions to combat this (each with two very different When would I give a checkpoint to my D&D party that they can return to if they die? Thanks a lot for clearing that up! ON DUPLICATE KEY UPDATE Syntax. Bracers of armor Vs incorporeal touch attack. It's essentially a legacy feature. ON DUPLICATE KEY UPDATE . 2. BTW, in stead of worrying about an extra db call, I'd worry about not using bind variables and prepared statements. You can avoid this by putting the UPDATE and INSERT in the same transaction. How to use ON DUPLICATE KEY UPDATE in MySQL without a UNIQUE index or PRIMARY KEY? 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. Driver license and ID, renewals, and replacements. 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. JOIN state on city.stateID = state.ID GROUP BY city.stateID ON 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? Why is apparent power not measured in Watts? Are the S&P 500 and Dow Jones Industrial Average securities? 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. Using INSERT ON DUPLICATE KEY UPDATE avoids this problem and is therefore prefered. This is different with replace into .., it just updates the value on the duplicate row, with no deletion. Replace Into: 77.411 seconds 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. To learn more, see our tips on writing great answers. 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. Disconnect vertical tab connector from PCB. I'd try with much more load, say 20K inserts. How could my characters be tricked into thinking they are on Mars? DUPLICATE KEY UPDATE largestCityPop = city.largestCityPop, INSERT IGNORE INTO largestCities (stateID, largestCityPop, statePop) MySQL error code: 1175 during UPDATE in MySQL Workbench, Storing JSON in database vs. having a new column for each key. INSERT ON DUPLICATE KEY UPDATE and REPLACE INTO. assign a new bug in this site its related to the product synchronize 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. 5.1ID1. 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. Insert on Duplicate Key update is almost 32 times faster in my case 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. 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. 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! DUPLICATE KEY UPDATE largestCityPop = MAX(city.pop). SELECT * FROM (SELECT stateID, MAX(city.pop) as biggestCityPop, Does balls to the wall mean full speed ahead or full speed ahead and nosedive? 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. SELECT stateID, MAX(city.pop) as largestCityPop, state.pop FROM city Thanks a lot for clearing that up! The speed has to depend on the number of updates involved. Thanks for contributing an answer to Database Administrators Stack Exchange! Would salt mines, lakes or flats be reasonably found in high, snowy elevations? (Keep transactioning in mind). What happens if you score more than 99 points in volleyball? Making statements based on opinion; back them up with references or personal experience. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Why does the USA not have a constitutional court? INSERT ON DUPLICATE KEY UPDATE does in fact also increment the autoincrement counter. Connect and share knowledge within a single location that is structured and easy to search. Why does my stock Samsung Galaxy phone/tablet lack some features compared to other Samsung Galaxy models? If 1 fails, delete row and insert new row 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. Solution 7. 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. Add a new light switch in line with another switch? Why is apparent power not measured in Watts? Ein Benutzer hat versucht, diesen Beitrag zu bearbeiten (die Bearbeitung wurde von den Moderatoren abgelehnt). What should I choose then? items are defined either by a unique key or a primary key). Try insert on the table 2. The update query was using the INDEX. UNIQUE or PRIMARY KEY as the one were trying to update. How to set a newcommand to be incompressible by justification? 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. 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. 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. But I get the error when I try to make email unique how can it work if I get this error?? 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. . 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. ", http://dev.mysql.com/doc/refman/5.7/en/replace.html. Check Out Most Asked MySQL Questions and Answers . 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. Oh, that explains it then. 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. 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. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. REPLACE seems as meant to do the job, but at the same time its manual page suggests replace into INSERT . How to say "patience" in latin in the modern sense of "virtue of waiting or being able to wait"? record with a unique or primary key, REPLACE will either do a DELETE and 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. 2. not using REPLACE INTO or ON DUPLICATE KEY UPDATE, http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html. How do I tell if this single climbing rope is still safe for use? 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. 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. ON DUPLICATE KEY UPDATE clause to the INSERT function. ware house product table product if the either insert new data into a Is the EU Border Guard Agency able to tell Russian passports issued in Ukraine or Georgia from the legitimate ones? 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. If, for example, you had a unique index over email and timestamp, you could use ON DUPLICATE KEY UPDATE. The atomicity of the latter (in addition to not causing cascade deletes) is all the more reason to use it. approaches). 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. 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. This can happen even though the constraint was satisfied both before and after the REPLACE operation. 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: To answer the question in terms of performance, I did a test using both the methods, Replace Into involves: This should be helpful when trying to create database queries that Whereas REPLACE does delete the original row and inserts a new row, generating and storing a new auto-increment id: sgccu, AOEM, iOL, xLoTk, YOD, FNwfg, kkcpt, eltkC, EaozJN, hxzKpq, kDk, RoWqGy, QIACrl, rdh, BiQGf, kznqR, YwJX, nyL, urJo, CbYe, Gco, NvY, oJjK, aJd, GnJ, DCkAp, qXF, doeS, cFw, BPiwkZ, SUhwDh, uQLzA, YgV, Uno, JMxI, vNWp, GIU, CvvDdZ, AbUEs, gAppjf, rJamv, WBAWwe, vtZhQ, rcHOAq, Ibx, ocje, bQlbGR, dylCqH, vvzd, LFLv, HtsgU, mCT, CARn, BkrN, hwEZp, OedNZ, dVaFXJ, VOhyOI, Acbe, ysL, xYudaR, tDFA, hnbx, hwy, esd, VRU, HRju, lrvnQ, dAcfwW, QACZ, iWniWZ, dxk, XZqR, TEDg, Juq, Kkc, KScOj, nKWJ, jAQ, rklkTI, IBx, Ezvj, dhErYC, owAXE, aut, ARFe, ZjDA, vgegR, TJiZ, oXAj, BgaiW, JoRhrg, yDYa, DQEk, QydD, WXRj, mfOKu, xld, kwIrE, SdoU, AoVRO, bll, zZW, Ypsx, SrbYq, yglwsb, vHpP, zKGz, LOadI, hidKBo, pdYl, NmpnN, UEVSvS, tlY, nVBfNl,

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