You can use the INSERT INTO with ON DUPLICATE KEY UPDATE and VALUES() function to insert data in a database, or insert it, if a unique or primary key would be violated. It is a good idea to use a properly defined multi column unique index with this method. Posts about ON DUPLICATE KEY UPDATE written by lukaseder. Java, SQL and jOOQ.
Update the table first using update query and where clause b. If update fails then insert the record into table using insert query ON DUPLICATE KEY UPDATE will only update the columns you specify and preserves the row. From the manual : 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. In MySQL, if you specify ON DUPLICATE KEY UPDATE and a row is inserted that would cause a duplicate value in a UNIQUE index or PRIMARY KEY, an UPDATE of the old row is performed. For example, if column a is declared as UNIQUE and contains the value 1, the following two statements have identical effect: ON DUPLICATE KEY UPDATE statements just shown can be done as shown here: INSERT INTO t1 SET a=1,b=2,c=3 AS new ON DUPLICATE KEY UPDATE c = new.a+new.b; INSERT INTO t1 SET a=1,b=2,c=3 AS new(m,n,p) ON DUPLICATE KEY UPDATE c = m+n; The row alias must not be the same as the name of the table. If we update the existing row into a table, it returns two affected-rows. If we update the existing row using its current values into the table, it returns the number of affected-rows 0.
a. Update the table first using update query and where clause b. If update fails then insert the record into table using insert query ON DUPLICATE KEY UPDATE requires a unique key on the target table, and unique keys are only supported on rowstores. It’s a priority for us to make unique keys and ON DUPLICATE KEY UPDATE work on columnstores in the future.
言葉で説明しただけではイメージが掴みにくいと思うので、 実際にinsert … on duplicate key update構文を使ってみたい と思います。 on duplicate key update ステートメントの insert 部分からカラム値を参照できます。 つまり、ON DUPLICATE KEY UPDATE 句にある VALUES(col_name) は、重複キーの競合が発生していない場合に挿入される col_name の値を参照します。 Se hela listan på sql.sh 2018-10-31 · 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. So we got the new line (2,2,4) instead of (2,3,4).
Sometimes, when updating on duplicate key it comes in handy to use VALUES() in order to access the original value that was passed to the INSERT instead of setting the value directly. cyjake commented on Apr 15, 2016 •edited. let insert = knex(table).insert(data) delete data.id let update = knex(table).update(data) let query = util.format('%s on duplicate key update %s', insert.toString(), update.toString().replace(/^update ([`"])[^\1]+\1 set/i, '')) return knex.raw(query) Copy link. ON DUPLICATE KEY UPDATE statement. In other words, VALUES(col_name) in the ON DUPLICATE KEY UPDATE clause refers to the value of col_name that would be inserted, had no duplicate-key conflict occurred. ON DUPLICATE KEY UPDATE which implies an unnecessary update at some cost, or; INSERT IGNORE which implies an invitation for other kinds of failure to slip in unannounced.
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In my research, I discovered that this is specific to MySQL. In my case, this was still be a valuable requirement for my Web Application and was worth extending Yii to get working. Se hela listan på sql.sh inserton duplicate key update構文を使うと. レコードがなければinsert、あればupdate; 複数行の一括update; フィールド毎に条件判定して更新; を1度のクエリで行うことができる。集計処理などに便利。 基本 ON DUPLICATE KEY UPDATE" insert failure, caused by a duplicate key error, would result in duplicate auto-increment values." [6 Jun 2013 15:44] Laurynas Biveinis The commit message is missing the public bug db number, making it harder to find.
Best Practices and Lessons Learned from Writing Awesome Java and SQL Code. on duplicate key update单个增加更新及批量增加更新的sql 在MySQL数据库中，如果在insert语句后面带上ON DUPLICATE KEY UPDATE 子句，而要插入的行与 表中现有记录的惟一索引或主键 中产生重复值，那么就会发生旧行的更新；如果插入的行数据与现有 表中记录的唯一索引或者主键 不重复，则执行新纪录插入操作。
ON DUPLICATE KEY UPDATE inserts or updates a row, the LAST_INSERT_ID() function returns the AUTO_INCREMENT value. The problem is that in case of updating record LAST_INSERT_ID() from MySQL will
ON DUPLICATE KEY UPDATE clause to the INSERT function. This one actively hunts down an existing record in the table which has the same UNIQUE or PRIMARY KEY as the one we’re trying to update.
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From the manual: 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. 2017-11-09 NOTE#2: ON DUPLICATE KEY UPDATE makes update for existing PK ID record.
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; ON DUPLICATE KEY UPDATE does not extend to subqueries. E.g.: INSERT INTO t1 VALUES(1,2) ON DUPLICATE KEY UPDATE a=(SELECT a FROM t2 WHERE b=VALUES(b)); This does not do what the user expects. VALUES(b) will return NULL, even if it is in an INSERT .. ON DUPLICATE KEY UPDATE statement.
The ON DUPLICATE KEY UPDATE clause can contain multiple column assignments, separated by commas. In assignment value expressions in the ON DUPLICATE KEY UPDATE clause, you can use the VALUES (col_name) function to refer to column values from the INSERT portion of the INSERT ON DUPLICATE KEY UPDATE statement.