Your assumption is right, this is the optimal way to do it and it’s called upsert/merge. Importance of UPSERT – from sqlservercentral.com: For every update in the case mentioned above we are removing one additional read from the table if we use the UPSERT instead of EXISTS. Unfortunately for an Insert, both the UPSERT and … Read more
Update, July 2022: You can save some typing by using this function to build the MERGE statement and perform the upsert for you. SQL Server offers the MERGE statement: import pandas as pd import sqlalchemy as sa connection_string = ( “Driver=ODBC Driver 17 for SQL Server;” “Server=192.168.0.199;” “UID=scott;PWD=tiger^5HHH;” “Database=test;” “UseFMTONLY=Yes;” ) connection_url = sa.engine.URL.create( “mssql+pyodbc”, … Read more
Update: You can save yourself some typing by using this method. If you are using PostgreSQL 9.5 or later you can perform the UPSERT using a temporary table and an INSERT … ON CONFLICT statement: import sqlalchemy as sa # … with engine.begin() as conn: # step 0.0 – create test environment conn.exec_driver_sql(“DROP TABLE IF … Read more
Modern releases of pymongo ( greater than 3.x ) wrap bulk operations in a consistent interface that downgrades where the server release does not support bulk operations. This is now consistent in MongoDB officially supported drivers. So the preferred method for coding is to use bulk_write() instead, where you use an UpdateOne other other appropriate … Read more
UPDATE will not do anything if the row does not exist. Where as the INSERT OR REPLACE would insert if the row does not exist, or replace the values if it does.
I believe xmax::text::int > 0 would be the easiest trick: so=# DROP TABLE IF EXISTS tab; NOTICE: table “tab” does not exist, skipping DROP TABLE so=# CREATE TABLE tab(id INT PRIMARY KEY, col text); CREATE TABLE so=# INSERT INTO tab(id, col) VALUES (1,’a’), (2, ‘b’); INSERT 0 2 so=# INSERT INTO tab(id, col) VALUES (3, … Read more
i finally got the Upsert syntax using MERGE in SQL Server 2008. Using what Jacob wanted to do (an Upsert): IF EXISTS(SELECT * FROM member_topic WHERE mt_member = 0 AND mt_topic = 110) BEGIN –update existing row UPDATE member_topic SET mt_notes=”test” WHERE mt_member = 0 AND mt_topic = 110 END ELSE BEGIN –insert new row … Read more
Field should appear either in $set, or in $setOnInsert. Not in both.
The reason this feels weird to you is that you are thinking of the increment on the counter as part of the insert operation, and therefore the “DO NOTHING” ought to mean “don’t increment anything”. You’re picturing this: Check values to insert against constraint If duplicate detected, abort Increment sequence Insert data But in fact, … Read more
Yes, DB2 has the MERGE statement, which will do an UPSERT (update or insert). MERGE INTO target_table USING source_table ON match-condition {WHEN [NOT] MATCHED THEN [UPDATE SET …|DELETE|INSERT VALUES ….|SIGNAL …]} [ELSE IGNORE] See: http://publib.boulder.ibm.com/infocenter/db2luw/v9/index.jsp?topic=/com.ibm.db2.udb.admin.doc/doc/r0010873.htm https://www.ibm.com/support/knowledgecenter/en/SS6NHC/com.ibm.swg.im.dashdb.sql.ref.doc/doc/r0010873.html https://www.ibm.com/developerworks/community/blogs/SQLTips4DB2LUW/entry/merge?lang=en