![]() When I now have a foreign key constraint ON DELETE CASCADE on this primary key in another table, the entries in the other tables always get deleted. I want to copy all data from ItemsB into ItemsA. Insert_stmt = insert(my_table).values(list(data_iter))ĭo_nothing_stmt = insert_stmt. The problem is that my current attempts are always failing due to the fact, that SQLite always deletes the row first and inserts it with the new values and the same primary key. UPDATE or a no-op if the INSERT would violate a uniqueness constraint. You can do this with the method parameter of tosql: from import insert def insertonduplicate (table, conn, keys, dataiter): insertstmt insert (table.table).values (list (dataiter)) onduplicatekeystmt insertstmt.onduplicatekeyupdate (insertstmt.inserted) conn.execute (onduplicatekeystmt) df.to. My_table = table(sql_table.name, *columns) Also, this command will eventually burn out all your auto increment primary keys prematurely. in the above contrived example if I go from using 'three' for foo.name to 'two' it updates fine, but if I then run again with 'three' it does not update. ![]() On duplicate key update - the performance shot waaaaay up. INSERT INTO bar (key, fooID) SELECT 'key', foo.id FROM foo WHERE foo.name'three' ON CONFLICT (key) DO UPDATE SET fooIDexcluded.id But it only sometimes seems to update the existing row, eg. I had code using this for a while and when I migrated to Insert. ![]() The INSERT ON DUPLICATE KEY UPDATE is a MySQLs extension to the SQL standards INSERT. Table_name = ''.format(sql_table.schema, sql_table.name) The delete command takes resources, then you have to edit all the indexes, the unique ones taking the longest. Introduction to the MySQL INSERT ON DUPLICATE KEY UPDATE statement. def insert_do_nothing_on_conflicts(sqltable, conn, keys, data_iter):Ĭonn : or ĭata_iter : Iterable that iterates the values to be insertedįrom import insert The below code should work for postgres and do nothing if there's a conflict with primary key "unique_code". With SQLite you cannot do the simple MySQL INSERT on duplicate key UPDATE: INSERT INTO table (id, name, price, quantity) VALUES(1, test, 2. shall it be updated too, or only 'value') Also, on duplicate key requires, well, a key. There's a method parameter you can pass to panda.to_sql to help achieve customization for your sql query asked at 17:15 Thallius 2,482 2 18 36 In your sample result, is the 'lastupdate' '' or not (e.g. The for loop method above slow things down significantly.
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