Updating primary key
This is a very specific case where relationship() must perform an INSERT and a second UPDATE in order to properly populate a row (and vice versa an UPDATE and DELETE in order to delete without violating foreign key constraints).The two use cases are: In the first case, a row points to itself.
This specifies that the linkage between the two rows should be created using an UPDATE statement after both rows have been INSERTED; it also causes the rows to be de-associated with each other via UPDATE before a DELETE is emitted.CREATE TABLE mytable (a int, b int, s int static, d text, PRIMARY KEY (a, b)) BEGIN BATCH INSERT INTO mytable (a, b, d) values (7, 7, 'a') UPDATE mytable SET s = 7 WHERE a = 7 IF s = NULL; APPLY BATCH conditional succeeds, so the batch succeeds.We had a requirement to develop a functionality such that Whenever orders are manually entered, and the customer material is required to appear on the sales order, CMIR and MD (when working together) does not always retrieve the customer material properly.If your code updates all map collections this way, it generates many tombstones, which may slow the system down.The examples above use map collections, but the same caution applies to updating sets.Foreign key constraints are an integral part of SQL Server database design.
These are used to maintain integrity among related data in different tables.
Technically, a database that uses sequences such as Postgre SQL or Oracle can INSERT the row at once using a previously generated value, but databases which rely upon autoincrement-style primary key identifiers cannot. In the second case, the “widget” row must be inserted before any referring “entry” rows, but then the “favorite_entry_id” column of that “widget” row cannot be set until the “entry” rows have been generated.
In this case, it’s typically impossible to insert the “widget” and “entry” rows using just two INSERT statements; an UPDATE must be performed in order to keep foreign key constraints fulfilled.
In addition, you can delete a column's TTL by setting its Update a row in a table with a complex primary key: To do this, specify all keys in a table having compound and clustering columns.
For example, update the value of a column in a table having a compound primary key, userid and url: UPDATE excelsior.clicks USING TTL 432000 SET user_name = 'bob' WHERE userid=cfd66ccc-d857-4e90-b1e5-df98a3d40cd6 AND url=' UPDATE Movies SET col1 = val1, col2 = val2 WHERE movie ID = key1; UPDATE Movies SET col3 = val3 WHERE movie ID IN (key1, key2, key3); UPDATE Movies SET col4 = 22 WHERE movie ID = key4; These two statements seem to do the same thing.
Darren In general it is not possible to run a delete/insert on the parent table, either the delete rule is restrict, then it is not allowed if dependent rows exist or the delete rule is cascade, which will delete all dependent rows.