Sql updating primary key value

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We could also create a primary key with more than one field as in the example below: In this example, we've created a primary key on the existing supplier table called supplier_pk. A primary key is a field or set of fields with values that are unique throughout a table.None of the fields that are part of the primary key can contain a null value. In this example, we've created a primary key on the supplier table called supplier_pk.It consists of only one field - the supplier_id field.TABLES WHERE TABLE_NAME='ins_duplicate'; ---------------- | Auto_increment | ---------------- | 5 | ---------------- INSERT INTO ins_duplicate VALUES (2,'Leopard') ON DUPLICATE KEY UPDATE animal='Leopard'; Query OK, 2 rows affected (0.00 sec) SELECT Auto_increment FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME='ins_duplicate'; ---------------- | Auto_increment | ---------------- | 5 | ---------------- INSERT INTO ins_duplicate VALUES (5,'Wild Dog') ON DUPLICATE KEY UPDATE animal='Wild Dog'; Query OK, 1 row affected (0.09 sec) SELECT * FROM ins_duplicate; ---- ---------- | id | animal | ---- ---------- | 1 | Antelope | | 2 | Leopard | | 3 | Zebra | | 4 | Gorilla | | 5 | Wild Dog | ---- ---------- SELECT Auto_increment FROM INFORMATION_SCHEMA.

That's why many DBs will stop you changing the PK column values. That's why many DBs will stop you changing the PK column values.The flag should be placed on just When a structure against the above configuration is flushed, the “widget” row will be INSERTed minus the “favorite_entry_id” value, then all the “entry” rows will be INSERTed referencing the parent “widget” row, and then an UPDATE statement will populate the “favorite_entry_id” column of the “widget” table (it’s one row at a time for the time being): BEGIN (implicit) INSERT INTO widget (favorite_entry_id, name) VALUES (? ) (None, 'somewidget') INSERT INTO entry (widget_id, name) VALUES (? ) (1, 'someentry') UPDATE widget SET favorite_entry_id=? (1, 1) COMMIT When the primary key of an entity changes, related items which reference the primary key must also be updated as well.For databases which enforce referential integrity, the best strategy is to use the database’s ON UPDATE CASCADE functionality in order to propagate primary key changes to referenced foreign keys - the values cannot be out of sync for any moment unless the constraints are marked as “deferrable”, that is, not enforced until the transaction completes.Now I can view fields, insert fields and delete fields.Can't update And for the record, if I re-generate the default class that has those pesky PK lines then my gui/view class doesn't work at all.

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