Is it possible t开发者_开发技巧o reseed an auto increment column in a SQLite database, and if so, how is this done?
ie. The equivalent of DBCC CHECKIDENT ('MyTable', RESEED, 1)
in SQL Server.
In SQLite there is a table named SQLITE_SEQUENCE, which tracks the largest RowId
value that a table has. You can do insert, updates and deletes on this table. For example, to mimic similar functionality as the TRUNCATE TABLE statement SQL Server you could something like:
DELETE FROM MyTableName;
DELETE FROM SQLITE_SEQUENCE WHERE NAME = 'MyTableName';
In the above example all data from MyTableName is removed, and the auto increment rowid is reset by removing the value from the SQLITE_SEQUENCE table. See the documentation for AUTOINCREMENT for more information.
DELETE
FROM MyTableName
select *
from SQLITE_SEQUENCE
update SQLITE_SEQUENCE
set seq = 0
where name ='MyTableName'
Alternatively you could export a SQL file from the SQLite database. Then edit the generated SQL file and update the appropriate entries to the desired IDs or delete the INSERT statements. After this create a new empty database and seed it with the adjusted SQL file. The highest ID + 1 will then be the ID for a new entry...
With this way you can decide, which entries to keep and which entries should be removed as a non-destructive or even a more flexible approach.
For me it worked - clean and easy. ;)
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