If your run this test code you will see that the value for the field seq is equal to the maximum value inserted in the PRIMARY KEY field.Īfter this if you try to insert a new record in your table you will see that the AUTOINCREMENT flag has started to work as expected and your new record will receive the next value from the sequence.
Int lastInsertedValue = Convert.ToInt32(cmd.ExecuteScalar()) The keyword SQLite AUTOINCREMENT is used when creating a table in the database, it is assigned to a column to automatically increase the respective column with. This table could be read by the usual ADO.NET classes cmd.CommandText = "SELECT seq FROM sqlite_sequence WHERE name = 'tblName'" Now, when you create a table with the AUTOINCREMENT SQLite add a new row to an internal table called sqlite_sequence. So your code to add the AUTOINCREMENT flag to your table is something like this SQLiteCommand cmd = new SQLiteCommand() Ĭmd.CommandText = "ALTER TABLE tblName RENAME TO tmp_tblName" ĪnotherField NVARCHAR(100) NOT NULL)", cnn) Ĭmd.CommandText = "INSERT INTO tblName (ID, AnotherField) SELECT ID, AnotherField FROM tmp_tblName"
It can be applied to a field when creating a table. SQLite Database Analyzer (sqlite3analyzer.exe) This stand-alone program reads an SQLite database and outputs a file showing the space used by each table and index and.
The AUTOINCREMENT keyword can be used with INTEGER PRIMARY KEY field only. Command-Line Shell (sqlite3.exe) Notes on using the 'sqlite3.exe' command-line interface that can be used to create, modify, and query arbitrary SQLite database files. You are forced to rename your original table, create a new table with the schema you want and then copy from the renamed table into the new one. The SQLite AUTOINCREMENT is a keyword used for auto incrementing a value of a field in the table. The below mentioned statement creates a table called Employee which contains five columns: EmpID, Name, City, Age and Salary in which auto-increment is applied on column EmpID.The first thing to say here is that SQLite has no syntax to change the settings of a column. In other words, the purpose of AUTOINCREMENT is to prevent the reuse of ROWIDs from previously deleted rows. Essentially, I want ID to auto increment whenever I. If the AUTOINCREMENT keyword appears after INTEGER PRIMARY KEY, that changes the automatic ROWID assignment algorithm to prevent the reuse of ROWIDs over the lifetime of the database. create table items ( id integer autoincrement, version integer default 0, primary key (id, version) ). This is true regardless of whether or not the AUTOINCREMENT keyword is used. On an INSERT, if the ROWID or INTEGER PRIMARY KEY column is not explicitly given a value, then it will be filled automatically with an unused integer, usually one more than the largest ROWID currently in use. In SQLite, a column with type INTEGER PRIMARY KEY is an alias for the ROWID (except in WITHOUT ROWID tables) which is always a 64-bit signed integer. The AUTOINCREMENT keyword imposes extra CPU, memory, disk space, and disk I/O overhead and should be avoided if not strictly needed. The AUTOINCREMENT keyword can be used with INTEGER PRIMARY KEY field only. The SQLite AUTOINCREMENT is a keyword used for auto incrementing a value of a field in the table.
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