On 26 Dec 2012, at 1:36pm, genliu777 <doityth...@163.com> wrote: > as you sayed, knowing the ROWID means i can deal with the SQL query which > you mention to move back or move forwark through the table! but, i do not > get the ROWID really yet and further do not know how to get the ROWID by > any API funtion supplied by sqlite3!!!
rowid is a special column especially made by SQLite. Suppose you define a table like CREATE TABLE myTable (a INTEGER, b TEXT) even though you did not ask for a column called rowid, SQLite will create one anyway. It's a special secret column ! It will contain a numeric value which automatically increments for each new row: 1, 2, 3 ... If you ask for SELECT * FROM myTable you will not get a value for rowid, because it's a secret column. But if you explicitly ask for it: SELECT rowid FROM myTable SELECT b,rowid FROM myTable SELECT rowid,* FROM myTable then SQLite will return its value. Try it out ! SQLite has been making this column for every table you've made, unless you define a column called rowid yourself. So you can use this column on tables in old databases you already have. You don't need to start a new one. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
