-
@H_301_3@ SQLite不支持对列的改名和修改类型等操作，想要操作官方给出的方法是先备份原表数据到临时表，然后删除原表，再创建新的表结构，然后导入临时表的数据，官方解释如下：(11) How do I add or delete columns from an existing table inSQLite.
@H_301_3@ 推荐几个学习sqlite有用的官方链接：SQLite has limitedALTER TABLEsupport that you can use to add a column to the end of a table or to change the name of a table. If you want to make more complex changes in the structure of a table,you will have to recreate the table. You can save existing data to a temporary table,drop the old table,create the new table,then copy the data back in from the temporary table.
For example,suppose you have a table named “t1″ with columns names “a”,“b”,and “c” and that you want to delete column “c” from this table. The following steps illustrate how this could be done:
BEGIN TRANSACTION; CREATE TEMPORARY TABLE t1_backup(a,b); INSERT INTO t1_backup SELECT a,b FROM t1; DROP TABLE t1; CREATE TABLE t1(a,b); INSERT INTO t1 SELECT a,b FROM t1_backup; DROP TABLE t1_backup; COMMIT;
http://www.sqlite.org/Syntaxdiagrams.html#column-def
http://www.sqlite.org/faq.html#q11
