创建一个具有所需列名的新列:COLNew。

ALTER TABLE {tableName} ADD COLUMN COLNew {type};

将旧列COLOld的内容复制到新列COLNew。

INSERT INTO {tableName} (COLNew) SELECT {COLOld} FROM {tableName}

注:以上一行必须使用括号。

来自官方文件

对于某些不以任何方式影响磁盘上内容的更改，可以选择使用更简单、更快的过程。以下更简单的过程适用于删除CHECK或FOREIGN KEY或NOT NULL约束，重命名列，或添加、删除或更改列上的默认值。

Start a transaction. Run PRAGMA schema_version to determine the current schema version number. This number will be needed for step 6 below. Activate schema editing using PRAGMA writable_schema=ON. Run an UPDATE statement to change the definition of table X in the sqlite_master table: UPDATE sqlite_master SET sql=... WHERE type='table' AND name='X'; Caution: Making a change to the sqlite_master table like this will render the database corrupt and unreadable if the change contains a syntax error. It is suggested that careful testing of the UPDATE statement be done on a separate blank database prior to using it on a database containing important data. If the change to table X also affects other tables or indexes or triggers are views within schema, then run UPDATE statements to modify those other tables indexes and views too. For example, if the name of a column changes, all FOREIGN KEY constraints, triggers, indexes, and views that refer to that column must be modified. Caution: Once again, making changes to the sqlite_master table like this will render the database corrupt and unreadable if the change contains an error. Carefully test of this entire procedure on a separate test database prior to using it on a database containing important data and/or make backup copies of important databases prior to running this procedure. Increment the schema version number using PRAGMA schema_version=X where X is one more than the old schema version number found in step 2 above. Disable schema editing using PRAGMA writable_schema=OFF. (Optional) Run PRAGMA integrity_check to verify that the schema changes did not damage the database. Commit the transaction started on step 1 above.

一种选择是，如果你需要在紧要时刻完成它，如果你的初始列是用默认创建的，那就创建你想要的新列，将内容复制到它，然后基本上“放弃”旧列(它仍然存在，但你只是不使用/更新它，等等)。

ex:

alter table TABLE_NAME ADD COLUMN new_column_name TYPE NOT NULL DEFAULT '';
update TABLE_NAME set new_column_name = old_column_name;
update TABLE_NAME set old_column_name = ''; -- abandon old column, basically

这将留下一个列(如果它是用NOT NULL创建的，但没有默认值，那么未来的插入可能会忽略它)，但如果它只是一个丢弃的表，那么折衷可能是可以接受的。否则，请使用这里提到的其他答案之一，或者使用允许重命名列的不同数据库。

最近我不得不在SQLite3中使用一个名为points的表，列为id lon lat。错误地，当导入表时，latitude的值存储在lon列中，反之亦然，因此一个明显的修复方法是重命名这些列。所以窍门是:

create table points_tmp as select id, lon as lat, lat as lon from points;
drop table points;
alter table points_tmp rename to points;

我希望这对你有用!

虽然确实没有ALTER COLUMN，但如果您只想重命名列、删除NOT NULL约束或更改数据类型，则可以使用以下命令集:

注意:这些命令有可能破坏数据库，因此请确保您有备份

PRAGMA writable_schema = 1;
UPDATE SQLITE_MASTER SET SQL = 'CREATE TABLE BOOKS ( title TEXT NOT NULL, publication_date TEXT)' WHERE NAME = 'BOOKS';
PRAGMA writable_schema = 0;

您将需要关闭并重新打开连接，或者清空数据库以将更改重新加载到模式中。

例如:

Y:\> sqlite3 booktest  
SQLite version 3.7.4  
Enter ".help" for instructions  
Enter SQL statements terminated with a ";"  
sqlite> create table BOOKS ( title TEXT NOT NULL, publication_date TEXT NOT NULL);  
sqlite> insert into BOOKS VALUES ("NULLTEST",null);  
Error: BOOKS.publication_date may not be NULL  
sqlite> PRAGMA writable_schema = 1; 
sqlite> UPDATE SQLITE_MASTER SET SQL = 'CREATE TABLE BOOKS ( title TEXT NOT NULL, publication_date TEXT)' WHERE NAME = 'BOOKS';  
sqlite> PRAGMA writable_schema = 0;  
sqlite> .q  

Y:\> sqlite3 booktest  
SQLite version 3.7.4  
Enter ".help" for instructions  
Enter SQL statements terminated with a ";"  
sqlite> insert into BOOKS VALUES ("NULLTEST",null);  
sqlite> .q  

引用: 编译指示writable_schema 当打开此pragma时，数据库所在的SQLITE_MASTER表可以使用普通的UPDATE、INSERT和DELETE语句进行更改。警告:误用此pragma很容易导致数据库文件损坏。

alter table SQLite支持ALTER TABLE的一个有限子集。SQLite中的ALTER TABLE命令允许用户重命名表或向现有表添加新列。不能重命名列、删除列或从表中添加或删除约束。

需要重命名一些表中的一些列

另一种方法是使用多个SQLite3命令来“重命名”列， 在“一些”表中，根据需要重复:

.output tmp

SELECT "ALTER TABLE """|| sqlite_master.name ||""" RENAME COLUMN old_name TO new_name;" FROM sqlite_master 
WHERE type = "table" AND sqlite_master.name NOT LIKE 'sqlite_%';

.read tmp

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