SQLite使用dropcolumn删除表字段如下sql语句会复制一个和record表一样表结构的temp表出来但是我们想要的是去除某一个字段例如去除record表中的name字段就不要复制它就好了所以sql语句如下 SQLite 使用 dropcolumn 删除表字段 由于项目需求变更,我需要在 sqlite 数据库的表中删除一个字段, 通用的 sql 操作语句如下: [...
how to drop a column in sqlite 在sqlite中可以使用ALTER TABLE语法对表结构进行修改,从官方的文档说明中,语法如下图: 从图中可以看出,ALTER TABLE仅仅支持表名重命名,添加字段,却没有删除字段的方法。那么该如何实现,当然了首先search 一下,群众们给出的一个解决方案就是将数据备份到一张临时表,删除原始表,然...
SQLite使用drop column删除表字段 由于项目需求变更,我需要在sqlite数据库的表中删除一个字段,通用的sql操作语句如下: [sql] view plain copy alter table record drop column name; 结果数据库提示如下错误: 搜索得知,原来SQLite目前还不支持drop column,所以必须想出另外一种方法来进行表字段的删除。 如下sql语句会...
由于项目需求变更,我需要在sqlite数据库的表中删除一个字段,通用的sql操作语句如下: altertablerecorddropcolumnname; 1. 结果数据库提示如下错误: 搜索得知,原来SQLite目前还不支持drop column,所以必须想出另外一种方法来进行表字段的删除,读者要是说:“直接删掉这个表,然后在新建不见行了!”。 好吧,既然你这么不...
lijinma 吹牛大王 @ 币圈金马奖
Hi, SQLite doesn't support modifying constraints/columns to an existing table so DBeaver allows to set them only during table creation so I suggest to support modifying constraints/columns by using this trick (I hate to write scripts whe...
ALTER TABLE ADD COLUMN IF NOT EXISTS column_name CREATE INDEX IF NOT EXISTS index_name I do not think it is like RECREATE. I do not want to create it again or modify existing table data. That is not what Adriano said. He just said the RECREATE and CREATE OR ALTER statements are also...
Solution: -- Remove the index 'idx_customer' from the Orders table.ALTERTABLEOrdersDROPINDEXidx_customer; Copy Explanation: Purpose of the Query: To eliminate an index that is redundant or no longer improves query performance. Helps in reducing storage overhead and maintenance cost....
Im creating a shopping application which stores the users selected cart items in an sqlite table, Im wanting to delete that table everytime the application is openned, not restored.Ive looked at the drop table, but everything I try in their kicks out with an error telling me the table ...
adding the checkbox column in to WPF datagrid and select the checked rows ?? Adding user control that has no default constrctor in mainwindow throws exception. Adding UserControl programmatically Adjust the height of the WPF window Automatically based on window size ! Advice on a help file for...