步骤一:了解ALTER TABLE语句 在开始之前,我们先来了解一下ALTER TABLE语句的语法。ALTERTABLE语句用于修改已存在的表结构。它的基本语法如下: ALTER TABLE table_name ADD COLUMN column_name_1 data_type [constraint], ADD COLUMN column_name_2 data_type [constraint], ... ADD COLUMN column_name_n data_...
1. 菜鸟教程 2. sqlite alter table add MULTIPLE columns in a single statemen there 3. sqlite官网——Alter Table
ADD COLUMN语句。SQLite 3.1.3(2005-02-20)增加了对格式2的读写支持。 格式3:增加了对ALTER TABLE…ADD COLUMN语句非空缺省值的支持,从SQLite 3.1.4(2005-03-11)开始支持格式3。 格式4:增加了index声明时对DESC关键字的支持(之前的版本1,2,3都忽略了DESC关键字),此外格式4还增加了对2种boolean记录类型的...
CREATE TABLE test1(a,b); As you can see, the SQLite CREATE TABLE syntax is pretty forgiving, and you don't even have to specify the data types of the table columns. This means that you can also add a new column without specifying its type, like this: ALTER TABLE test1 ADD COLUMN ...
ALLOW_PAGE_LOCKS = ON ) ON ) ON -- 添加维一约束 ALTER TABLE TableDescription ADD CONSTRAINT un_TableDescription_TableName UNIQUE (TableName ) /*** 对象 : Table [dbo].[FieldDescription] ***/ CREATE TABLE [dbo] .[FieldDescription] ( IDENTITY (1 ,1 ) NOT FOR REPLICATION NOT NULL, ...
upgradeTables([userDAO.table]);NOTE: autoupgrade should be carefully tested before running it on a production database! A backup should be self-evident!NOTE: renaming of columns can not be detected! autoupgrade would normally add a new column with the new name and the data in the old ...
The SQLiteALTER TABLEdocumentation can be foundhere. If youadd new columnsyou can use ALTER TABLE to insert them into a live table. If yourename or remove columnsyou can use ALTER TABLE to rename the old table, then create the new table and then populate 填充 the new table with the cont...
• Multiple cells/rows/columns selection. • View table data with a convenient filter. • Sort records by tapping on column title. • Edit blob data as hex or show it as preview if possible. Alter Table • View, edit or add table fields, indexes, foreign keys, checks. ...
column += columns[i]+","; } column=column.substring(0, column.length()-1); sql = "INSERT INTO " + from + " (" + column + ") " + " SELECT " + column + " FROM " + to; //4、删除修改之前的数据表 db.execSQL("DROP TABLE IF EXISTS " + to); ...
$table string The table that the foreign key constraint will be added to. $columns string|array The name of the column to that the constraint will be added on. If there are multiple columns, separate them with commas or use an array to represent them. $refTable string The table that the...