ALTERTABLE表名 CHANGECOLUMN列名 数据类型,CHANGECOLUMN列名 数据类型 删除单列: ALTERTABLE表名DROPCOLUMN列名 删除多列: ALTERTABLE表名DROPCOLUMN列名1,DROPCOLUMN列名2 同时添加和修改多列: ALTERTABLE表名ADD列名1 数据类型1,CHANGECOLUMN列名 数据类型,DROPCOLUMN列名1--COLUMN关键字可以省略 --- SqlServer(Transa...
1.增加字段 alter table docdsp add dspcode char(200) 2.删除字段 alter table table_name drop column column_name 3.修改字段类型 alter table table_name alter column column_name new_data_type 2.6.1. 增加字段 要增加一个字段,使用这条命令: alter table products add column description text; 新增的...
Adding a string (varchar) column with a not null constraint: -- note: this is possible only if the table contains no data!! alter table products add description varchar(100) not null; Adding more columns at the same time: alter table products add brand_id smallint default 1, description...
Column Name Data Type Length Precision Scale Allow Nulls Default Value Identity Identity Seed Identity Increment Row GUID Nullable Condensed Type Not for Replication Formula Collation Description 最终效果图如下: 注册表设置值是:1,2,6,17,7; 计算机\HKEY_CURRENT_USER\Software\Microsoft\SQL Server Manageme...
表名add constraint 约束名字 DEFAULT 默认值 for 字段名称 ---说明:添加一个表的字段的约束并指定默认值 --修改字段名: alter table 表名rename column A to B --修改字段类型: alter table 表名alter column UnitPrice decimal(18, 4) not null --增加字段: alter table 表名ADD 字段 类型 NOT NULL D...
CREATE TABLE t_account ( accountkey int NOT NULL PRIMARY KEY NONCLUSTERED, Accountdescription nvarchar (50), accounttype nvarchar(50), unitsold int, INDEX t_account_cci CLUSTERED COLUMNSTORE ) WITH (MEMORY_OPTIMIZED = ON ); 现在,无需对应用程序进行任...
-- 层级顺序保持从高到低 --> <global sum-label="总计" label-column="fruit_name" /> <!-- order-column: 分组排序列(对同分组进行排序),order-with-sum:默认为true,order-way:desc/asc --> <group group-column="fruit_name" sum-label="小计" label-column="fruit_name" /> </sql> 效果...
Create a nonclustered index on a columnstore table.--Create the tableCREATETABLEt_account ( AccountKeyintNOTNULL, AccountDescriptionnvarchar(50), AccountTypenvarchar(50), UnitSoldint);--Store the table as a columnstore.CREATECLUSTERED COLUMNSTOREINDEXtaccount_cciONt_account;--Add a nonclustered index...
NOTICE: Replica identity is neededforshard table, pleaseaddto this table through"alter table"command. CREATE TABLE postgres=# 查看表结构 postgres=# \d+ t_native_range Table"tdsql_pg.t_native_range" Column|Type|Collation|Nullable|Default|Storage|Stats target|Description ...
add_column_options::= Text description of add_column_options (constraints: constraint_clause, alter_column_properties::=) modify_column_options::= Text description of modify_column_options (column_constraint: constraint_clause, LOB_storage_clause::=) drop_column_clause::= ...