System.Data.Entity CreateDatabaseIfNotExists<TContext> 数据库 数据库 属性 方法 BeginTransaction CompatibleWithModel 创建 CreateIfNotExists 删除 等于 ExecuteSqlCommand ExecuteSqlCommandAsync Exists GetHashCode GetType Initialize SetInitializer SqlQuery
mysql> CREATE DATABASE userdb; Query OK, 1 row affected (0.00 sec) mysql> USE userdb; Database changed 新建userlist表,字段设置及相关操作参考如下: mysql> CREATE TABLE userlist( -> username varchar(24) NOT NULL, -> password varchar(48) DEFAULT 'x', -> uid int(5) NOT NULL, -> gid ...
To create the database, select OK. Use Transact-SQL Connect to the Database Engine. From the Standard bar, select New Query. Copy and paste the following example into the query window and select Execute. This example creates the database Sales. Because the keyword PRIMARY isn't used, the...
In Query Editor, press F5 to execute the statement and create a database named TestData. When you create a database, SQL Server makes a copy of the model database, and renames the copy to the database name. This operation should only take several seconds, unless you specify a large in...
Learn How to create and manage a database in SQL, this is the place to start! you will be rewarded with learning some very dry material,The classic SQL Query for iPad, iPhone and iPod touch. “SQL Query “is a perfect tool for studying, complex , daily use SQL Query in company ...
mysql>?CREATEDATABASEName:'CREATE DATABASE'Description: Syntax:CREATE{DATABASE|SCHEMA}[IF NOT EXISTS]db_name[create_specification]... create_specification:[DEFAULT]CHARACTERSET[=]charset_name|[DEFAULT]COLLATE[=]collation_nameCREATEDATABASEcreates adatabasewiththe given name.Tousethis ...
IF NOT EXISTS (SELECTnameFROMsys.databasesWHEREname= N'Library')CREATEDATABASELibrary; 如果尚未存在,此腳本會建立名為Library的新資料庫。 新的Library資料庫會出現在資料庫清單中。 If you don't see it immediately, refresh the Object Explorer. ...
Lesson 1: Create & query database objects Lesson 2: Configure permissions on database objects Lesson 3: Delete database objects SQL Server on Linux SQL on Azure Azure Arc Resources Reference Læs på engelsk Tilføj Føj til samlinger ...
使用create database创建数据库: mysql>createdatabase test; ##创建数据库成功 Query OK,1rowaffected (0.08sec) mysql>createdatabase test; ##再次创建数据库失败 ERROR1007(HY000): Can't create database 'test'; database exists mysql> create database if not exists test; ##语句执行成功 ...
数据操作语言(Data Manipulation Language,DML) 用来变更表中的记录,主要包含以下几种命令: SELECT:查询表中的数据 INSERT:向表中插入新数据 UPDATE:更新表中的数据 DELETE:删除表中的数据 数据查询语言(Data Query Language,DQL) 用来查询表中的记录,主要包含SELECT命令,来查询表中的数据。