Code: DROP TABLE [IF EXISTS] [db_name.][schema_name.]table_name; In the above syntax: Name the table that has to be deleted first. Second, mention both the name of the schema that the table belongs to and the identity of the database in which the table was created. The database ...
DROP TABLE TheDROP TABLEcommand deletes a table in the database. The following SQL deletes the table "Shippers": ExampleGet your own SQL Server DROPTABLEShippers; Note:Be careful before deleting a table. Deleting a table results in loss of all information stored in the table!
AI代码解释 ---Table structureforstudent---DROPTABLEIFEXISTS`student`;CREATETABLE`student`(`id`int(11)NOTNULLAUTO_INCREMENTCOMMENT'id',`sno`varchar(20)CHARACTERSETutf8COLLATEutf8_unicode_ciNULLDEFAULTNULLCOMMENT'学号',`sname`varchar(10)CHARACTERSETutf8COLLATEutf8_unicode_ciNULLDEFAULTNULLCOMMENT'学生...
The TRUNCATE TABLE statement is used to delete the data inside a table, but not the table itself.SyntaxTRUNCATE TABLE table_name; Exercise? What does the SQL DROP TABLE statement do? Deletes a table and all its data from the database Renames an existing table Copies a table and its ...
SELECT AddressID, AddressLine1, StateProvinceCode, CountryRegionCode FROM Person.AddrState WITH (SERIALIZABLE) WHERE StateProvinceCode = 'WA'; 查询将失败,因为在展开视图 SERIALIZABLE 时此查询中应用于该视图的提示 Person.AddrState 传播到了该视图中的表 Person.Address 和Person.StateProvince。 但是,展开...
CREATE TABLE [dbo].[data_retention_table] ( [dbdatetime2] DATETIME2 (7), [product_code] INT, [value] CHAR (10) ) WITH (DATA_DELETION = ON ( FILTER_COLUMN = [dbdatetime2], RETENTION_PERIOD = 1 WEEKS ) ); Y. 创建可更新的账本表 以下示例创建一个可更新的分类帐表,该表不是具有匿...
,"CREATE ROLE 1 error code: ",SQLCODE &sql(CREATE ROLE drone) w !,"CREATE ROLE 2 error code: ",SQLCODE &sql(GRANT workerbee,drone,%CREATE_TABLE,%DROP_TABLE TO NoahTest) w !,"GRANT角色和权限错误代码: ",SQLCODE } 下面的示例将当前命名空间中所有表上的所有7个基本权限授予所有当前定义的...
在 CREATE TABLE 或 ALTER TABLE 陳述式中為 FOREIGN KEY name 所指定的刪除規則無效, reason-code 指定的原因如下: 指定的刪除規則是 RESTRICT 或 SET NULL,參照關係會造成表格 table-name 本身連鎖刪除。 指定的刪除規則是 CASCADE,但在含有 RESTRICT 或 SET NULL 刪除規則的循環中,參照關係會造成表格 table...
DepartmentCode CHAR(3) COLLATE SQL_Latin1_General_CP1_CI_AS ) 与临时表的关键差异: 作用域限于批处理/函数/存储过程 不产生统计信息 更适合小数据集操作 三、高级创建技巧 3.1 动态创建方案 DECLARE @SQL NVARCHAR(MAX) = N'CREATE TABLE #DynamicTemp( Col1 INT, Col2 XML, CONSTRAINT CHK_Col1 CHE...
1.select子句中尽量避免使用* select子句中，*是选择全部数据的意思。比如语句：“select * from 成绩表...