create view语句是将某个查询数据的定义保留下来,以便随时调用,这就是所谓的视图。视图本身不存储查询结果,只是一个定义。 Syntax:CREATE[ORREPLACE] [ALGORITHM={UNDEFINED|MERGE|TEMPTABLE}] [DEFINER={user|CURRENT_USER}] [SQLSECURITY { DEFINER|INVOKER }]VIEWview_name [(column_list)]ASselect_statement [WI...
SQLCREATEORREPLACEVIEWSyntax CREATEORREPLACEVIEWview_nameAS SELECTcolumn_name(s) FROMtable_name WHEREcondition SQL 撤销视图 您可以通过 DROP VIEW 命令来删除视图。 1 2 SQLDROPVIEWSyntax DROPVIEWview_name 视图实际应用 在EF框架中,涉及多表联合查询的明细列表来说,使用视图是优化查询速度最有效的方法之一。
SQL CREATE OR REPLACE VIEW Syntax CREATEORREPLACEVIEWview_nameAS SELECTcolumn1,column2, ... FROMtable_name WHEREcondition; The following SQL adds the "City" column to the "Brazil Customers" view: Example CREATEORREPLACEVIEW[Brazil Customers]AS ...
SQL CREATE OR REPLACE VIEW Syntax CREATE OR REPLACE VIEW view_name AS SELECT column_name(s)FROM table_name WHERE condition 现在，我们希望向 "Current Product List" 视图添加 "Category" 列。我们将通过下列 SQL 更新视图：CREATE VIEW [Current Product List] AS SELECT ProductID,ProductName,Category FR...
IF NOT EXISTS(select * FROM sys.views where name = 'data_VVVV ') BEGIN CREATE VIEW data_VVVV AS SELECT VCV.xxxx, VCV.yyyy AS yyyy, VCV.zzzz AS zzzz FROM TABLE_A VCV END ELSE BEGIN ALTER VIEW data_VVVV AS SELECT VCV.xxxx, VCV.yyyy AS yyyy, VCV.zzzz AS zzzz FROM TABLE_A VCV ...
Transact-SQL syntax conventions Syntax Syntax for SQL Server and Azure SQL Database. syntaxsql CREATE[ORALTER]VIEW[schema_name. ]view_name[ (column [ ,...n ] ) ] [WITH<view_attribute>[ ,...n ] ]ASselect_statement[WITHCHECKOPTION] [ ; ]<view_attribute>::={ [ENCRYPTION] [SCHEMABINDI...
-- SQL CREATE VIEW 语法CREATE VIEW view_name AS SELECT column_name(s) FROM table_name WHERE condition -- SQL CREATE OR REPLACE VIEW 语法[CREATE|REPLACE] VIEW view_name AS SELECT column_name(s) FROM table_name WHERE condition -- SQL DROP VIEW 语法DROP VIEW view_name -- SQL Server --...
syntaxsql 复制 CREATE [ OR ALTER ] FUNCTION [ schema_name. ] function_name ( [ { @parameter_name [ AS ] [ type_schema_name. ] parameter_data_type [ NULL ] [ = default ] [ READONLY ] } [ , ...n ] ] ) RETURNS return_data_type [ WITH <function_option> [ , ...n ]...
syntaxsql 複製 CREATE [ OR ALTER ] FUNCTION [ schema_name. ] function_name ( [ { @parameter_name [ AS ] [ type_schema_name. ] parameter_data_type [ NULL ] [ = default ] [ READONLY ] } [ , ...n ] ] ) RETURNS return_data_type [ WITH <function_option> [ , ...n ] ]...
hive> CREATE TABLE pokes (foo INT, bar STRING); 创建外部表: CREATE EXTERNAL TABLE page_view(viewTime INT, userid BIGINT, page_url STRING, referrer_url STRING, ip STRING COMMENT 'IP Address of the User', country STRING COMMENT 'country of origination') ...