Java初学者必看的基础SQL查询语句Java初学者必看的基础SQL查询语句Java是一种面向对象的跨平台编程语言，下面小编整理了Java初学者必看的基础SQL查询语句，希望对大家有帮助!1、创建表和数据插入SQL我们在开始创建数据表和向表中插入演示数据之前，我想给大家解释一下实时数据表的设计理念，这样也许能帮助大家能更好的理解SQL查询。在数据库设计中，有一条非常重要的规则就是要正确建立主键和外键的关系。现在我们来创建几个餐厅订单管理的数据表，一共用到3张数据表，ItemMaster表、OrderMaster表和OrderDetail表。创建表：创建ItemMaster表：CREATETABLE[dbo].[ItemMasters]([Item_Code][varchar](20)NOTNULL,[Item_Name][varchar](100)NOTNULL,[Price]IntNOTNULL,[TAX1]IntNOTNULL,[Discount]IntNOTNULL,[Description][varchar](200)NOTNULL,[IN_DATE][datetime]NOTNULL,[IN_USR_ID][varchar](20)NOTNULL,[UP_DATE][datetime]NOTNULL,[UP_USR_ID][varchar](20)NOTNULL,CONSTRAINT[PK_ItemMasters]PRIMARYKEYCLUSTERED([Item_Code]ASC)WITH(PAD_INDEX=OFF,STATISTICS_NORECOMPUTE=OFF,IGNORE_DUP_KEY=OFF,ALLOW_ROW_LOCKS=ON,ALLOW_PAGE_LOCKS=ON)ON[PRIMARY])ON[PRIMARY]向ItemMaster表插入数据：INSERTINTO[ItemMasters]([Item_Code],[Item_Name],[Price],[TAX1],[Discount],[Description],[IN_DATE],[IN_USR_ID],[UP_DATE],[UP_USR_ID])VALUES('Item001','Coke',55,1,0,'Cokewhichneedtobecold',GETDATE(),'SHANU',GETDATE(),'SHANU')INSERTINTO[ItemMasters]([Item_Code],[Item_Name],[Price],[TAX1],[Discount],[Description],[IN_DATE],[IN_USR_ID],[UP_DATE],[UP_USR_ID])VALUES('Item002','Coffee',40,0,2,'CoffeMightbeHotorColduserchoice',GETDATE(),'SHANU',GETDATE(),'SHANU')INSERTINTO[ItemMasters]([Item_Code],[Item_Name],[Price],[TAX1],[Discount],[Description],[IN_DATE],[IN_USR_ID],[UP_DATE],[UP_USR_ID])VALUES('Item003','ChikenBurger',125,2,5,'Spicy',GETDATE(),'SHANU',GETDATE(),'SHANU')INSERTINTO[ItemMasters]([Item_Code],[Item_Name],[Price],[TAX1],[Discount],[Description],[IN_DATE],[IN_USR_ID],[UP_DATE],[UP_USR_ID])VALUES('Item004','PotatoFry',15,0,0,'NoComments',GETDATE(),'SHANU',GETDATE(),'SHANU')创建OrderMaster表：CREATETABLE[dbo].[OrderMasters]([Order_No][varchar](20)NOTNULL,[Table_ID][varchar](20)NOTNULL,[Description][varchar](200)NOTNULL,[I