设有关系数据：PART（PART_NO,PART_NAME)PROJECT（PROJECT_NO,PROJECT_NAME)SUPPLIER（SUPPLIER_NO

设有关系数据：

PART(PART_NO,PART_NAME)

PROJECT(PROJECT_NO,PROJECT_NAME)

SUPPLIER(SUPPLIER_NO,SUPPLIER_NAME,CITY)

SUPPLY(PART_NO,PROJECT_NO,SUPPLIER_NO,QUANTITY)

其中PART,PROJECT,SUPPLIER,SUPPLY分别表示零部件、工程、供货商和供货四个关系，关系中各属性的含义是：PART_NO(工程编号，主键);PART_NAME(零件名称);PROJECT_NO(工程编号，主键);PROJECT_NAME(工程名称);SUPPLIER_NO(供货商编号，主键);SUPPLIE_NAME(供货商名称);CITY(供货商所在城市);QUANTITY(供货量)

(1)用关系代数表达式表示如下询问：找出使用了长沙的供货商所供零部件的所有工程的名称。

(2)用SQL语言表示(1)中的询问

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更多“设有关系数据：PART（PART_NO,PART_NAME)PROJECT（PROJECT_NO,PROJECT_NAME)SUPPLIER（SUPPLIER_NO”相关的问题

第1题

Given the following DDL for the PARTS table:CREATE TABLE parts （part_no INT（9) NOT NULL, p

Given the following DDL for the PARTS table:CREATE TABLE parts (part_no INT(9) NOT NULL, part_name VARCHAR(24), part_remain INT(9));All part numbers entered will be different and all rows should be displayed in order of increasing part numbers whenever the table is queried. Which of the following create index statements will meet this criteria and require the least amount of storage for the index object？（）

A.CREATE UNIQUE INDEX idx_partno ON parts(part_no)

B.CREATE UNIQUE INDEX idx_partno ON parts(part_name ASC)

C.CREATE UNIQUE INDEX idx_partno ON parts(part_name, part_no ASC)

D.CREATE UNIQUE INDEX idx_partno ON parts(part_no, part_name ASC)

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第2题

设有关系模式R（A，B，C，D)，其数据依赖集：F={（A，B)→C，C→D}，则关系模式R不满足（)。

A.1NF

B.2NF

C.3NF

D.BCNF

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