SSD7_Exam2 [Normalization, E-R Mapping]

SSD7_Exam2 [Normalization, E-R Mapping]

Algorithm language 4 years ago (2015-06-10) Views: 2 Comments: 0

1. The following table shows which parts suppliers can provide.The ID and name of the supplier can be found by the ID of the part.It is worth noting that one part can be provided by multiple suppliers, and one supplier can provide multiple parts PartID PartName SupplierID SupplierName 1234 Nut 223 ProMetal 1234 Nut 224 Biscayne 2134 Bolt 223 ProMetal 2. The following E-R relational model is transformed by the E-R mapping algorithm.Map in accordance with the nine steps of exercise seven, clearly marked each step, without this step this sign "None"   a) Normalization 1. PK (PartID, SupplierID) 2.FD (PartID->PartName, SupplierID->SupplierName) 3. This table belongs to the first normal form (1NF), because the above relationship, PartID, PartName, SupplierID, SupplierName and other components Inseparable data items. At the same time, it does not satisfy the second paradigm's non-primary attribute completely dependent on the code. 4. Step 1: From 1NF to 2NF (depending on the code): In the above relational model, because of PartID->PartName(F), SupplierID->SupplierName(F), the above relational schema should be split into three. Relational pattern 1Part (PartID, PartName) PK (PartID); FD (PartID->PartName) (F: complete function dependency) 2Supplier (SupplierID, SupplierName) PK (SupplierID) FD (SupplierID->SupplierName) (F: complete function Dependent on) 3SP (SupplierID,

SSD7_EX3 (Advanced SQL)

SSD7_EX3 (Advanced SQL)

Algorithm language 4 years ago (2015-05-11) Views: 5 Comments: 0

This is EX3 of SSD7 practice. It is expected that the extreme guests will write a series. The update frequency will be synchronized with the 2013 level progress of NWPU database system experiment class.Click the tab or search "SSD7" on this site to get the updated SSD7 answer.Previous exercise: SSD7_EX2 [SQL] The original title summary: This exercise uses the library schema of the library as a case. The case includes library books information, library member information, library loan information (a book is borrowed several times by a certain reader), publisher information provided by the book, publishing house order information.To distinguish from other exercises, the last character of each relationship name in this exercise is the Arabic numeral ‘4’. Create all your relationships using the SQL statements provided by CREATE TABLE and INSERT statements. You need to run the provided SQL statements in an empty database to create the database. English: For this exercise, we will use the library schema. It includes information about book titles in the library, information about library members, about the number of times the books were read by members, about the suppliers who supply books to the library, and about orders placed with the suppliers. To

SSD7_EX2 [SQL]

SSD7_EX2 [SQL]

Algorithm language 4 years ago (2015-04-30) Views: 2 Comments: 0

This is the EX2 of the SSD7 practice. It is expected that the extreme guests will write a series. The update frequency will be synchronized with the 2013 level progress of the NWPU database system experiment class.Click the tab or search "SSD7" on this site to get the updated SSD7 answer.Previous Exercise: SSD7_EX1 [Relational Database] Run a given SQL script to create a library database.Note that each row in the Book table refers to a copy of a book. Therefore, if a database has three "DBMSs", then the Book table will have three rows, one for each row. Write SQL statements to accomplish the following operations.(Note: For each operation, you must use a SQL statement to express your query. However, a statement can contain subqueries.) Original: Run the SQL script given to you to create a Library database. Note that each row in the Book table markeds a book copy. Thus, if the Library carries three copies of the title "DBMS", there will be three rows in the Book table, one for each copy. Write the SQL statements to do the following against the database (Note: You must express your query in a single SQL statement for each of the

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