Giáo trình SQL bài 17

... Chapter Faculty of Science and Technology Database Fundamentals Specifying Updates in SQL • There are three SQL commands to modify the database: INSERT DELETE UPDATE Faculty of Science and Technology ... taken when the condition is satisfied Faculty of Science and Technology Database Fundamentals 17 SQL Triggers: An Example • A trigger to compare an employee’s salary to his/her superv...

Ngày tải lên: 03/12/2015, 04:03

... Outlines SQL Server 20 08 Install guide Using T -SQL Faculty of Science and Technology Database Fundamentals SQL Server 20 05 Microsoft SQL Server 20 05 extends the performance, ... command to exit the SQLCMD utility: Exit Faculty of Science and Technology Database Fundamentals SQL Server Management Studio Start Programs SQL Server 20 08 Server Management Studio SQL Enter Pas...

Ngày tải lên: 03/12/2015, 03:50

... smallint tinyint Bytes Range -2 63 (-9,2 23, 372, 036 ,854,775,808) to 2 63 - (9,2 23, 372, 036 ,854,775,807) - 231 (-2,147,4 83, 648) to 231 - (2,147,4 83, 647) -215 ( -32 ,768) to 215 - (32 ,767) Faculty of Science ... Data types (3) Appropiate numeric Name Float[(n)] real Bytes Range n - 1.79E +30 8 to -2.23E -30 8, and 2.23E -30 8 to 1.79E +30 8 - 3. 40E + 38 to -1.18E - 38 , and 1.1...

Ngày tải lên: 03/12/2015, 03:50

... Completeness Constraint Faculty of Science and Technology Database Fundamentals 42 Constraints on Specialization and Generalization (4) • Disjointness Constraint: Specifies that the subclasses of the specialization ... Shown in EER diagrams by a single line Faculty of Science and Technology Database Fundamentals 44 Specialization/Generalization Hierarchies, Lattices & Shared Subclasses • A...

Ngày tải lên: 03/12/2015, 03:50

... Stafford DNum 5 4 DNo 5 5 4 Lab 02 Company Database • Works on ESSN PNo 123 456 789 123 456 789 3334 455 55 3334 455 55 3334 455 55 3334 455 55 453 453 453 453 453 453 666884444 8886 655 55 987 654 321 987 654 321 987987987 ... Smith 123 456 789 01/09/1 955 Houston, M 30000 3334 455 55 TX Franklin T Wong 3334 455 55 12/08/19 45 Houston, M 40000 8886 655 55 TX Joyce A English 453...

Ngày tải lên: 03/12/2015, 03:58

... employee for all projects he or she works on is 56 hrs per week” • A constraint specification language may have to be used to express these • SQL- 99 allows triggers and ASSERTIONS to express ... Faculty of Science and Technology Database Fundamentals 44 ER-to-Relational Mapping Algorithm (6) • Step 6: Mapping of Multivalued attributes For each multivalued attribute A, create a new relatio...

Ngày tải lên: 03/12/2015, 03:58

... number of tuples in the input relation R Faculty of Science and Technology Database Fundamentals 10 Example of Select • σ(Dno=4 AND Salary>25000) OR (Dno=5 AND Salary> 30000)(EMPLOYEE) Faculty

Ngày tải lên: 03/12/2015, 03:58

Ngày tải lên: 03/12/2015, 03:58

... condition>S = σ (R X S) Faculty of Science and Technology Database Fundamentals 12 Binary Relational Operations: DIVISION • DIVISION Operation The division operation is applied ... Technology Database Fundamentals 32 Languages Based on Tuple Relational Calculus • The language SQL is based on tuple calculus It uses the basic block structure to express the queries in tuple ... needed in th...

Ngày tải lên: 03/12/2015, 03:59

Ngày tải lên: 03/12/2015, 03:59

... W06_FD_Lab14_The_Relational_Algebra_2.doc 2/2 (d) For each book that is loaned out from the "Sharpstown" branch

Ngày tải lên: 03/12/2015, 03:59

... Database Fundamentals 16 NULLS In Sql Queries • SQL allows queries that check if a value is NULL (missing/not known or undefined/withheld or not applicable/not apply) • SQL uses IS or IS NOT to compare ... and AVG • Query 15: Find the maximum salary, the minimum salary, and the average salary among all employees Q15: SELECT FROM MAX(Salary), MIN(Salary), AVG(Salary) EMPLOYEE • Some SQ...

Ngày tải lên: 03/12/2015, 03:59

Ngày tải lên: 03/12/2015, 03:59

... SMALLINT DATETIME DATETIME Null – PK NOT NULL NOT NULL NOT NULL Note: Save to file Library_Tab .sql W09_FD_Lab04_Libary.doc Insert Data • Publisher Name Address Phone Amazing Books 9012 Great ... 12/15/2005 NULL 2 11/24/2005 NULL 12/15/2005 NULL 11/19/2009 NULL Note: Save to file Library_Data .sql

Ngày tải lên: 03/12/2015, 06:45

... separate query blocks • Aggregate operators in SQL must be included in the extended algebra Faculty of Science and Technology Database Fundamentals Translating SQL Queries into Relational Algebra (2) ... Introduction to Query Processing (2) Faculty of Science and Technology Database Fundamentals Translating SQL Queries into Relational Algebra • Query block: The basic unit that can be tr...

Ngày tải lên: 03/12/2015, 06:45