Bài giảng Hệ quản trị cơ sở dữ liệu SQL Server - Lecture 8: How to insert, update, and delete data - Lê Thị Tú Kiên

Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 1 Lecture 8 How to insert, update, and delete data Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 2 Objectives Applied  Given the specifications for an action query, code the INSERT, UPDATE, or DELETE statement for doing the action.  Create a copy of a table by using the INTO clause of the SELECT statement. Knowledge  Describe the three types of action queries.  Explain how to handle null values and default values when coding INSERT and UPDATE statements.  Explain how the FROM clause is used in an UPDATE or DELETE statement. Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 3 The syntax of the SELECT INTO statement SELECT select_list INTO table_name FROM table_source [WHERE search_condition] [GROUP BY group_by_list] [HAVING search_condition] [ORDER BY order_by_list] Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 4 Create a complete copy of the Employee table SELECT * INTO EmployeeCopy FROM Employee; Create a partial copy of the Employee table SELECT * INTO RetireEmp FROM Employee WHERE YEAR(GETDATE())- YEAR(bdate)>60 Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 5 Create a table with summary rows SELECT DNo, SUM(Salary) AS SumOfSalaries INTO DepSumSalary FROM Employee GROUP BY DNo; Warnings  When you use the SELECT INTO statement to create a table, only the column definitions and data are copied.  Definitions of primary keys, foreign keys, indexes, default values, and so on are not included in the new table. Murach's SQL Server 2012, C7 © 2012, Mike Murach & Associates, Inc. Slide 6 The syntax of the INSERT statement INSERT [INTO] table_name [(column_list)] [DEFAULT] VALUES (expression_1 [, expression_2]...) [, (expression_1 [, expression_2]...)...] Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 7 The values for a new row in the Employee table Column Value FName Thanh Minit T LName Nguyen SSN 223344555 BDate 1980-08-15 Address 460 Dallas, Houston,TX Sex F Salary 35000 SuperSSN 888665555 DNo 4 Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 8 Insert the row without using a column list INSERT INTO EmployeeCopy VALUES ('Thanh', 'T', 'Nguyen', '223344555', '1980-08-15','460 Dallas, Houston,TX', 'F', 35000, 888665555,4); Insert the row using a column list INSERT INTO EmployeeCopy (FName, Minit,LName,SSN,BDate,Address, Sex,Salary,SuperSSN,DNo) VALUES ('Thanh', 'T', 'Nguyen', '223344555', '1980-08-15','460 Dallas, Houston,TX', 'F', 35000, 888665555,4); The response from the system (1 row(s) affected) Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 9 Insert three rows INSERT INTO Employee VALUES (N'Jonh ', N'B', N'Smith', N'123456789', CAST(0x21F20A00 AS Date), N'731 Fondren, Houston, TX', N'M', 30000, N'333445555', 5), (N'Franklin ', N'T', N'Wong', N'333445555', CAST(0x83050B00 AS Date), N'638 Voss, Houston, TX', N'M', 40000, N'888665555', 5), (N'Joyce ', N'A', N'English', N'453453453', CAST(0xE8FC0A00 AS Date), N'5631 Rice, Houston, TX', N'M', 25000, N'333445555', 5); The response from the system (3 row(s) affected) Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 10 The definition of the ColorSample table Column Data Allow Default Name Type Length Identity Nulls Value ID Int 4 Yes No No ColorNumber Int 4 No No 0 ColorName VarChar 10 No Yes No Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 11 Six INSERT statements for the ColorSample table INSERT INTO ColorSample (ColorNumber) VALUES (606); INSERT INTO ColorSample (ColorName) VALUES ('Yellow'); INSERT INTO ColorSample VALUES (DEFAULT, 'Orange'); INSERT INTO ColorSample VALUES (808, NULL); INSERT INTO ColorSample VALUES (DEFAULT, NULL); INSERT INTO ColorSample DEFAULT VALUES; Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 12 The ColorSample table after the rows are inserted Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 13 The syntax of the INSERT statement for inserting rows selected from another table INSERT [INTO] table_name [(column_list)] SELECT column_list FROM table_source [WHERE search_condition] Insert retire employees into the RetireEmp table INSERT INTO RetireEmp SELECT * FROM Employee WHERE YEAR(GETDATE()) - YEAR(bdate)>60 Note: The table RetireEmp must aready exist in the database COMPANY. Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 14 The same INSERT statement with a column list INSERT INTO RetireEmp (FName, Minit,LName,SSN,BDate, Address,Sex,Salary,SuperSSN,DNo) SELECT FName, Minit,LName,SSN,BDate, Address,Sex,Salary,SuperSSN,DNo FROM Employee WHERE YEAR(GETDATE()) - YEAR(bdate)>60 Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 15 The syntax of the UPDATE statement UPDATE table_name SET column_name_1 = expression_1 [, column_name_2 = expression_2]... [FROM table_source [[AS] table_alias] [WHERE search_condition] Update two columns of a single row UPDATE EmployeeCopy SET Salary = 40000, DNo = 5 WHERE SSN = '223344555'; Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 16 Update one column of multiple rows UPDATE EmployeeCopy SET DNo=3 WHERE DNo = 4; Update a column using an arithmetic expression UPDATE EmployeeCopy SET Salary = Salary + 1000 WHERE DNo = 3; Warning  If you omit the WHERE clause, all the rows in the table will be updated. Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 17 A subquery that returns the value assigned to a column UPDATE EmployeeCopy SET Salary = (SELECT AVG(Salary) FROM EmployeeCopy WHERE DNo = 5) WHERE SSN = '223344555'; Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 18 A subquery used in a search condition UPDATE EmployeeCopy SET Salary = Salary + 1000 WHERE DNo = (SELECT DNumber FROM Department WHERE DName = 'Research'); Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 19 A column in a joined table used in a WHERE clause UPDATE EmployeeCopy SET Salary = Salary + 1000 FROM EmployeeCopy JOIN Department ON DNo=DNumber WHERE DName = 'Research'; Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 20 The syntax of the DELETE statement DELETE [FROM] table_name [FROM table_source] [WHERE search_condition] Delete a single row from the EmployeeCopy table DELETE EmployeeCopy WHERE Ssn = '223344555'; (1 row(s) affected) Delete all the employees for a department DELETE EmployeeCopy WHERE Dno = 3; (3 row(s) affected) Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 21 Delete all the rows DELETE EmployeeCopy; Warning  If you omit the WHERE clause from a DELETE statement, all the rows in the table will be deleted. Murach's SQL Server 2012, C7 Le Thi Tu Kien – FIT - HNUE Slide 22 A subquery used in a search condition DELETE EmployeeCopy WHERE DNo = (SELECT DNumber FROM Department DName = 'Research') The same statement using a join DELETE EmployeeCopy FROM EmployeeCopy JOIN Department ON DNo=DNumber WHERE DName = 'Research';