Chapter 6-2 MS SQL Server (Cont.) Learn how to create databases with SQL Server 2000 Creating a table with SQL Server 2000

Transcription

1 Chapter 6-2 MS SQL Server (Cont.) Learn how to create databases with SQL Server 2000 Creating a table with SQL Server

2 Learn how to create databases with SQL Server 2000 SQL Server Identifiers Identifiers can be from 1 to 128 Unicode characters in length including letters, symbols, and numbers. The first character must be a letter or the following #, or _ (underscore). You can use the following symbols after the first character: #, $, and _. Identifiers that begin with symbol are used as local variables. Identifiers that begin with the # symbol are used to signify that the object you are creating is a temporary object and can be referenced by the user during the session. SQL Server Database 2

3 Creating a database With SQL Server 2000, you can create databases using one of these three methods: The Create Database Wizard The SQL Server Enterprise Manager console Transact SQL (T-SQL) Using the Create Database Wizard If you're new to SQL Server, the best way to create a new database is to use the Create Database Wizard. Once you are comfortable with using SQL Server Enterprise Manager and/or T-SQL, you can move beyond this wizard to more advanced ways of creating databases. To use the Create Database Wizard: 1. Open the SQL Server Enterprise Manager from the Start menu. 2. Click on the SQL Server instance where you want to create your new database and expand it (using the plus sign to the left). 3. From the Tools menu, choose Wizards. 4. Expand Database and highlight Create Database Wizard (Figure A) and click OK. 3

4 5. When the Welcome To The Create Database Wizard screen appears, click Next, type a database name, and browse to the location where you want to place your database file and transaction logs (Figure B). (Figure B) 6. Click Next and enter the initial size of your primary database (.mdf) file (Figure C). You can add secondary files as well; they will be given an.ndf extension 4

5 7. Click Next and define how you want your database growth to occur (Figure D). 8. Click Next and enter the initial size of your transaction logs. 9. Click Next and define your transaction log database growth. 10. Click Next, review your database settings, and click Finish Manually create a database in Enterprise Manager To manually create a database using SQL Server Enterprise Manager: 1. Open Enterprise Manager and select and expand your SQL Server instance. 2. Right-click on Databases and choose New Database. 3. In the General tab, type a database name (Figure E). 5

6 4. In the Transaction Log tab, you can configure the auto growth size, database log location, and secondary location. 5. Click OK, and your database is created. Creating a database using T-SQL In addition to the two methods mentioned above, you can use T-SQL to create a database. The syntax is as follows: CREATE DATABASE database_name [ ON [ < filespec > [,...n ] ] [, < filegroup > [,...n ] ] ] [ LOG ON { < filespec > [,...n ] } ] [ COLLATE collation_name ] [ FOR LOAD FOR ATTACH ] < filespec > ::= [ PRIMARY ] ( [ NAME =logical_file_name, ] FILENAME ='os_file_name' [, SIZE =size ] [, MAXSIZE = { max_size UNLIMITED } ] [, FILEGROWTH =growth_increment ] ) [,...n ] < filegroup > ::= FILEGROUP filegroup_name < filespec > [,...n ] Let s say, for example, that we wanted to create a database that contains a primary data file called DDAT and one transaction log called DDAT_LOG. We would create this database using the T-SQL syntax shown in Figure G. 6

7 Now, we will take it one step further and add a primary file, two secondary files, and two transaction logs (Figure H), REF: 7

8 Creating a table with SQL Server 2000 Creating a table With SQL Server 2000, you can create tables using one of these three methods: The SQL Server Enterprise Manager console Transact SQL (T-SQL) Using the SQL Server Enterprise Manage Console Category Data Type Comments String char(n), varchar Stores character strings. Binary binary(n), varbinary Stores binary information in two-byte pairs. Integer int, smallint,tinyint Stores integer values. ApproxNumeric float, real Stores approximate numeric information. Exact Numeric decimal, numeric Stores exact numeric information. Special bit, text, image Stores a single bit, character information greater than 8,000 bytes, or image data. Date and Time Money datetime, smalldatetime money, smallmoney Stores dates and times. Stores currency values. Auto-increment timestamp Stores values that are automatically incremented. User-defined Computedcolumn Unicode data nchar, ntext, nvarchar You can create your own data types. Stores the expression used to compute the column. Stores data in a Unicode (double byte per stored character) format. 8

9 Using Transact SQL (T-SQL) Syntax CREATE TABLE [database.[owner.]]table_name ( column_name datatype [identity constraint NULL NOT NULL] [...] ) table_name column_name datatype The last piece is optional is the name of the new table following the rules for identifiers. It must also be unique within the database for its owner. This means that if two users have permission to create tables within a database, the tables themselves might have the same name, but they will still be considered unique because the owner s name forms part of the table name. is the column name and must follow the rules for identifiers is the data type of the column. You can specify the Identity property, field constraints, and nullability. Example 1 CREATE TABLE employees ( emp_id tinyint IDENTITY NOT NULL, Fname char(15), Lname char(20) NOT NULL, Address1 varchar(30), Address2 varchar(30), city varchar(30), state char(2), zipcode char(10), start_date datetime ) Example 2 CREATE TABLE tblorder ( OrdID int NOT NULL, Price money NOT NULL, 9

10 Qty smallint NOT NULL, Total AS Price * Qty ) Drop Tables To drop a table using Transact-SQL, run the DROP TABLE statement. Example 3 DROP TABLE tblemployees 10