Certifiably sql_ building tables _ database administration content from sql server pro

\[Editor’s Note: Each month, Certifiably SQL will cover topics you’ll need to understand to get your certification in SQL Server Administration and Implementation or Data Warehousing with SQL Server. Gif database The column includes an explanation of the topic and some questions that approximate what you might see on the MCDBA exams.\]

This month, I address one of the exam topics—building tables—from exam 70-29, the exam for the “Implementing a Database Design on SQL Server 7.0” course. Data recovery lifehacker In a forthcoming article, I’ll discuss constraints and integrity issues. Top 10 data recovery software 2014 As always in SQL Server, you have two options for building tables: the GUI and the Query Analyzer. Database gale I look first at the GUI, and then consider the use of the Query Analyzer. Database life cycle The GUI has changed in SQL Server 7.0, but it offers the same functionality as in the previous release plus some new features, so making the switch won’t take long.

To start the table builder interface from Enterprise Manager, select the database, right-click it, and select New, Table. Data recovery dallas Or in the database, select Tables, right-click, and select New Table. Data recovery usb Screen 1 shows the resulting Design Table window.

Database 4th normal form First, put spaces in table names, especially if you plan to use the same table definitions in a database on a different relational database management system (RDBMS). V database in oracle Even if you supply a name, SQL Server opens the Design Table window with the caption put spaces in table names, especially if you plan to use the same table definitions in a database on a different relational database management system (RDBMS). Data recovery tampa Even if you supply a name, SQL Server opens the Design Table window with the caption New Table in dbname on servername because it has not yet saved the table with the name you specified.

A table can have up to 1024 columns in SQL Server 7.0. R studio data recovery with crack A row can’t span pages, so the upper limit of the row size, adding all the column widths, is 8060 bytes. Database uses Columns using the char, varchar, binary, and varbinary data types can be up to 8000 bytes. Database history Column names can be up to 128 Unicode characters. Database b tree In the graphical interface, type in the name of the column. Database optimization (The note about spaces in object names also applies to the column names.) A new column defaults to character data, but you can select any available data type from a drop-down list. Data recovery software reviews Some data types, such as char and binary, require that you specify a length, but SQL Server supplies a default value (which you can override). Cnet data recovery Other data types, such as integer and datetime, are fixed length. Database systems For decimal and numeric data, add the precision (the total number of digits) and scale (the number of digits after the decimal point). Data recovery for mac In SQL Server 7.0, the graphical table builder’s default is to let a column contain nulls. Data recovery damaged hard drive Clear this check box to require the user to input a value for a column.

The table builder lets you specify a default value, which must match the data type, for each column. Database builder Also, you can select a column to be an identity column. Data recovery cnet The identity property means that the column automatically assigns values to rows as they are inserted, starting with the identity seed value and incrementing by the identity increment value. Database log horizon People often use this property to generate invoice numbers, order numbers, etc. Data recovery raid An identity column can’t contain null values and is often a primary key for the table.

New in SQL Server 7.0 is the option to designate a column as the RowGUID. Database design for mere mortals A Globally Unique Identifier (GUID) is unique not only in this table but also on all SQL Servers. Database hardening The GUID becomes useful when you look at some advanced features of SQL Server such as merge replication and OLAP Services. Data recovery linux distro The GUID identifies the row and its origin. Data recovery key Merge replication adds a column of this type if it doesn’t find one in a published table. Data recovery macbook And when you combine data from many sources into a data warehouse, you need to know where the data originated—especially if you’re making decisions based on this data.

Add each column, with the appropriate data type and other values, to the table. Data recovery los angeles You can designate one or more columns as the primary key for the table. Database yml The second icon on the Enterprise Manager toolbar, Table and Index Properties, brings up another dialog box, from which you can set the file group for the table and a file group for the text data, as you see in Screen 2. Database in excel You can even change the table name here. G info database Check constraints for table and columns is an option on this dialog box that I’ll cover in another column. Database book (Briefly, constraints limit the values or format of the data a user is allowed to input.) In the Relationships tab, you can set up primary-to-foreign key relationships between tables. Q prime database You use the third tab, Indexes/Keys, to define your indexes on the table. Top 10 data recovery tools Also, you can define the file group to place the index on. Data recovery laptop Some database designers prefer to place the tables and indexes on separate file groups on different physical disks to improve performance. Data recovery flash drive (You can design the database storage in such a way that while one set of disk heads is retrieving the index values, another set of disk heads is starting to return data rows to the user.)

The graphical interface is great for building tables, but what if you have to recreate the table on either the same server or a different server? Fortunately, you don’t need to repeat all the steps of typing column names and selecting options. Data recovery cost SQL Server can generate an SQL script that you can run from a Query Analyzer window to regenerate a table or even a complete database. Data recovery galaxy s5 You can bring up the script-generating dialog boxes in several ways. Database key field You can select a table, then right-click, and select All Tasks, Generate SQL Scripts. Data recovery nashville The scripting dialog box opens, as you see in Screen 3, with only that table selected, but you can add other tables and database objects to the list. Data recovery minneapolis To generate a script for the entire database, right-click on Databases and select All Tasks, Generate SQL Scripts. Database 4 net By default, this approach scripts all the tables. Iphone 6 data recovery software free You can turn on an option under the formatting tab to also generate scripts for the dependent objects that reference these tables. Database usa reviews In either case, you can add other objects to the script, including indexes, views, triggers, stored procedures, and security settings for logins and database users. Easeus data recovery 94fbr Save the script, preferably on another computer, in case disaster strikes. Database join If nothing else, the script documents what you built using the GUI.

Modifying a table is easy in SQL Server 7.0. H2 database download Select the table, right-click, and choose Design Table. H2 database url You can add columns, delete columns, and even change the column data types and sizes, with certain restrictions. Data recovery boot disk Also, you can change the nullability of a column. 990 database When you change a table, SQL Server can generate a change SQL script for you. Data recovery hard drive cost When rebuilding, run the script you generated, then run the change script to rebuild your database the way you want it. Data recovery knoxville Or, you can edit the original script to reflect the changes.

Knowing how to read, interpret, and write SQL scripts is useful, even if you use the GUI most of the time. 7 data recovery keygen For recreating a database, a script is much easier than the typing-and-clicking option. H2 database client For example, the script that creates the authors table in the Pubs database looks like this: USE pubs GO CREATE TABLE dbo.authors ( au_id varchar(11) NOT NULL , au_lname varchar(40) NOT NULL , au_fname varchar(20) NOT NULL , phone char(12) NOT NULL , address varchar(40) NULL , city varchar(20) NULL , state char(2) NULL , zip char(5) NULL , contract bit NOT NULL )

This script simply builds the table; each line adds a column to the table. Dayz database You can use Transact SQL (T-SQL) for creating indexes, adding constraints, and other features, all of which I’ll cover in future columns.

The author table example script specifies NULL or NOT NULL for each column. I phone data recovery Specifying nullability is a good habit to get into. Database 3d SQL Server defaults to NOT NULL for all columns. Yorku database However, ODBC and OLE DB applications set the null default to the ANSI standard, to allow nulls, which is why the GUI sets all the columns to allow nulls. O o data recovery (For more details on using NULLs, see SQL by Design, “The Reason for NULL,” page 65.) If you rely on the defaults, remember that you can change the default nullability for the server, the database, or the session you used to run the script.

For more practice, see the sidebar, “Practice Questions: Building Tables.” WebSQL subscribers can find a practice lab at the link to this article at http://www.sqlmag.com. Data recovery illustrator Also at this site, you can find references to books that can help you acquire the knowledge you need for certification.