c# generate barcode free DATA TYPES, TABLES, AND CONSTRAINTS in Font

Print Code 39 in Font DATA TYPES, TABLES, AND CONSTRAINTS

CHAPTER 4 DATA TYPES, TABLES, AND CONSTRAINTS
Code 39 Maker In None
Using Barcode creator for Font Control to generate, create Code 39 Extended image in Font applications.
www.OnBarcode.com
UPC-A Supplement 5 Printer In None
Using Barcode generator for Font Control to generate, create UPC-A Supplement 2 image in Font applications.
www.OnBarcode.com
The first three INSERT statements are valid because they contain unique int1 column values. The fourth INSERT statement has a missing int1 column value. Because int1 serves as the primary key for the table, the missing value causes the rejection of the whole row. The fifth INSERT statement specifies an int1 column value of 3, but the third INSERT statement previously added a row to the table with this value. Therefore, SSE rejects the row for the fifth INSERT statement because it has a duplicate primary key value. INSERT INSERT INSERT INSERT INSERT T T T T T (int1, (int1, (int1) (bit1) (int1, bit1) VALUES (1, 1) bit1) VALUES (2, 0) VALUES (3) VALUES (1) bit1) VALUES (3,1)
Generating EAN 13 In None
Using Barcode creation for Font Control to generate, create EAN / UCC - 13 image in Font applications.
www.OnBarcode.com
EAN128 Drawer In None
Using Barcode generation for Font Control to generate, create UCC-128 image in Font applications.
www.OnBarcode.com
The following listing shows the result of running the script in Ch04UsingPrimaryKey.sql. A SELECT statement for all the column values in each row within the table created by the preceding CREATE TABLE statement generates the following output (SELECT * FROM T). The first three INSERT statements succeed. Before the result set for the SELECT statement, you can see error messages returned by SSE. These error messages explain why two of the INSERT statements did not succeed. Msg 515, Level 16, State 2, Line 8 Cannot insert the value NULL into column 'int1', table 'ProSSEAPPSCh04.dbo.T'; column does not allow nulls. INSERT fails.The statement has been terminated. Msg 2627, Level 14, State 1, Line 9 Violation of PRIMARY KEY constraint 'PK__T__145C0A3F'. Cannot insert duplicate key in object 'dbo.T'. The statement has been terminated. int1 bit1 ----------- ----1 1 2 0 3 0
Generating Data Matrix ECC200 In None
Using Barcode generation for Font Control to generate, create Data Matrix image in Font applications.
www.OnBarcode.com
Encode QR Code ISO/IEC18004 In None
Using Barcode generation for Font Control to generate, create QR Code ISO/IEC18004 image in Font applications.
www.OnBarcode.com
Using the IDENTITY Column Property
Barcode Generation In None
Using Barcode maker for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
Make Intelligent Mail In None
Using Barcode creator for Font Control to generate, create 4-State Customer Barcode image in Font applications.
www.OnBarcode.com
It is common to specify an IDENTITY property for a column with an integer data type that serves as a primary key. The IDENTITY property causes SSE to assign sequential column values starting from a seed value in fixed increments. Although the default seed and increment values for the IDENTITY keyword are both 1, you can override either or both. To change the default seed and increment settings, merely specify IDENTITY(seedvalue, incrementvalue) instead of IDENTITY. When a column has an IDENTITY property setting, users do not have to specify a value for a column during the insertion of a new row because SSE automatically assigns a column value. If you attempt to insert a column value for a column with an IDENTITY property setting, SQL Server rejects the row by default. When you include an IDENTITY property setting for a column serving as the primary key, you do not have to worry about duplicate values because SQL Server automatically specifies sequentially unique values.
Paint Code 39 Full ASCII In Objective-C
Using Barcode creation for iPad Control to generate, create Code 39 image in iPad applications.
www.OnBarcode.com
Code-39 Generator In Java
Using Barcode drawer for Android Control to generate, create Code 39 image in Android applications.
www.OnBarcode.com
Tip
Making Code39 In VB.NET
Using Barcode encoder for Visual Studio .NET Control to generate, create ANSI/AIM Code 39 image in .NET applications.
www.OnBarcode.com
Barcode Creator In Objective-C
Using Barcode printer for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
The IDENTITY property applies only to columns that have an integer data type. You cannot use it with columns that have a char or varchar data type.
Reading PDF 417 In Visual Studio .NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
UPC - 13 Creation In None
Using Barcode generation for Office Excel Control to generate, create European Article Number 13 image in Excel applications.
www.OnBarcode.com
CHAPTER 4 DATA TYPES, TABLES, AND CONSTRAINTS
Printing PDF-417 2d Barcode In Java
Using Barcode generator for BIRT Control to generate, create PDF417 image in Eclipse BIRT applications.
www.OnBarcode.com
Barcode Scanner In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
The following excerpt from Ch04UsingIDENTITY.sql demonstrates the syntax for specifying an IDENTITY property for the int1 column. By not explicitly designating seed or increment values, the statement accepts the default value of 1 for both. The int1 column also serves as the table s primary key, and it has an int data type. The bit1 column has a bit data type with a NOT NULL constraint and its DEFAULT property set to 0. CREATE TABLE T ( int1 int IDENTITY PRIMARY KEY, bit1 bit NOT NULL DEFAULT 0 ) The next excerpt from Ch04UsingIDENTITY.sql shows three valid INSERT statements for the table generated by the CREATE TABLE in the sample file and one invalid INSERT statement. The first two statements merely assign values to the bit1 column. The third statement shows the syntax for not specifying any column values. The DEFAULT VALUES phrase in the INSERT statement tells SSE to use the default value for bit1. This is legitimate in this case because int1 has an IDENTITY property setting, which causes its column values to be assigned by SSE. bit1 has its DEFAULT property set to 0, which does not conflict with the column s NOT NULL constraint. The fourth INSERT statement fails because it attempts to assign a value to int1, which has an IDENTITY property. SQL Server Express does not by default permit a client application to set a value for an IDENTITY column. INSERT INSERT INSERT INSERT T T T T (bit1) VALUES (1) (bit1) VALUES (0) DEFAULT VALUES (int1, bit1) VALUES (4,1)
Decode Code 39 Extended In Visual Basic .NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
UPC A Creation In VB.NET
Using Barcode drawer for .NET Control to generate, create UPC Code image in .NET applications.
www.OnBarcode.com
The following listing shows the result of running the script in Ch04UsingIDENTITY.sql, which ends with SELECT * FROM T. Notice that the int1 column values start at one and increment by one for each valid row through three. An error message before the result set explains the problem with the fourth INSERT statement: that while it is technically possible to insert a value to a column with an IDENTITY property, IDENTITY_INSERT must be set to ON. By default, IDENTITY_INSERT is set to OFF.
EAN / UCC - 13 Generator In None
Using Barcode maker for Microsoft Word Control to generate, create UCC.EAN - 128 image in Word applications.
www.OnBarcode.com
QR Code ISO/IEC18004 Encoder In Java
Using Barcode creation for Java Control to generate, create QR image in Java applications.
www.OnBarcode.com
The syntax for turning IDENTITY_INSERT on is SET IDENTITY_INSERT databasename.schemaname. Tip tablename ON. The syntax for restoring IDENTITY_INSERT s default status is SET IDENTITY_INSERT databasename.schemaname.tablename OFF. Specifying databasename and .schemaname qualifiers for the tablename argument is optional. While IDENTITY_INSERT is ON, you enable the insertion of values to the IDENTITY column for only one table in a database namely, the tablename argument value.
Msg 544, Level 16, State 1, Line 9 Cannot insert explicit value for identity column in table 'T' when IDENTITY_INSERT is set to OFF. int1 bit1 ----------- ----1 1 2 0 3 0
Copyright © OnBarcode.com . All rights reserved.