types of cursor in sql server

Ext.: http://www.cnblogs.com/pangpanghuan/p/6432331.htmlSQL Server Add fields, modify fields, modify types, modify default values1. Modify the field name:ALTER TABLE name rename column A to B2. Modify the field type:ALTER TABLE name ALTER COLUMN field name type NOT NULL3. Modify the field default valueALTER TABLE name add default (0) for field name with valuesIf the field has a default value, you need to re

factors on a pair of results. Model the relationship between the input and the output. To measure the impact of each input on the output and weigh the role of different inputs in the completed model. 9. Linear Regression algorithm Linear regression algorithm is a commonly used method for statistic and prediction, which makes a variant of decision Tree algorithm, helps to calculate the linear relation between dependent variable and independent variable, estimates the best linear equation of pred

that a transaction is reading. The row range for the first read of a transaction shows that one row has ceased to exist in the second or subsequent read because the row has been deleted by another transaction. Similarly, because of the insert operation of another transaction, the second or subsequent read of the transaction shows a row that does not exist in the original read.All four of these problems can cause inconsistencies in the data. The level at which we prepare transactions to accept i

SQL Server 2008 finally released the new version, although it was just another community beta rather than a full version. Whenever new software is released, the most problematic question to ask most is: What are some of the new features? SQL Server 2008 has many new features and new tools. However, this article is inte

: Rounding to the nearest value, rounding up, downloading, and rounding to zero. Microsoft SQL Server uses top rounding. All values must be accurate to the specified precision, but small floating point values may change. Because the binary representation of floating point numbers can use any of the many valid rounding rules, it is impossible for us to reliably quantify a floating point value.Convert decimal

sql-server Common data typesAuthor statement:The first time to write a blog, there are some deficiencies, and then I first involved in software development this industry, is a small white, the article will certainly appear some wrong place, hope to find the wrong friends can timely point out, insufficient places also please all the way the great God to teach, so I reference and study, thank you.integer data

Format description: Data Type Description Same meaning Bit 1 bit; Value: 0 or 1 Int Integer 4 bytes; value range:-2 ^ 31 ~ 2 ^ 31-1 Smallint 2 bytes; value range:-2 ^ 15 ~ 2 ^ 15-1 Tinyint 1 byte; value range: 0 ~ 255 Decimal (P, S) Numeric data with a fixed precision of P and a width of S Numeric Money 8 bytes, which stores the currency type; value range:-2 ^ 63 ~ 2 ^ 63-1 Small money 4 bytes, which stores the currency type. The value ranges from-214748.3648 ~ + 214748.3647 approximate numeric

The data types in SQL Server 2005 are grouped into the following categories: Exact number bigint Decimal Int Numeric smallint Money tinyint SmallMoney Bit Approximate numbers Float Real Date and time Datetime smalldatetim

bytes.Category five: String dataChar: Length is set, with a minimum of 1 bytes and a maximum of 8,000 bytes. The insufficient length will be blank.VARCHAR: The length is also set, the shortest is 1 bytes, the longest is 8,000 bytes, the trailing blanks will be removed.Text: Long-width is also set, the longest can be stored 2G of data.Category six: Unincode string dataNCHAR: The length is set, the shortest is 1 bytes, and the maximum is 4,000 bytes. The length of the gap is blank. Storing one ch

Tags: io file data SP C on r AD BSThe 1th type:DB Entire DatabaseThe 2nd type:File Database filesThe 3rd type:TableThe 4th type:HOBt (heap) BTree (b-Tree)The 5th type:Extent a district (8 8KB pages)The 6th type:Page data pages.The 7th type:The RID row identifier.The 8th type:Key is used to prevent phantom reading of the index line.The 9th type:Object Database objects.The 10th type:Application application-specific resources.The 11th type:Metadata system Meta dataThe 12th type:Allocateion unit A s

, with a minimum of 1 bytes and a maximum of 8,000 bytes. The insufficient length will be blank.VARCHAR: The length is also set, the shortest is 1 bytes, the longest is 8,000 bytes, the trailing blanks will be removed.Text: Long-width is also set, the longest can be stored 2G of data.Category six: Unincode string dataNCHAR: The length is set, the shortest is 1 bytes, and the maximum is 4,000 bytes. The length of the gap is blank. Storing one character requires 2 bytes.Nvarchar: The length is set

Label:Differences between text and varchar (max) data types in SQL ServerIt was only known that text and image were data types that could be retired by SQL Server, but it was not clear why the difference between text and varchar (max) and nvarchar (max) was found in reading

8000Varchar: Variable Length non-Unicode bytes data, maximum length: 8000Text: Variable Length non-Unicode bytes data. The maximum length is 2 ^ 31-1 (2G)Nchar: bytes data with a fixed length of Unicode. The maximum length is 8000.Nvarchar: variable-length Unicode bytes. The maximum length is 8000.Ntext: String-type data with Extended Unicode length. The maximum length is 2 ^ 31-1 (2G)Binary: binary data with a fixed length. The maximum length is 8000.Varbinary: variable-length binary data with

SQL Server 2005 compact edition books online Ing Data Types of ole db (SQL Server compact Edition) SQL Server 2005 compact edition converts the ole db data type to the local

Differences between text and varchar (max) data types in SQL ServerIt was only known that text and image were data types that could be retired by SQL Server, but it was not clear why the difference between text and varchar (max) and nvarchar (max) was found in reading today,

READ (SQL Server default level ). Repeatable read --- repeatable read. SERIALIZABLE --- SERIALIZABLE read (the highest level of transaction isolation, full isolation between transactions ). The following table (1) lists four isolation levels that allow different types of behavior. Isolation level Dirty read Cannot be read repeatedly Phantom

Server data type Description Synonymous Bit 1 digits, value 0 or 1 Int Integer 4 bytes, value is -2^31~2^31-1 Smallint 2 bytes, value is -2^15~2^15-1 Tinyint 1 bytes, value is 0~255 Decimal (P,s) numeric data, with a fixed precision of p, and a width of s Numeric Money 8 bytes, store currency type, value is -2^63~2^63-1 Small Money 4 bytes, store currency type, value is -214748.3648~+214748.3647 approximate numeric data type Float (N) n between 1~24,

Unicode Character Set is generated to solve the incompatibility problem of character sets. All its characters are expressed in two bytes, that is, English characters are also expressed in two bytes. If you are still struggling with this issue, let's take a look at the explanation below and make a decision. Generally, if you use Chinese characters or other special characters, I will use the type starting with n. Otherwise, I will directly start with var. What is the difference between varchar an

Tags: http ar data Art EF as TT htm SQLThe SQL Server string is divided into different types, and you will be presented with a few common types of SQL Server strings that you can use to help you learn

type [dbo]. [ContactStruct] as table ( [ContactID] [uniqueidentifier] not null, [FirstName] [nvarchar] (80) not null, [LastName] [nvarchar] (80) not null, [Email] [nvarchar] (80) not null, [Phone] [varchar] (25) not null, PRIMARY KEY CLUSTERED ( [ContactID] ASC ) WITH (IGNORE_DUP_KEY = OFF) ) GO SQL Server Management Studio displays the following results: Now we start to use User-Defined table