change data type sql

length Date and time Date and time are entered separately in single quotation marks Datetime Date and time Bit data type Data that represents yes/no, there are only two options. In SQL Server 1 and 0 represent, General 1 means yes, 0 indicates no. Bit Storing B

Suppose there are stored procedures: proc_test2Create proc Proc_test2@Id intBeginAsDECLARE @sql varchar (max)@sql = ' SELECT * from test2 where 1=1 'If @Id Set @sql + = ' and Id = ' +@IdEXEC (@sql)EndThe parameters required by the stored procedure are of type int, and the di

Composite type A composite type can store multiple values, including records and collections. A set is one-dimensional, but it can be set into a multidimensional collection by putting other collections in it. The collection is divided into three kinds of index table, nested table and variable length array. To use a collection, we first create a collection type a

, 2079, with a precision of 1 minutes.SmallInt Supported by the. NET Compact Framework.Int16 A 16-bit signed integer.SmallMoney Supported by the. NET Compact Framework.Decimal A currency value ranging from -214,748.3648 to +214,748.3647, with a precision of 10 per thousand monetary units.Text Supported by the. NET Compact Framework.String Variable-length stream of non-Unicode data with a maximum length of 231-1 (or 2,147,483,647) characters.Timestamp

String 21st Binary data Binary Byte[] 22 varbinary Byte[] 23 Image Byte[] 24 Other uniqueidentifier Guid 25 Variant Object PS. Originally intended to reprint trackback:http://tb.blog.csdn.net/trackback.aspx?postid=95675 (SQL Server corresponds to the

expression1 or expression2 belongs to the Unicode data type (nvarchar or nchar) and the other does not, the other is converted to a Unicode data type. If one of the expression1 or expression2 is a null value, CHARINDEX returns a null value when the database compatibility level is 70 or greater. When the database compa

Text type:Char: fixed -length non- Unicode character data with a maximum length of 8,000 charactersVARCHAR: variable -length non- Unicode character data with a maximum length of 8,000 charactersText: Store long text messages with a maximum length of 231-1 (2147483647) charactersNCHAR: fixed-length Unicode character data with a maximum length of 4,000 charactersNV

Tags: blog http using file data IO problem htmlThis article originates from: http://www.cnblogs.com/zhhh/archive/2011/04/06/2006868.htmlA circular reference is detected when a data object is serialized using LINQ to SQL and a System.InvalidOperationException exception is reported, and an object of the type is serialize

1. Prepare the data files that need to be transferred and transfer them to the server2. Create a new target table in the databaseDROP TABLE lob_tab;CREATE TABLE lob_tab ( number_content NUMBER(10), varchar2_content VARCHAR2(100), date_content DATE, clob_content CLOB, blob_content BLOB);3. Write the control file for SQL loader (named: LOB_TEST.CTL)LOADDATA INFILE' Lob_test_data.txt '

if the amount of data is small, create a table and insert it in order to mitigate the resources of the system tables. If a temporary table is used, TRUNCATE TABLE first and then drop table when all temporary tables are finally explicitly deleted, which avoids longer locking of the system tables. Index You should first consider establishing an index on the columns involved in where and order by. When using an indexed field as a

1.Bit type: bit (1) don't think it's just a bit, in fact it's going to take up a byte! That means when n 2.varchar (n) here n cannot be greater than 8000, if you want to be larger than 8000 you can only specify varchar (max); Here's the same for nvarchar (n).What I don't understand is why 8000 is not 2 of the 16-time party! Why Max can be infinitely big!3.Sql_variant can think of it as an object type in C#/

Date Time Data type* System constants:@ @DATEFIRST (back to current time)DATEADDAdd TimeSyntax: DATEADD (datepart, number, date)Select DATEADD (year,2, ' 2013-11-2 ')DATEDIFFDistance between two datesSelect DATEDIFF (year, ' 2011-7-18 ', ' 2014-11-2 ')DatenameReturns a time value in which you want to get the number of a block typeSelect Datename (year, ' 2011-7-8 ')DATEPARTSelect DATEPART (Second, ' 2014-11