alter table add column sql server

must be greater than 0-----ALTER TABLE subject with NOCHECKAdd constraint ck_classhour check (classhour > 0)-----Add a primary foreign key constraint to the grade grade table----ALTER TABLE subject with NOCHECKAdd constraint Fk_g

During database design, sometimes attribute record values belonging to the same person are stored in multiple records for the purpose of data standardization, you want to merge multiple attribute data into one row for display. This is a row-to-column conversion. For example, the score table. What is the efficiency of Row-to-column conversion? I tried the f

Tags: plsql developer text EditingOriginal works, from the "Blue Blog" blog, Welcome to reprint, please be sure to indicate the following sources, otherwise, the legal responsibility to pursue copyright.Deep Blue Blog:http://blog.csdn.net/huangyanlong/article/details/41513537Experiment: Use PL/SQL developer software to get the text form of table name and column n

exec sp_columns tableNameThe above line of code can find out all of the table column, instead of Sp_pkeys, you can find the table's primary key.But if I want to only find out the COLUMN name,select column_name from (exec sp_columns tableName) as A, it is not possible to write, you must create a table, insert data into

Tags: sys http alt compute VIA--mount Ges StudioThe computed column differs from the column that requires us to assign the value manually or by the program, whose value is derived from the computed value of the other columns in the table. For example, if a table contains a quantity

obvious effect, if interested can use large table for performance testing; Other One thing I'm surprised about is why is the "included columns" not available when modifying a table? Can I write this class index only through commands? Another point I would like to say, Microsoft's MSDN is indeed the best learning tool, the search on the internet is a lot of things are repeated, and said no

However, Microsoft SQL Server has an important flaw in processing such indexes, which is to index the operations that should be compiled into the index seek, which can cause severe performance degradation Let me give you an example to illustrate the problem. Assuming that a table T has an index (Cityid, Sentdate, UserID), and now has a paging list feature, to ob

Tags:--fetch stat sel SQ varchar col Char where--Declaring the necessary variablesDECLARE @tablename NVARCHAR, @columnname NVARCHAR (@sql NVARCHAR), @sql2 NVARCHAR (@sql3 NVARCHAR) ( , @CName NVARCHAR (20)SET @CName = ' Regioncode '--CursorsDECLARE cur CURSOR for--1, finding a table that contains a columnSELECT ' [' +table_schema+ ']. [' +table_name+ '] ' as TableName, ' [' +column_name+ '] 'from [Informati

Select A.name as table name, b.name as column name, c.name as type, b.max_length as Byte count, b.precision As Integer, B.scale as decimal from Sys.tables a INNER JOIN Sys.columns B on a.object_id=b.object_id inner join Sys. Types C on c.user_type_id=b.user_type_idThis article is from the "IT" blog, so be sure to keep this source http://8577754.blog.51cto.com/8567754/1553205How to use a statement in an

Tags: set l database collect text code span ret CTI Lin usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text; namespace_03 Major Item { Public classDeskinfo {//Deskid, Deskname, Desknamepinyin, Deskdelflag, Desknum Private int_deskid; /// ///the ID of the dining table/// Public intDeskid {Get{return_deskid;} Set{_deskid =value;} } Private string_deskname; /// ///the name of the

table variable, insert a piece of data, and then query: DECLARE @tb1 Table ( Id int, Name varchar, age int ) inserts into @tb1 VALUES (1, ' Liu Bei SELECT * from @tb1 The output results are as follows: 　　 Try something that doesn't meet your requirements, such as adding a table variable, adding a constraint, and naming the constraint: Try so

(*) from syscolumnsWhere id = (select id from sysobjects where type = 'U' and name = 'your table name ')And name = 'field name to be judged'A small example-- Assume that the table to be processed is named tb.-- Determines whether the table to be added has a primary key.If exists (select 1 from sysobjects where parent_obj = object_id ('tb') and xtype = 'pk ')Begi

However, Microsoft SQL server has an important defect in processing such indexes, that is, the operations that should have been compiled into index seek are compiled into index scanning, which may cause serious performance degradation.For example, assume that a table T has an index (cityid, sentdate, userid) and now has a paging list function, to query several re

supplier 25h48911000023 Black Fountain refill 2.000 422 232 3425h52921000088 Scissors 4.000 342 434 3245h57161000002 Calculator 2.000 211 2432 234The use of pivot is a simple implementation of the column change, for similar data processing gray often practical, avoid the use of case or circular cursor complex processing, greatly improve the processing speed and code neat and elegant.Precautions : 1. When you use PIVOT and UNPIVOT for a database that

, partitioning is so simple.Then we will make a partition table (divided into 11 partitions), remove the mysterious veil, and then we can break down each point of the key.Partitioning is to split a table data into sub-collections, that is, to split a data file into multiple data files, but the storage of these files can rely on a filegroup or multiple filegroups, because more than one filegroup can increase

Error message: Server: Message 15135, level 16, status 1, process sp_validatepropertyinputs, row 100 The object is invalid. Extension attributes cannot be used on '. my_score_type.mst_typeid', or the object does not exist. Run the following command (for storing data)Execute sp_addextendedproperty'Ms _ description', -- system type (description)'Category id', -- write Value'User', -- Object Type'', -- Object owner'Table', -- Object Type'My _ score_ty

Label:By using SQL, you can specify aliases (alias) for column names and table names.SQL alias syntax for SQL alias tableSELECT column_name (s) from table_name as alias_name SQL Alias syntax for columnsSELECT column_name as Alias_name from table_name Alias instance: U

The pivot and Unpivot relational operators are the new features provided by SQL Server 2005, so when you use pivot and UNPIVOT for databases that are upgraded to SQL Server 2005, the compatibility level of the database must be set to 90 (you can use sp_ Dbcmptlevel stored procedures to set the compatibility level. Usi