تاریخچهای از روشهای مختلف صفحه بندی اطلاعات در SQL Server در این مقاله بحث شده به همراه بررسی کارآیی آنها:
Comparing performance for different SQL Server paging methods
تاریخچهای از روشهای مختلف صفحه بندی اطلاعات در SQL Server در این مقاله بحث شده به همراه بررسی کارآیی آنها:
Comparing performance for different SQL Server paging methods
SELECT top 1 * FROM (EXEC MyProc) AS TEMP
context.Products.FromSqlRaw("[dbo].[Ten Most Expensive Products]").AsEnumerable().FirstOrDefault();
CREATE FUNCTION dbo.checkPerson(@data XML) RETURNS BIT WITH SCHEMABINDING AS BEGIN RETURN @data.exist('/people/person') END GO CREATE TABLE tblXML ( id INT PRIMARY KEY, doc XML CHECK(dbo.checkPerson(doc)=1) ) GO
INSERT INTO tblXML (id, doc) VALUES ( 1, '<people><person name="Vahid"/></people>' ) INSERT INTO tblXML (id, doc) VALUES ( 2, '<people><emp name="Vahid"/></people>' )
The INSERT statement conflicted with the CHECK constraint "CK__tblXML__doc__060DEAE8". The conflict occurred in database "testdb", table "dbo.tblXML", column 'doc'. The statement has been terminated.
CREATE TABLE xml_tab ( id INT IDENTITY PRIMARY KEY, xml_col XML )
INSERT INTO xml_tab VALUES ('<people><person name="Vahid"/></people>') INSERT INTO xml_tab VALUES ('<people><person name="Farid"/></people>')
SELECT id, xml_col.value('(/people/person/@name)[1]', 'varchar(50)') AS name FROM xml_tab
CREATE FUNCTION getIdValue(@doc XML) RETURNS int WITH SCHEMABINDING AS BEGIN RETURN @doc.value('/*[1]/@Id', 'int') END
CREATE TABLE docs_tab ( id INT PRIMARY KEY, doc XML, CONSTRAINT id_chk CHECK(dbo.getIdValue(doc)=id) )
INSERT INTO docs_tab (id, doc) VALUES ( 1, '<Invoice Id="1"/>' ) INSERT INTO docs_tab (id, doc) VALUES ( 2, '<Invoice Id="1"/>' )
The INSERT statement conflicted with the CHECK constraint "id_chk". The conflict occurred in database "testdb", table "dbo.docs_tab". The statement has been terminated.
CREATE TABLE Invoices ( doc XML, id AS dbo.getIdValue(doc) PERSISTED PRIMARY KEY )
INSERT INTO Invoices VALUES ( '<Invoice Id="1"/>' ) INSERT INTO Invoices VALUES ( '<Invoice Id="1"/>' )
Violation of PRIMARY KEY constraint 'PK__Invoices__3213E83F145C0A3F'. Cannot insert duplicate key in object 'dbo.Invoices'. The duplicate key value is (1). The statement has been terminated.
DECLARE @doc XML SET @doc = '<foo bar="baz" />' SELECT @doc.query('/foo/@bar')
XQuery [query()]: Attribute may not appear outside of an element
DECLARE @doc XML SET @doc = '<foo bar="baz" />' SELECT @doc.query('data(/foo/@bar)')
DECLARE @x XML SET @x = '<x>hello<y>world</y></x><x>again</x>' SELECT @x.query('data(/*)')
DECLARE @x XML SET @x = '<x>hello<y>world</y></x><x>again</x>' SELECT @x.query('string(/*)')
XQuery [query()]: 'string()' requires a singleton (or empty sequence), found operand of type 'element(*,xdt:untyped) *'
SELECT @x.query('string(/*[1])')
SELECT @x.query('string(/)')
DECLARE @x XML = '<age>12</age>' SELECT @x.query('string(/age[1])')
CREATE XML SCHEMA COLLECTION root_el AS '<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="urn:geo"> <xs:element name="Root" type="xs:string" /> </xs:schema> ' GO
DECLARE @xmlDoc XML SET @xmlDoc = '<g:Root xmlns:g="urn:geo">datadata...</g:Root>' SELECT @xmlDoc.query(' declare namespace g="urn:geo"; /g:Root/text() ')
DECLARE @xmlDoc XML(root_el) SET @xmlDoc = '<g:Root xmlns:g="urn:geo">datadata...</g:Root>' SELECT @xmlDoc.query(' declare namespace g="urn:geo"; /g:Root[1]/text() ')
XQuery [query()]: 'text()' is not supported on simple typed or 'http://www.w3.org/2001/XMLSchema#anyType' elements, found 'element(g{urn:geo}:Root,xs:string) *'.
DECLARE @xmlDoc XML(root_el) SET @xmlDoc = '<g:Root xmlns:g="urn:geo">datadata...</g:Root>' SELECT @xmlDoc.query(' declare namespace g="urn:geo"; data(/g:Root[1]) ')
data(/age/text())
var test1 = context.Blogs .Where(blog => String.Compare(blog.Url, "A", StringComparison.Ordinal) > 0) .ToList(); // SELECT [blog].[BlogId], [blog].[Url] // FROM [Blogs] AS [blog]
var test2 = context.Blogs .Where(blog => String.Compare(blog.Url, "B") > 0) .ToList(); // SELECT [blog].[BlogId], [blog].[Url] // FROM [Blogs] AS [blog] // WHERE [blog].[Url] > N'B'
var test3 = context.Blogs .Where(blog => blog.Url.Equals("C", StringComparison.OrdinalIgnoreCase)) .ToList(); // SELECT [blog].[BlogId], [blog].[Url] // FROM [Blogs] AS [blog]
var test3_1 = context.Blogs .Where(blog => blog.Url.Equals("C_1")) .ToList(); // SELECT [blog].[BlogId], [blog].[Url] // FROM [Blogs] AS [blog] // WHERE [blog].[Url] = N'C_1'
var test4 = context.Blogs .Where(blog => blog.Url.StartsWith("D")) .ToList(); // SELECT [blog].[BlogId], [blog].[Url] // FROM [Blogs] AS [blog] // WHERE [blog].[Url] LIKE N'D' + N'%' AND (LEFT([blog].[Url], LEN(N'D')) = N'D')
var test5 = context.Blogs .Where(blog => EF.Functions.Like(blog.Url, "S_i%")) .ToList(); // SELECT [blog].[BlogId], [blog].[Url] // FROM [Blogs] AS [blog] // WHERE [blog].[Url] LIKE N'S_i%'
var test6 = context.Blogs .Where(blog => blog.Url.ToUpper() == "E") .ToList(); // SELECT [blog].[BlogId], [blog].[Url] // FROM [Blogs] AS [blog] // WHERE UPPER([blog].[Url]) = N'E'
var test7 = context.Blogs .Where(blog => blog.Url.ToUpperInvariant() == "F") .ToList(); // SELECT [blog].[BlogId], [blog].[Url] // FROM [Blogs] AS [blog]
DRIVER={MySQL ODBC 5.1 Driver}; SERVER=localhost; DATABASE=testdb; USER=root; PASSWORD=mypass; OPTION=3;PORT=3306; CharSet=UTF8;
EXECUTE('insert into testdb.testtable(f1,f1) values(1,''data'')') at mysql
Server 'mysql' is not configured for RPC.
SELECT * FROM OPENQUERY(mysql, 'SELECT * FROM testdb.testtable')
SELECT * INTO MyDb.dbo.testtable FROM openquery(MYSQL, 'SELECT * FROM testdb.testtable')