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%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
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% of cheat sheets but are needed for some symbol support.
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\usepackage{MnSymbol}           % Symbols
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% Document Info
\author{blinkdata}
\pdfinfo{
  /Title (entity-framework.pdf)
  /Creator (Cheatography)
  /Author (blinkdata)
  /Subject (Entity Framework Cheat Sheet)
}

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\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
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    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
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\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Entity Framework Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{blinkdata} via \textcolor{DarkBackground}{\uline{cheatography.com/7996/cs/3215/}}}
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\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}blinkdata \\
  \uline{cheatography.com/blinkdata} \\
  \end{tabulary}
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  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 13th May, 2016.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
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  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
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\begin{document}
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% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.


\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Main Classes (1 per entity)}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{public class Student \newline \{ \newline     public Student() \{ \} \newline     public int StudentID \{ get; set; \} \newline     public string StudentName \{ get; set; \} \newline     public DateTime? DateOfBirth \{ get; set; \} \newline     public byte{[}{]}  Photo \{ get; set; \} \newline     public decimal Height \{ get; set; \} \newline     public float Weight \{ get; set; \} \newline          \newline     public int StandardId \{ get; set; \} // foreign key for line below (paired) \newline     public Standard Standard \{ get; set; \}  // 1 per student \newline \} \newline  \newline public class Standard \{ \newline     public Standard() \{ \} \newline     public int StandardId \{ get; set; \} \newline     public string StandardName \{ get; set; \} \newline      \newline     public ICollection\textless{}Student\textgreater{} Students \{ get; set; \}  // many per standard \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{If you dont define the foreign key field name \textless{}class\textgreater{}Id in the Student class, it will be created automatically and called Standard\_StandardId}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{DbContext Class (1 required)}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{public class Context: DbContext  \newline \{ \newline     // SchoolDbConnectionString is the connection string from the config file \newline     public SchoolContext(): \seqsplit{base("name=SchoolDbConnectionString")} \newline     \{ \newline             //Disable initializer - we dont want to lose data EVER \newline             Database.SetInitializer\textless{}SchoolDBContext\textgreater{}(null); \newline      \} \newline              \newline     public DbSet\textless{}Student\textgreater{} Students \{ get; set; \} \newline     public DbSet\textless{}Standard\textgreater{} Standards \{ get; set; \} \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Conventions}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{Primary key is Id or \textless{}class name\textgreater{}Id (or use Data Annotation)} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{Every Entity MUST have a primary key} \tn 
% Row Count 3 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{Foreign keys are created as IList\textless{}T\textgreater{} or ICollection\textless{}T\textgreater{}} \tn 
% Row Count 5 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{x{8.635 cm} x{8.635 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{17.67cm}}{\bf\textcolor{white}{Data Annotations}}  \tn
% Row 0
\SetRowColor{LightBackground}
{[}Key{]} & Make this into a primary key \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
{[}Key{]} {[}Column(Order=1){]} & First part of composite primary key \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
{[}Key{]} {[}Column(Order=2){]} & Second part of composite primary key \tn 
% Row Count 6 (+ 2)
% Row 3
\SetRowColor{white}
{[}TimeStamp{]} public byte{[}{]} RowVersion \{ get; set; \} & Used for concurrency checking. Only works for byte{[}{]}. Autofills \tn 
% Row Count 10 (+ 4)
% Row 4
\SetRowColor{LightBackground}
{[}ConcurrencyCheck{]} & Use as a concurrency check. Any type. No autofill \tn 
% Row Count 13 (+ 3)
% Row 5
\SetRowColor{white}
{[}Required{]} & Required value.  Forces NOT NULL \tn 
% Row Count 15 (+ 2)
% Row 6
\SetRowColor{LightBackground}
{[}MaxLength(50){]} & Maximum of 50 characters \tn 
% Row Count 17 (+ 2)
% Row 7
\SetRowColor{white}
{[}MinLength(2){]} & Minimum of 2 characters \tn 
% Row Count 19 (+ 2)
% Row 8
\SetRowColor{LightBackground}
{[}MaxLength(50),MinLength(2){]} & Min and Max length combined \tn 
% Row Count 21 (+ 2)
% Row 9
\SetRowColor{white}
{[}StringLength(50){]} & Make nvarchar(50) instead of nvarchar(max) \tn 
% Row Count 24 (+ 3)
% Row 10
\SetRowColor{LightBackground}
{[}Column("Name"){]} & Use this as field name in the DB instead of the property name \tn 
% Row Count 28 (+ 4)
% Row 11
\SetRowColor{white}
{[}Column("Name", Typename="varchar"){]} & Set the fieldname and the data type \tn 
% Row Count 30 (+ 2)
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{x{8.635 cm} x{8.635 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{17.67cm}}{\bf\textcolor{white}{Data Annotations (cont)}}  \tn
% Row 12
\SetRowColor{LightBackground}
{[}NotMapped{]} & Dont create a field in the database (unbound data) \tn 
% Row Count 3 (+ 3)
% Row 13
\SetRowColor{white}
{[}ForeignKey("SpecificIdField"){]} & Use the specified id field to hold the foreign key value \tn 
% Row Count 6 (+ 3)
% Row 14
\SetRowColor{LightBackground}
{[}Index{]} & Create a non clustered index on thsi field \tn 
% Row Count 9 (+ 3)
% Row 15
\SetRowColor{white}
{[}Index( "INDEX\_REGNUM", IsClustered=true, IsUnique=true ){]} & Create a clustered, unique index with the given name (instead of IX\_propertyname) \tn 
% Row Count 14 (+ 5)
% Row 16
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{17.67cm}}{} \tn 
% Row Count 14 (+ 0)
% Row 17
\SetRowColor{white}
{[}Table("StudentMaster"){]} & Use this as the table name instead of the class name \tn 
% Row Count 17 (+ 3)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{17.67cm}}{The "Table" annotation goes just before the public class line.  All other annotations go before the properties themselves}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{x{8.635 cm} x{8.635 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{17.67cm}}{\bf\textcolor{white}{DbEntityEntry}}  \tn
% Row 0
\SetRowColor{LightBackground}
var entry = \seqsplit{context.Entry(student)} & Get a DbEntityEntry for the current student \tn 
% Row Count 3 (+ 3)
% Row 1
\SetRowColor{white}
entry.State & Return Modified, Deleted, Added, Unchanged or Detached \tn 
% Row Count 6 (+ 3)
% Row 2
\SetRowColor{LightBackground}
entry.OriginalValues{[}"age"{]} & The original (unchanged) value \tn 
% Row Count 8 (+ 2)
% Row 3
\SetRowColor{white}
entry.CurrentValues{[}"age"{]} & The current value \tn 
% Row Count 10 (+ 2)
% Row 4
\SetRowColor{LightBackground}
\seqsplit{context.Entry(student).State} = \seqsplit{System.Data.Entity.EntityState.Modified;} & Force to a modified state (even if it hasnt been)  Needed for disconnected entities \tn 
% Row Count 15 (+ 5)
% Row 5
\SetRowColor{white}
entry.Reload(); & Forces the data to be reloaded from the database (state will become UnChanged)  All changes will be lost \tn 
% Row Count 21 (+ 6)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{17.67cm}}{Note : The context will have been created with:   \newline using (var context = new SchoolDBEntities()) \{ \}}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Add Entity (in disconnected state)}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{// create new Student entity object in disconnected scenario (out of the scope of DbContext) \newline var newStudent = new Student(); \newline  \newline //set student name \newline newStudent.StudentName = "Bill"; \newline  \newline //create DBContext object \newline using (var dbCtx = new SchoolDBEntities()) \{ \newline     //Add Student object into Students DBset \newline     \seqsplit{dbCtx.Students.Add(newStudent);} \newline                  \newline     // call SaveChanges method to save student into database \newline     dbCtx.SaveChanges(); \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Update Entity (in disconnected state)}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{//1. Get student from DB \newline using (var ctx = new SchoolDBEntities()) \newline \{ \newline     stud = ctx.Students.Where(s =\textgreater{} s.StudentName == "New Student1").FirstOrDefault\textless{}Student\textgreater{}(); \newline \} \newline  \newline //2. change student name in disconnected mode (out of ctx scope) \newline if (stud != null) \newline \{ \newline     stud.StudentName = "Updated Student1"; \newline \} \newline  \newline //save modified entity using new Context \newline using (var dbCtx = new SchoolDBEntities()) \newline \{ \newline     //3. Mark entity as modified \newline     dbCtx.Entry(stud).State = \seqsplit{System.Data.Entity.EntityState.Modified;}      \newline          \newline     //4. call SaveChanges \newline     dbCtx.SaveChanges(); \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Delete Entity (in disconnected state)}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{//1. Get student from DB \newline using (var ctx = new SchoolDBEntities()) \newline \{ \newline     studentToDelete = ctx.Students.Where(s =\textgreater{} s.StudentName == "Student1").FirstOrDefault\textless{}Student\textgreater{}(); \newline \} \newline  \newline //Create new context for disconnected scenario \newline using (var newContext = new SchoolDBEntities()) \newline \{ \newline     \seqsplit{newContext.Entry(studentToDelete).State} = \seqsplit{System.Data.Entity.EntityState.Deleted;}     \newline  \newline     \seqsplit{newContext.SaveChanges();} \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Update Entity Graph using DbContext}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{17.67cm}}{TBA !!! \newline % Row Count 1 (+ 1)
Complex - needs more research at this stage% Row Count 2 (+ 1)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Raw SQL}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{using (var ctx = new SchoolDBEntities()) \newline \{ \newline     //Update command \newline     int noOfRowUpdated = \seqsplit{ctx.Database.ExecuteSqlCommand("Update} student  \newline             set studentname ='changed student by command' where studentid=1"); \newline     //Insert command \newline     int noOfRowInserted = \seqsplit{ctx.Database.ExecuteSqlCommand("insert} into student(studentname)  \newline             values('New Student')"); \newline     //Delete command \newline     int noOfRowDeleted = \seqsplit{ctx.Database.ExecuteSqlCommand("delete} from student  \newline             where studentid=1"); \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Convert DbContext to ObjectContext}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{using (var ctx = new SchoolDBEntities()) \{ \newline     var objectContext = (ctx as \seqsplit{System.Data.Entity.Infrastructure.IObjectContextAdapter).ObjectContext;} \newline     //use objectContext here.. \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Queries}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{// Get a record by its Primary key value - return null if no record found \newline using (var ctx = new SchoolDBEntities()) \newline \{     \newline     var student = ctx.Students.Find(\_id); \newline \} \newline  \newline // Get the first (TOP 1) record - return null if no record found \newline using (var ctx = new SchoolDBEntities()) \newline \{     \newline     var student = (from s in ctx.Students \newline                 where s.StudentName == "Student1" \newline                 select s).FirstOrDefault\textless{}Student\textgreater{}(); \newline \} \newline  \newline // Get a List of records that match the criteria \newline using (var ctx = new SchoolDBEntities()) \newline \{     \newline     var studentList = (from s in ctx.Students \newline         where s.StudentName == "Student1" \newline         orderby s.StudentName ascending \newline         select s).ToList\textless{}Student\textgreater{}(); \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{17.67cm}}{\bf\textcolor{white}{Other Notes}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{17.67cm}}{How to set default values} \tn 
\mymulticolumn{1}{x{17.67cm}}{\hspace*{6 px}\rule{2px}{6px}\hspace*{6 px}Create a new partial class (don't edit the autogenerated one) and set the default values in the constructor of the new class.} \tn 
% Row Count 4 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}



\end{document}