entity framework - Why does code first/EF use 'nvarchar(4000)' for strings in the raw SQL command? -


essentially have table zip codes in it. zipcode field defined 'char(5)'. i'm using code first, i've put these attributes on zipcode property:

[key, column( order = 0, typename = "nchar"), stringlength(5)] public string zipcode { get; set; }

now if query against in ef:

var zc = db.zipcodes.firstordefault(zip => zip.zipcode == "12345");

the generated sql uses nvarchar(4000) inject parameters. huh? because "12345" technically string of unknown length? shouldn't ef smart enough use proper "nchar(5)" when querying table?

i ask because nvarchar(4000) query takes half second whereas properly-scoped query faster (and less reads).

any assistance/advice appreciated.

this take advantage of auto parameterization. following article explains general concept why nvarchar(4000) used.

http://msdn.microsoft.com/en-us/magazine/ee236412.aspx


Comments

Post a Comment

Popular posts from this blog

c# - SharpSVN - How to get the previous revision? -

i trying find efficient way previous revision of file text comparison using sharpsvn. using (svnclient c = new svnclient()) { c.authentication.defaultcredentials = new networkcredential( configurationmanager.appsettings.get("svnserviceusername") , configurationmanager.appsettings.get("svnservicepassword") , configurationmanager.appsettings.get("svnservicedomain") ); c.authentication.sslservertrusthandlers += new eventhandler<svnsslservertrusteventargs>(authentication_sslservertrusthandlers); collection<svnfileversioneventargs> fileversioncollection = new collection<svnfileversioneventargs>(); svnrevisionrange range = new svnrevisionrange(0, this.hooks.revision); svnfileversionsargs args = new svnfileversionsargs(); args.retrieveproperties = true; args.range = range; foreach (svnchangeitem item in log.changedpaths) { string path = this.repositorypath + it...
Read more

c++ - Is it possible to compile a VST on linux? -

for class project i'm attempting write vst plugin backed cuda. current cuda workflow on linux box, i'd prefer compile , link there. according wikipedia , should possible (i couldn't find steinberg documentation relevant linux) can't find makefile or instructions on how build if aren't using xcode or visual studio. i'm vst 3 sdk doesn't support linux. when try compile plugin under linux, error: ./base/source/fatomic.cpp:39:30: fatal error: libkern/osatomic.h: no such file or directory this issue caused following code in "vst3 sdk/base/source/fatomic.cpp" #if mac #include <libkern/osatomic.h> #if mac_os_x_version_min_required > mac_os_x_version_10_4 #define native_atomic_type (volatile int32_t*) #else #define native_atomic_type (int32_t*) #endif #elif windows #include <windows.h> #endif but hope compiling under linux work vst sdk 2.4. reading. jvstwrapper seems run on lin...
Read more

url - Querystring manipulation of email Address in PHP -

i using third party application (email2http) send me emailid, body , message. unable retrieve email id due name appended on , enclosed < , >. here querystring getting. test.php?from=ajay+reddy &subject=cx&body=somebody when print variable in php returns name , not email id. $from = $_get['from']; echo $from; //output ajay reddy please suggest me how can emailid also. i dont want use post method due testing , debugging. it's working fine. forgot use htmlentities() in debugging.
Read more