database - SQL IS NULL logic error -



database - SQL IS NULL logic error -

i'm new forum i'm not sure if it's post twice same questions seems lastly question sort of died out , kind of have new question, here is

i wanted programme if combo box empty, mean select (or imagine ignore where clause start out with). reply found throughout net utilize param = @param or @param null. however, when , want display data, shows column row names (meaning got right table) no data. i'm not sure why, read method sort of if statement. here's code simplified jut problem

da.selectcommand = new oledbcommand("select * testquery customername = @customername or @customername null)", cs); da.selectcommand.parameters.add("@customername", oledbtype.varchar).value = combo_customerview.text.tostring();

da = info adapter. i'm using visual studio 2010 , ado.net oledb (access). works when have info on client when theres none, problem described above. sorta help helpful... thanks

sql database visual-studio-2010 ms-access ado.net

Comments

Post a Comment

Popular posts from this blog

java - How to pass parameters between Request-Scoped Controllers? -

java - How to pass parameters between Request-Scoped Controllers? - i have simple jsf-page , want pass parameter page1 page2. every page has own controller in request scope. the 2 controllers this: controller1: @component("requestcontroller1") @scope("request") public class requestcontroller1 { private list<product> products; private product selectedproduct; @postconstruct public void init() { //load products db } public void setproducts(list<product> products) { this.products = products; } public list<product> getproducts() { homecoming products; } public void setselectedproduct(product selectedproduct) { this.selectedproduct = selectedproduct; } public product getselectedproduct() { homecoming selectedproduct; } controller2: @component("requestcontroller2") @scope("request") public class requestcontroller2 { private long selectedproductid; @postconstruct public void init() ...
Read more

string - what is the difference between "some" == "some\0" and strcmp("some","some\0") in c++? -

string - what is the difference between "some" == "some\0" and strcmp("some","some\0") in c++? - what difference between "some" == "some\0" , strcmp("some","some\0") in c++? why if("some" == "some\0") returns false , if(!strcmp("some","some\0")) returns true ? see next diagram. shows 2 strings in memory, content in box, beside box you'll see address of each one. when you're doing if("some" == "some\0") comparing addresses. translated if (0xdeadbeef == 0x0badcafe) false. when utilize strcmp , compare content of each box until reach \0 in each of them. that's why sec test returns true. if alter first test if("some" == "some") compiler may potentially see same strings , store them once. means test transform if (0x0badcafe == 0x0badcafe) true. c++ string comparison
Read more

actionscript 3 - Flex: moving a point with rotation doesnt change the point XY? -

actionscript 3 - Flex: moving a point with rotation doesnt change the point XY? - i have follow issue : i have point setted @ border on component, changed transform point center of component in order match component rotation. the of import part when seek point xy after rotation - remains same before rotation. how xy, after rotation ( changeing point.rotation property specific degrees of rotaion ) if want point after rotation, cos(r) * x, sin(r) * y easiest way. if want point after transformations, should able utilize displayobject.transform.transformpoint(x, y) . there's displayobject.localtoglobal . in case phone call localtoglobal(x, y) , localtoglobal(0, 0) , calculate difference. see transform livedocs , displayobject livedocs flex actionscript-3
Read more