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SQL Switch/Case in where clause

I tried searching around but couldn't find anything that would help me out.

I'm trying to do this in SQL:

declare @locationType varchar(50);
declare @locationID int;

SELECT column1, column2
FROM viewWhatever
WHERE
CASE @locationType
    WHEN 'location' THEN account_location = @locationID
    WHEN 'area' THEN xxx_location_area = @locationID
    WHEN 'division' THEN xxx_location_division = @locationID

I know that I shouldn't have to put '= @locationID' at the end of each one but I can't get the syntax even close to being correct. SQL keeps complaining about my '=' on the first WHEN line...

Help!

Why can't variables be declared in a switch statement?

I've always wondered this - why can't you declare variables after a case label in a switch statement? In C++ you can declare variables pretty much anywhere (and declaring them close to first use is obviously a good thing) but the following still won't work:

switch (val)  
{  
case VAL:  
  // This won't work
  int newVal = 42;  
  break;
case ANOTHER_VAL:  
  ...
  break;
}

The above gives me the following error (MSC):

initialization of 'newVal' is skipped by 'case' label

This seems to be a limitation in other languages too. Why is this such a problem?

Ruby - Case statement with multiple values in each 'when' block

The best way I can describe what I'm looking for is to show you the failed code I've tried thus far:

case car
  when ['honda', 'acura'].include?(car)
    # code
  when 'toyota' || 'lexus'
    # code
end

I've got about 4 or 5 different when situations that should be triggered by approximately 50 different possible values of car. Is there a way to do this with case blocks or should I try a massive if block?

Replacements for switch/case statement in Python?

I want to write a function in Python that returns different fixed values based on the value of an input index.

In other languages I would use a switch or case statement, but Python does not appear to have a switch statement. What are the recommended Python solutions in this scenario?

How can I write a switch statement in Ruby?

How do I write a switch statement in Ruby?

Why can't I switch on a String?

Why can't I switch on a String?

Is this functionality going to be put into a later Java version?

Can someone explain why I can't do this, as in, the technical way Java's switch statement works?

Is 'switch' faster than 'if'?

Is a switch statement actually faster than an if statement?

I ran the code below on Visual Studio 2010's x64 C++ compiler with the /Ox flag:

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

#define MAX_COUNT (1 << 29)
size_t counter = 0;

size_t testSwitch()
{
    clock_t start = clock();
    size_t i;
    for (i = 0; i < MAX_COUNT; i++)
    {
        switch (counter % 4 + 1)
        {
            case 1: counter += 4; break;
            case 2: counter += 3; break;
            case 3: counter += 2; break;
            case 4: counter += 1; break;
        }
    }
    return 1000 * (clock() - start) / CLOCKS_PER_SEC;
}

size_t testIf()
{
    clock_t start = clock();
    size_t i;
    for (i = 0; i < MAX_COUNT; i++)
    {
        const size_t c = counter % 4 + 1;
        if (c == 1) { counter += 4; }
        else if (c == 2) { counter += 3; }
        else if (c == 3) { counter += 2; }
        else if (c == 4) { counter += 1; }
    }
    return 1000 * (clock() - start) / CLOCKS_PER_SEC;
}

int main()
{
    printf("Starting...\n");
    printf("Switch statement: %u ms\n", testSwitch());
    printf("If     statement: %u ms\n", testIf());
}

and got these results:

Switch statement: 5261 ms
If statement: 5196 ms

From what I've learned, switch statements apparently use jump tables to optimize the branching.

Questions:

1. What would a basic jump table look like, in x86 or x64?

2. Is this code using a jump table?

3. Why is there no performance difference in this example? Is there any situation in which there is a significant performance difference?

Disassembly of the code:

testIf:

13FE81B10 sub  rsp,48h 
13FE81B14 call qword ptr [__imp_clock (13FE81128h)] 
13FE81B1A mov  dword ptr [start],eax 
13FE81B1E mov  qword ptr [i],0 
13FE81B27 jmp  testIf+26h (13FE81B36h) 
13FE81B29 mov  rax,qword ptr [i] 
13FE81B2E inc  rax  
13FE81B31 mov  qword ptr [i],rax 
13FE81B36 cmp  qword ptr [i],20000000h 
13FE81B3F jae  testIf+0C3h (13FE81BD3h) 
13FE81B45 xor  edx,edx 
13FE81B47 mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81B4E mov  ecx,4 
13FE81B53 div  rax,rcx 
13FE81B56 mov  rax,rdx 
13FE81B59 inc  rax  
13FE81B5C mov  qword ptr [c],rax 
13FE81B61 cmp  qword ptr [c],1 
13FE81B67 jne  testIf+6Dh (13FE81B7Dh) 
13FE81B69 mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81B70 add  rax,4 
13FE81B74 mov  qword ptr [counter (13FE835D0h)],rax 
13FE81B7B jmp  testIf+0BEh (13FE81BCEh) 
13FE81B7D cmp  qword ptr [c],2 
13FE81B83 jne  testIf+89h (13FE81B99h) 
13FE81B85 mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81B8C add  rax,3 
13FE81B90 mov  qword ptr [counter (13FE835D0h)],rax 
13FE81B97 jmp  testIf+0BEh (13FE81BCEh) 
13FE81B99 cmp  qword ptr [c],3 
13FE81B9F jne  testIf+0A5h (13FE81BB5h) 
13FE81BA1 mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81BA8 add  rax,2 
13FE81BAC mov  qword ptr [counter (13FE835D0h)],rax 
13FE81BB3 jmp  testIf+0BEh (13FE81BCEh) 
13FE81BB5 cmp  qword ptr [c],4 
13FE81BBB jne  testIf+0BEh (13FE81BCEh) 
13FE81BBD mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81BC4 inc  rax  
13FE81BC7 mov  qword ptr [counter (13FE835D0h)],rax 
13FE81BCE jmp  testIf+19h (13FE81B29h) 
13FE81BD3 call qword ptr [__imp_clock (13FE81128h)] 
13FE81BD9 sub  eax,dword ptr [start] 
13FE81BDD imul eax,eax,3E8h 
13FE81BE3 cdq       
13FE81BE4 mov  ecx,3E8h 
13FE81BE9 idiv eax,ecx 
13FE81BEB cdqe      
13FE81BED add  rsp,48h 
13FE81BF1 ret       

testSwitch:

13FE81C00 sub  rsp,48h 
13FE81C04 call qword ptr [__imp_clock (13FE81128h)] 
13FE81C0A mov  dword ptr [start],eax 
13FE81C0E mov  qword ptr [i],0 
13FE81C17 jmp  testSwitch+26h (13FE81C26h) 
13FE81C19 mov  rax,qword ptr [i] 
13FE81C1E inc  rax  
13FE81C21 mov  qword ptr [i],rax 
13FE81C26 cmp  qword ptr [i],20000000h 
13FE81C2F jae  testSwitch+0C5h (13FE81CC5h) 
13FE81C35 xor  edx,edx 
13FE81C37 mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81C3E mov  ecx,4 
13FE81C43 div  rax,rcx 
13FE81C46 mov  rax,rdx 
13FE81C49 inc  rax  
13FE81C4C mov  qword ptr [rsp+30h],rax 
13FE81C51 cmp  qword ptr [rsp+30h],1 
13FE81C57 je   testSwitch+73h (13FE81C73h) 
13FE81C59 cmp  qword ptr [rsp+30h],2 
13FE81C5F je   testSwitch+87h (13FE81C87h) 
13FE81C61 cmp  qword ptr [rsp+30h],3 
13FE81C67 je   testSwitch+9Bh (13FE81C9Bh) 
13FE81C69 cmp  qword ptr [rsp+30h],4 
13FE81C6F je   testSwitch+0AFh (13FE81CAFh) 
13FE81C71 jmp  testSwitch+0C0h (13FE81CC0h) 
13FE81C73 mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81C7A add  rax,4 
13FE81C7E mov  qword ptr [counter (13FE835D0h)],rax 
13FE81C85 jmp  testSwitch+0C0h (13FE81CC0h) 
13FE81C87 mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81C8E add  rax,3 
13FE81C92 mov  qword ptr [counter (13FE835D0h)],rax 
13FE81C99 jmp  testSwitch+0C0h (13FE81CC0h) 
13FE81C9B mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81CA2 add  rax,2 
13FE81CA6 mov  qword ptr [counter (13FE835D0h)],rax 
13FE81CAD jmp  testSwitch+0C0h (13FE81CC0h) 
13FE81CAF mov  rax,qword ptr [counter (13FE835D0h)] 
13FE81CB6 inc  rax  
13FE81CB9 mov  qword ptr [counter (13FE835D0h)],rax 
13FE81CC0 jmp  testSwitch+19h (13FE81C19h) 
13FE81CC5 call qword ptr [__imp_clock (13FE81128h)] 
13FE81CCB sub  eax,dword ptr [start] 
13FE81CCF imul eax,eax,3E8h 
13FE81CD5 cdq       
13FE81CD6 mov  ecx,3E8h 
13FE81CDB idiv eax,ecx 
13FE81CDD cdqe      
13FE81CDF add  rsp,48h 
13FE81CE3 ret       

Update:

Interesting results here and here. Not sure why one is faster and one is slower, though.

Why doesn't Python have a switch statement? [closed]

What is the reason Python doesn't have switch statement?

Case in protected switch [duplicate]

Possible Duplicate:
When converting a project to use ARC what does “switch case is in protected scope” mean?

Got the following xcode: But when i try to put something in case 1 (or empty) it's giving me an error?

Weird problem because i dont know what a protected switch is and how i should fix it. Does anyone has a solution or clue to fix this? Weird..

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    UIViewController *controller;

    switch(indexPath.row) {
        case 0:
            NSLog(@"0");

            //create instance of EKEventStore
            EKEventStore *eventStore = [[EKEventStore alloc] init];

            //creating instance of EKEvent
            EKEvent *event  = [EKEvent eventWithEventStore:eventStore];

            //setting the appropriate properties of the new event
            event.title     = @"Woow";

            //event.startDate = [[NSDate alloc] init];



            NSDateComponents *myDate2 = [[NSDateComponents alloc] init];
            [myDate2 setDay:13];
            [myDate2 setMonth:12];
            [myDate2 setYear:2011];
            [myDate2 setHour:00];
            [myDate2 setMinute:34];

            event.startDate = [[NSCalendar currentCalendar] dateFromComponents:myDate2];

            event.endDate   = [[NSDate alloc] initWithTimeInterval:3600 sinceDate:event.startDate];
            event.location = @"game2";
            event.notes = @" game";

            event.alarms = [NSArray arrayWithObject:[EKAlarm alarmWithAbsoluteDate:event.startDate]];

            [event setCalendar:[eventStore defaultCalendarForNewEvents]];
            NSError *error;
            [eventStore saveEvent:event span:EKSpanThisEvent error:&error];

            break;

        case 1:
            NSLog(@"1");    






            break;






    }

    {



        self.EKController.title = [self.EKList objectAtIndex:[indexPath row]];






    }

}


@end

But an error:

How can I increment a variable without exceeding a maximum value?

I am working on a simple video game program for school and I have created a method where the player gets 15 health points if that method is called. I have to keep the health at a max of 100 and with my limited programming ability at this point I am doing something like this.

public void getHealed(){
    if(health <= 85)
        health += 15;
    else if(health == 86)
        health += 14;
    else if(health == 87)
    health += 13; 
}// this would continue so that I would never go over 100

I understand my syntax about isnt perfect but my question is, what may be a better way to do it, because I also have to do a similar thing with the damage points and not go below 0.

Declaring variables inside a switch statement [duplicate]

I saw a few answers to this issue, and I get it — you can't declare and assign variables inside a switch. But I'm wondering if the following is correct at throwing an error saying

error: expected expression before 'int'

Code:

switch (i) {
    case 0:
        int j = 1;
        break;
}

Why would putting a call to NSLog() before it result in no errors?

switch (i) {
    case 0:
        NSLog(@"wtf");
        int j = 1;
        break;
}

Using Case/Switch and GetType to determine the object [duplicate]

Possible Duplicate:
C# - Is there a better alternative than this to ‘switch on type’?

If you want to switch on a type of object, what is the best way to do this?

Code snippet

private int GetNodeType(NodeDTO node)
{
    switch (node.GetType())
    { 
        case typeof(CasusNodeDTO):
            return 1;
        case typeof(BucketNodeDTO):
            return 3;
        case typeof(BranchNodeDTO):
            return 0;
        case typeof(LeafNodeDTO):
            return 2;
        default:
            return -1;
    }
}

I know this doesn't work that way, but I was wondering how you could solve this. Is an if/else statement appropriate in this case?

Or do you use the switch and add .ToString() to the type?

Switch statement for string matching in JavaScript

How do I write a swtich for the following conditional?

If the url contains "foo", then settings.base_url is "bar".

The following is achieving the effect required but I've a feeling this would be more manageable in a switch:

var doc_location = document.location.href;
var url_strip = new RegExp("http:\/\/.*\/");
var base_url = url_strip.exec(doc_location)
var base_url_string = base_url[0];

//BASE URL CASES

// LOCAL
if (base_url_string.indexOf('xxx.local') > -1) {
    settings = {
        "base_url" : "http://xxx.local/"
    };
}

// DEV
if (base_url_string.indexOf('xxx.dev.yyy.com') > -1) {
    settings = {
        "base_url" : "http://xxx.dev.yyy.com/xxx/"
    };
}

How to use a switch case 'or' in PHP?

Is there any way of using an 'OR' operator or equivalent in a php switch? For example, something like this:

switch ($value) {

case 1 || 2:
echo 'the value is either 1 or 2';
break;

}

Switch statement: must default be the last case?

Consider the following switch statement:

switch( value )
{
  case 1:
    return 1;
  default:
    value++;
    // fall-through
  case 2:
    return value * 2;
}

This code compiles, but is it valid (= defined behavior) for C90/C99? I have never seen code where the default case is not the last case.

EDIT:
As Jon Cage and KillianDS write: this is really ugly and confusing code and I am well aware of it. I am just interested in the general syntax (is it defined?) and the expected output.