iPhone：SQLite数据库打开不起作用

Question

I am new to iOS sqlite. I am working on xcode 4.2. Here is my code:

.h file

#import <UIKit/UIKit.h>
#import </usr/include/sqlite3.h>

@interface RpTestViewController : UIViewController {
    sqlite3 *db;
    NSString *dbPath;
}

@end

.m file

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.


    NSString *docsDir;
    NSArray *dirPaths;

    dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    docsDir = [dirPaths objectAtIndex:0];

    dbPath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent: @"test.db"]];

    NSFileManager *fileMgr = [NSFileManager defaultManager];

    if([fileMgr fileExistsAtPath: dbPath] == NO)
    {
        const char *_dbPath = [dbPath UTF8String];
        if(sqlite3_open(_dbPath, &db)  == SQLITE_OK)
        {
            char *err;
            const char *sql = "create table if not exists test_group (groupID integer primary key autoincrement, name, name_arr)";
            if(sqlite3_exec(db, sql, NULL, NULL, &err) != SQLITE_OK)
            {
                NSLog(@"failed to create table");
            }
            else
            {
                NSLog(@"ok...");
            }
        }
    }
}

But, i got following error when I try to run:

Ld /Users/remoteprogrammer/Library/Developer/Xcode/DerivedData/fitest-bjghexnpsekbougtezdjshnnugzl/Build/Products/Debug-iphonesimulator/fitest.app/fitest normal i386
    cd /MRK/iPhone/test/fitest
    setenv MACOSX_DEPLOYMENT_TARGET 10.6
    setenv PATH "/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/clang -arch i386 -isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk -L/Users/remoteprogrammer/Library/Developer/Xcode/DerivedData/fitest-bjghexnpsekbougtezdjshnnugzl/Build/Products/Debug-iphonesimulator -F/Users/remoteprogrammer/Library/Developer/Xcode/DerivedData/fitest-bjghexnpsekbougtezdjshnnugzl/Build/Products/Debug-iphonesimulator -filelist /Users/remoteprogrammer/Library/Developer/Xcode/DerivedData/fitest-bjghexnpsekbougtezdjshnnugzl/Build/Intermediates/fitest.build/Debug-iphonesimulator/fitest.build/Objects-normal/i386/fitest.LinkFileList -mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -fobjc-arc -Xlinker -no_implicit_dylibs -D__IPHONE_OS_VERSION_MIN_REQUIRED=50000 -framework UIKit -framework Foundation -framework CoreGraphics -o /Users/remoteprogrammer/Library/Developer/Xcode/DerivedData/fitest-bjghexnpsekbougtezdjshnnugzl/Build/Products/Debug-iphonesimulator/fitest.app/fitest

Undefined symbols for architecture i386:
  "_sqlite3_open", referenced from:
      -[RpTestViewController viewDidLoad] in RpTestViewController.o
  "_sqlite3_exec", referenced from:
      -[RpTestViewController viewDidLoad] in RpTestViewController.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

How to resolve this problem.

Answer 1

All you have to add libsqlite3.dylib library to your project. And you can do it by going on Build Pahse in your Target Settings, then in "Link Binary With Libraries" you have to add the desired library and It will work.

Answer 2

Undefined symbols for architecture i386:

For this type of error you must check if you have added all the required framework or header files or not.

you must add libsqlite3.dylib to run your project.

Thanks

Answer 3

• Select the bundle of you project (Project Name folder at the top of the Project navigator having blue icon)
• Go to "Build Phases"
• Expand "Link Binary with Libraries"
• Click on a (+) button at the left bottom side , which is used to add the library to the selected bundle project
• Find libsqlite3.0.dylib
• Click on the Add button

Now you Project should work properly