[error] Undefined symbols for architecture i386: ***

xcode error:Undefined symbols for architecture i386:

How to fix:
This problem was from 2 causes.
1.Unlink Library
 Check using library in your project.
 Build Phases -> Compile Sources -> Link Binary With Libraries
 QuartzCore.framewrok / libsqlite3.0.dyblib and so on.
2.Missed compile target file
 Check “Compile Sources” to all files show on this area.
 Build Phases -> Compile Sources
easy :)