IOS: Learn notes, use Fmdatabase to manipulate sqlite3

Using Fmdatabase to operate Sqlite3 database is very simple and convenient

1 //2 //main.m3 //Iosdemo0602_sqlite34 //5 //Created by Yao_yu on 14-6-2.6 //Copyright (c) 2014 Yao_yu. All rights reserved.7 //8 9 #import<UIKit/UIKit.h>Ten #import "FMDatabase.h" One  A voidtest01 (); -BOOL Isfile (NSString *path); -BOOL Isdir (NSString *path); the  - intMainintargcChar*argv[]) - { - @autoreleasepool { + test01 (); -     } +     return 0; A } at  - voidtest01 () - { -Nsarray *paths =nssearchpathfordirectoriesindomains (Nsdocumentationdirectory, Nsuserdomainmask, YES); -NSString *docpath = [Paths Objectatindex:0]; -NSString *dbpath = [Docpath stringbyappendingpathcomponent:@"Yy/data2"]; in //NSLog (@ "%@", DBPath); -     if(!Isdir (DBPath)) { toNsfilemanager *filemanager =[Nsfilemanager Defaultmanager]; + [FileManager createdirectoryatpath:dbpath withintermediatedirectories:yes attributes:nil Error:nil]; -     } the      *NSString *dbfile = [DBPath stringbyappendingpathcomponent:@"data.db"]; $NSLog (@"%@", dbfile);Panax Notoginseng      -     //Initialize theFmdatabase *db =[Fmdatabase databasewithpath:dbfile]; +     //Open Database A [DB open]; the      +     //Delete a table -[DB executeupdate:@"drop table Persons"]; $      $     //Add Table -[DB executeupdate:@"CREATE TABLE persons (ID, name)"]; -      the     //Delete old data -[DB executeupdate:@"Delete from persons"];Wuyi      the     //using transactions to add data - [DB BeginTransaction]; Wu      for(intI=0; i<10000; i++) -     { About[DB executeupdate:@"INSERT into persons values (?,?)", [NSString stringWithFormat:@"%d", I], [NSString stringWithFormat:@"section%d", I]]; $     } - [DB commit]; -      -     //data Query AFmresultset *cursor = [db executeQuery:@"SELECT * FROM Persons"]; +     intNCols =Cursor.columncount; the      while([cursor next]) { -          for(intI=0; i<ncols; i++) { $printf"%s", [[Cursor stringforcolumnindex:i] utf8string]); the         } theprintf"\ n"); the     } thecursor =Nil; -      in     //Close the database the [DB close]; the      About     //To Delete a database test file the [[Nsfilemanager Defaultmanager] Removeitematpath:dbfile Error:nil]; the      the } +  -BOOL Isfile (NSString *path) the {BayiNsfilemanager *filemanager =[Nsfilemanager Defaultmanager]; theBOOL Isdir =NO; the     if([FileManager fileexistsatpath:path isdirectory: &Isdir]) { -         returnIsdir = =NO; -     } the     returnNO; the } the  theBOOL Isdir (NSString *path) - { theNsfilemanager *filemanager =[Nsfilemanager Defaultmanager]; theBOOL Isdir =NO; the     if([FileManager fileexistsatpath:path isdirectory: &Isdir]) {94         returnIsdir = =YES; the     } the     returnNO; the}