在.m文件 定義宏，方面後面使用

1. #define DBNAME @"personinfo.sqlite"
2. #define NAME @"name"
3. #define AGE @"age"
4. #define ADDRESS @"address"
5. #define TABLENAME @"PERSONINFO"
   
   
   1. NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
   2. NSString *documents = [paths objectAtIndex:0];
   3. NSString *database_path = [documents stringByAppendingPathComponent:DBNAME];
   5. if (sqlite3_open([database_path UTF8String], &db) != SQLITE_OK) {
   6. sqlite3_close(db);
   7. NSLog(@"數據庫打開失敗");
   8. }
      

      sqlite3_open，如果數據不存在，則創建。運行。這是在沙盒目錄下能看到數據庫文件（如何打開模擬器沙盒目錄請參考：iOS學習之iOS沙盒(sandbox)機制和文件操作(一)）

      
      

      
      

      4、創建數據表

      創建一個獨立的執行sql語句的方法，傳入sql語句，就執行sql語句

      
      
      1. -(void)execSql:(NSString *)sql
      2. {
      3. char *err;
      4. if (sqlite3_exec(db, [sql UTF8String], NULL, NULL, &err) != SQLITE_OK) {
      5. sqlite3_close(db);
      6. NSLog(@"數據庫操作數據失敗!");
      7. }
      8. } 創建數據表PERSONINFO的語句
         
         
         1. NSString *sqlCreateTable = @"CREATE TABLE IF NOT EXISTS PERSONINFO (ID INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER, address TEXT)";
         2. [self execSql:sqlCreateTable]; 運行程序，數據表創建了。怎麼知道數據表創建了呢？我們用火狐的Sqlite Manager插件工具打開數據庫文件看看。可以在火狐浏覽器裡安裝這個插件。打開

            
            

            四個字段都出現是表中了。

            5、插入數據：

            
            
            1. NSString *sql1 = [NSString stringWithFormat:
            2. @"INSERT INTO '%@' ('%@', '%@', '%@') VALUES ('%@', '%@', '%@')",
            3. TABLENAME, NAME, AGE, ADDRESS, @"張三", @"23", @"西城區"];
            5. NSString *sql2 = [NSString stringWithFormat:
            6. @"INSERT INTO '%@' ('%@', '%@', '%@') VALUES ('%@', '%@', '%@')",
            7. TABLENAME, NAME, AGE, ADDRESS, @"老六", @"20", @"東城區"];
            8. [self execSql:sql1];
            9. [self execSql:sql2]; 運行程序，插入兩條數據，用火狐的sqlite工具查看

               
               

               6、查詢數據庫並打印數據

               
               
               1. NSString *sqlQuery = @"SELECT * FROM PERSONINFO";
               2. sqlite3_stmt * statement;
               4. if (sqlite3_prepare_v2(db, [sqlQuery UTF8String], -1, &statement, nil) == SQLITE_OK) {
               5. while (sqlite3_step(statement) == SQLITE_ROW) {
               6. char *name = (char*)sqlite3_column_text(statement, 1);
               7. NSString *nsNameStr = [[NSString alloc]initWithUTF8String:name];
               9. int age = sqlite3_column_int(statement, 2);
               11. char *address = (char*)sqlite3_column_text(statement, 3);
               12. NSString *nsAddressStr = [[NSString alloc]initWithUTF8String:address];
               14. NSLog(@"name:%@ age:%d address:%@",nsNameStr,age, nsAddressStr);
               15. }
               16. }
               17. sqlite3_close(db); 打印結果：
                   [cpp] view plaincopy
                   1. 2012-06-29 13:25:32.205 sqlitDemo[3587:f803] name:張三 age:23 address:西城區
                   2. 2012-06-29 13:25:32.206 sqlitDemo[3587:f803] name:老六 age:20 addre