Sqlite3数据库未执行查询

Question

我正在Xcode中开发iPhone应用程序，我无法访问我创建的数据库。以下是我在哪里创建我的数据库

//create local database 
NSString *docsDir; 
NSArray *dirPaths; 
sqlite3 *localDB; 

// Get the documents directory 
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
docsDir = [dirPaths objectAtIndex:0]; 

// Build the path to the database file 
databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent: @"local.db"]]; 

NSFileManager *filemgr = [NSFileManager defaultManager]; 

if ([filemgr fileExistsAtPath: databasePath ] == NO) { 
    const char *dbpath = [databasePath UTF8String]; 

    if (sqlite3_open(dbpath, &localDB) == SQLITE_OK) { 
     char *errMsg; 
     const char *sql_stmt1 = "CREATE TABLE IF NOT EXISTS My_choices (perfume_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, na TEXT, got_it TEXT)"; 

     const char *sql_stmt2 = "CREATE TABLE IF NOT EXISTS Ratings (perfume_id INTEGER PRIMARY KEY AUTOINCREMENT, rating NUMERIC)"; 

     const char *sql_stmt3 = "CREATE TABLE IF NOT EXISTS Consultant_Details (_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT,website TEXT,domain TEXT,domain_no NUMERIC,phone TEXT,facebook TEXT)"; 

     if (sqlite3_exec(localDB, sql_stmt1, NULL, NULL, &errMsg) != SQLITE_OK) { 
      NSLog(@"%@",@"Failed to create table My_choices"); 

     } 
     if (sqlite3_exec(localDB, sql_stmt2, NULL, NULL, &errMsg) != SQLITE_OK) { 
      NSLog(@"%@",@"Failed to create table ratings"); 

     } 
     if (sqlite3_exec(localDB, sql_stmt3, NULL, NULL, &errMsg) != SQLITE_OK) { 
      NSLog(@"%@",@"Failed to create table Consultant_Details"); 

     } 


     sqlite3_close(localDB); 
    } 
    else { 
     NSLog(@"%@",@"Failed to open/create database"); 

    } 
} 

下面添加的代码是在哪里我试图访问它

NSString *docsDir; 
NSArray *dirPaths; 
sqlite3 *localDB; 

// Get the documents directory 
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
docsDir = [dirPaths objectAtIndex:0]; 

// Build the path to the database file 
NSString *dbPath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent: @"local.db"]]; 


NSString *q = @"select * from Ratings where perfume_id in"; 

q = [q stringByAppendingString:idList]; 

NSLog(@"%@",q); 
const char *sqlStatement2 = [q UTF8String]; 
sqlite3_stmt *compiledStatement2; 
if(sqlite3_open([dbPath UTF8String], &localDB) == SQLITE_OK) { 
    if(sqlite3_prepare_v2(localDB, sqlStatement2, -1, &compiledStatement2, NULL) == SQLITE_OK) { 

     NSLog(@"%d", SQLITE_ROW); 
     // Loop through the results and add them to the feeds array 
     while(sqlite3_step(compiledStatement2) == SQLITE_ROW) { 


      // Read the data from the result row 
      int r = sqlite3_column_int(compiledStatement2, 1); 
      int id = sqlite3_column_int(compiledStatement2, 0); 
      NSLog(@"%d", id); 

      for (ListItem *item in self.listItemArray) { 

       if(item.perfumeId == id){ 
        item.rating = r; 

       } 
      } 

     } 
    } 
    else{ 
     NSLog(@"query failed: %s", sqlite3_errmsg(localDB)); 
    } 
} 
sqlite3_close(localDB); 

我总是得到的代码“查询失败不存在页表：评价”中我的日志。 任何帮助将不胜感激。

Answer 1

基本上这个错误是由于数据库中的Table无法使用或错误的查询造成的。根据你的帖子，IT看起来像查询中的错误。

查询应该是这样的：

NSString *q = @"select * from Ratings where perfume_id in ('12','13','14','15')"; 

打印您"String q"，并确保它上面的跟随。

Answer 2

感谢大家的帮助。同样的数据库文件已存在于该路径。因此，我的第一个方法是创建数据库 if（[filemgr fileExistsAtPath：databasePath] == NO）检查是否为false，并且未创建表。从文件目录

Answer 3

先删除数据库文件，然后使用下面的代码创建一个SQLite表..

if (![fileManager fileExistsAtPath: _databasePath ]) 
     { 
      const char *dbpath = [_databasePath UTF8String]; 
      if (sqlite3_open(dbpath, &_myDataBase) == SQLITE_OK) 
      { 
       char *errMsg; 
       const char *sql_stmt = 
       "CREATE TABLE IF NOT EXISTS My_choices (perfume_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, na TEXT, got_it TEXT);" //TEST 
       "CREATE TABLE IF NOT EXISTS Ratings (perfume_id INTEGER PRIMARY KEY AUTOINCREMENT, rating NUMERIC);" //USER 
       "CREATE TABLE IF NOT EXISTS Consultant_Details (_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT,website TEXT,domain TEXT,domain_no NUMERIC,phone TEXT,facebook TEXT)"; //METADATA 


       if (sqlite3_exec(_myDataBase, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK) 
       { 
        NSLog(@"Failed to create tables"); 
       } 
       sqlite3_close(_myDataBase); 
       NSLog(@"DataBase created at: %@",_databasePath); 
      } else { 
       NSLog(@"Failed to open/create database"); 
      } 
     }