Question

想知道是否有人可以分享如何从具有多个记录的SQLite中检索数据，即我有一个包含5个字段的表，每个字段都有多个数据。

NSString *str = [[NSString alloc] initWithFormat:@"%@ %@ etc...", oneString,two...];

[entry addObject:str];

我只得到第一条记录

下面的字符串还有一件事

NSString *sql = [NSString stringWithFormat:@"SELECT * FROM abc"];

但是这个没有，我崩溃了！

NSString *sql = [NSString stringWithFormat:@"SELECT * FROM abc WHERE name= \"john\""];

Answer 1

-(NSMutableArray *)readInformationFromDatabase
{
NSMutableArray *array = [[NSMutableArray alloc] init];

// Setup the database object
sqlite3 *database;

// Open the database from the users filessytem
if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK)
{
    // Setup the SQL Statement and compile it for faster access

    //SQLIte Statement 
    NSString *sqlStatement_userInfo =[NSString stringWithFormat:@"Select * from TableName"];

    sqlite3_stmt *compiledStatement;


    if(sqlite3_prepare_v2(database, [sqlStatement_userInfo UTF8String], -1, &compiledStatement, NULL) == SQLITE_OK)
    {

        // Loop through the results and add them to the feeds array
        while(sqlite3_step(compiledStatement) == SQLITE_ROW)
        {
            // Init the Data Dictionary 
            NSMutableDictionary *_dataDictionary=[[NSMutableDictionary alloc] init];

            NSString *_userName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)];
           // NSLog(@"_userName = %@",_userName);

            NSString *_emailID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)];
           // NSLog(@"_emailID = %@",_emailID);

            NSString *_contactNumber = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];
           // NSLog(@"_contactNumber = %@",_contactNumber);

            NSString *_address = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 3)];
           // NSLog(@"_address = %@",_address);

            NSString *_zipCode = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 4)];
           // NSLog(@"_zipCode = %@",_zipCode);

            [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_userName] forKey:@"UserName"];
            [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_emailID] forKey:@"EmailId"];
            [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_contactNumber] forKey:@"ContactNumber"];
            [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_address] forKey:@"Address"];
            [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_zipCode] forKey:@"ZIPCode"];

            [array addObject:_dataDictionary]; 
        }
    }
    else
    {
        NSLog(@"No Data Found");
    }

    // Release the compiled statement from memory
    sqlite3_finalize(compiledStatement);
}

sqlite3_close(database);

return array;
}

Answer 2

您可以使用以下方法：

/ =========================================== =====================
从数据库中获取数据的方法 ================================================== ================ /

-(NSMutableArray *)getData:(NSString *)query
{


//NSLog(@"QUERY : %@",query);

NSString *idToReturn=@"";
NSMutableArray *returnArray = [NSMutableArray new];
if(sqlite3_open([[self dataFilePath] UTF8String], &database) == SQLITE_OK)
{
    sqlite3_stmt *statement;
    if (sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, nil)==SQLITE_OK)
    {
        while(sqlite3_step(statement)==SQLITE_ROW)
        {
            NSMutableDictionary *temp= [NSMutableDictionary new];
            const char *s;



            s=(char *)sqlite3_column_text(statement, 0); // Here 0 is the first column index 
            if(s==NULL)
            {
                idToReturn=@"";
            }
            else
            {
                idToReturn =[NSString stringWithUTF8String:s];
            }
            [temp setObject:idToReturn forKey:@"firstData"];

            s=(char *)sqlite3_column_text(statement, 1);
            if(s==NULL)
            {
                idToReturn=@"";
            }
            else
            {
                idToReturn =[NSString stringWithUTF8String:s];
            }
            [temp setObject:idToReturn forKey:@"secondData"];

            s=(char *)sqlite3_column_text(statement, 2);
            if(s==NULL)
            {
                idToReturn=@"";
            }
            else
            {
                idToReturn =[NSString stringWithUTF8String:s];
            }
            [temp setObject:idToReturn forKey:@"thirdData"];

            s=(char *)sqlite3_column_text(statement, 3);
            if(s==NULL)
            {
                idToReturn=@"";
            }
            else
            {
                idToReturn =[NSString stringWithUTF8String:s];
            }
            [temp setObject:idToReturn forKey:@"forthData"];

            s=(char *)sqlite3_column_text(statement, 5);
            if(s==NULL)
            {
                idToReturn=@"";
            }
            else
            {
                idToReturn =[NSString stringWithUTF8String:s];
            }
            [temp setObject:idToReturn forKey:@"fifthData"];

            if (temp != nil)
            {
                [returnArray addObject:temp];

                temp = nil;
            }

        }
        sqlite3_finalize(statement);
        sqlite3_close(database);
    }
}
return returnArray;

}

然后将其称为：

NSString *query  = [NSString stringWithFormat:@"select * from tablename"];
NSMutableArray *data = [self getData:query];

希望它对你有所帮助。

从具有多个记录的SQLite检索数据

2 个答案: