IOS开发数据库篇 --- FMDatabaseQueue数据库队列安全操作

#import "FMDB.h"

@interface CZViewController ()

- (IBAction)insertOnClick;
- (IBAction)deleteOnClick;
- (IBAction)updateOnClick;
- (IBAction)queryOnClick;

//@property (nonatomic, strong) FMDatabase *db;
@property (nonatomic, strong) FMDatabaseQueue *queue;
@end

@implementation CZViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    // 0.获取沙盒地址
    NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];
    NSString *sqlFilePath = [path stringByAppendingPathComponent:@"student.sqlite"];
   
   
    // 1.创建一个FMDatabaseQueue对象
    // 只要创建数据库队列对象, FMDB内部就会自动给我们加载数据库对象
    self.queue = [FMDatabaseQueue databaseQueueWithPath:sqlFilePath];
   
    // 2.执行操作
    // 会通过block传递队列中创建好的数据库给我们
    [self.queue inDatabase:^(FMDatabase *db) {
        // 编写需要执行的代码
        // 2.1创建表(在FMDB框架中, 增加/删除/修改/创建/销毁都统称为更新)
        BOOL success = [db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_student (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, score REAL DEFAULT 1);"];
       
        if (success) {
            NSLog(@"创建表成功");
        }else
        {
            NSLog(@"创建表失败");
        }

    }];
   
    /*
    // 1.加载数据库对象
    self.db = [FMDatabase databaseWithPath:sqlFilePath];
   
    // 2.打开数据库
    if([self.db open])
    {
        NSLog(@"打开成功");
        // 2.1创建表(在FMDB框架中, 增加/删除/修改/创建/销毁都统称为更新)
        BOOL success = [self.db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_student (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, score REAL DEFAULT 1);"];
       
        if (success) {
            NSLog(@"创建表成功");
        }else
        {
            NSLog(@"创建表失败");
        }
       
    }else
    {
        NSLog(@"打开失败");
    }
     */
}

- (IBAction)insertOnClick
{
    /*
    // FMDB中可以用?当作占位符, 但是需要注意: 如果使用问号占位符, 以后只能给占位符传递对象
     BOOL success = [self.db executeUpdate:@"INSERT INTO t_student(score, name) VALUES (?, ?);", @(20), @"Jack"];
    if (success) {
        NSLog(@"插入成功");
    }else
    {
        NSLog(@"插入失败");
    }
     */
   
    [self.queue inDatabase:^(FMDatabase *db) {
        BOOL success = [db executeUpdate:@"INSERT INTO t_student(score, name) VALUES (?, ?);", @(20), @"jackson"];
        if (success) {
            NSLog(@"插入成功");
        }else
        {
            NSLog(@"插入失败");
        }

    }];
   
}
- (IBAction)deleteOnClick
{
   
}
- (IBAction)updateOnClick
{
    /*
    [self.queue inDatabase:^(FMDatabase *db) {
       
        // 开启事务
        [db beginTransaction];
       
        [db executeUpdate:@"UPDATE t_student SET score = 1500 WHERE name = 'zs';"];
       
        NSArray *array = @[@"abc"];
        array[1];
       
        [db executeUpdate:@"UPDATE t_student SET score = 500 WHERE name = 'ls';"];
        // 提交事务
        [db commit];
    }];
     */
   
    [self.queue inTransaction:^(FMDatabase *db, BOOL *rollback) {
        [db executeUpdate:@"UPDATE t_student SET score = 1500 WHERE name = 'zs';"];
       
        NSArray *array = @[@"abc"];
//        array[1];
       
        [db executeUpdate:@"UPDATE t_student SET score = 500 WHERE name = 'ls';"];
    }];
}
- (IBAction)queryOnClick
{
    /*
    // FMDB框架中查询用executeQuery方法
    // FMResultSet结果集, 结果集其实和tablevivew很像
    FMResultSet *set = [self.db executeQuery:@"SELECT id, name, score FROM t_student;"];
    while ([set next]) { // next方法返回yes代表有数据可取
        int ID = [set intForColumnIndex:0];
//        NSString *name = [set stringForColumnIndex:1];
        NSString *name = [set stringForColumn:@"name"]; // 根据字段名称取出对应的值
        double score = [set doubleForColumnIndex:2];
        NSLog(@"%d %@ %.1f", ID, name, score);
    }
     */
   
    [self.queue inDatabase:^(FMDatabase *db) {
        // FMResultSet结果集, 结果集其实和tablevivew很像
        FMResultSet *set = [db executeQuery:@"SELECT id, name, score FROM t_student;"];
        while ([set next]) { // next方法返回yes代表有数据可取
            int ID = [set intForColumnIndex:0];
            //        NSString *name = [set stringForColumnIndex:1];
            NSString *name = [set stringForColumn:@"name"]; // 根据字段名称取出对应的值
            double score = [set doubleForColumnIndex:2];
            NSLog(@"%d %@ %.1f", ID, name, score);
        }
    }];
   
   
}


@end