#import "ViewController.h"

#import "FMDB.h"

@interface ViewController ()

- (IBAction)insert;

- (IBAction)update;

- (IBAction)delete;

- (IBAction)select;

@property (nonatomic, strong) FMDatabase *db;

@end

@implementation ViewController

- (void)viewDidLoad

{

    [super viewDidLoad];

    // 获得数据库文件的路径

    NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];

    NSString *filepath = [docPath stringByAppendingPathComponent:@"s.sqlite"];

    // 通过数据文件路径创建数据库对象

    self.db = [FMDatabase databaseWithPath:filepath];

    //打开数据库

    if ([self.db open]) {

        NSLog(@"打开数据库成功");

        //创表

        BOOL success = [self.db executeUpdate:@"create table if not exists t_student (id integer primary key autoincrement, name text not null, age integer not null);"];

        if (success) {

            NSLog(@"创表成功");

        } else {

            NSLog(@"创表失败");

        }

    } else {

        NSLog(@"打开数据库失败");

    }

}

- (IBAction)insert {

    for (int i = 0; i<100; i++) {

        NSString *name = [NSString stringWithFormat:@"cxs-%d", i];

        int age = arc4random_uniform(100);

        [self.db executeUpdate:@"insert into t_student (name, age) values(?, ?);", name, @(age)];

    }

}

- (IBAction)update {

    [self.db executeUpdate:@"update t_student set name = ? where age < ?;", @"cxs-3", @50];

}

- (IBAction)delete {

    [self.db executeUpdate:@"delete from t_student where age < ?;", @50];

}

- (IBAction)select {

    // 查询数据, 获得查询结果集

    FMResultSet *set = [self.db executeQuery:@"select * from t_student where name like ?;", @"%cxs-5%"];

    //从结果集里面取出数据

    while ([set next]) {

        // 取出当期指向的那行数据

        NSString *name =  [set stringForColumn:@"name"];

        int age = [set intForColumn:@"age"];

        NSLog(@"%@ - %d", name, age);

    }

}