IOS-FMDB
Posted IOS_Bowen
tags:
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一、FMDB简介
FMDatabase *db = [FMDatabase databaseWithPath:path];
if (![db open]) {
NSLog(@"数据库打开失败！");
}
[db executeUpdate:@"UPDATE t_student SET age = ? WHERE name = ?;", @20, @"Jack"]
五、执行查询
// 查询数据
FMResultSet *rs = [db executeQuery:@"SELECT * FROM t_student"];
// 遍历结果集
while ([rs next]) {
NSString *name = [rs stringForColumn:@"name"];
int age = [rs intForColumn:@"age"];
double score = [rs doubleForColumn:@"score"];
}
六、FMDatabaseQueue
FMDatabaseQueue *queue = [FMDatabaseQueue databaseQueueWithPath:path];
[queue inDatabase:^(FMDatabase *db) {
[db executeUpdate:@"INSERT INTO t_student(name) VALUES (?)", @"Jack"];
[db executeUpdate:@"INSERT INTO t_student(name) VALUES (?)", @"Rose"];
[db executeUpdate:@"INSERT INTO t_student(name) VALUES (?)", @"Jim"];
FMResultSet *rs = [db executeQuery:@"select * from t_student"];
while ([rs next]) {
// …
}
}];
[queue inTransaction:^(FMDatabase *db, BOOL *rollback) {
[db executeUpdate:@"INSERT INTO t_student(name) VALUES (?)", @"Jack"];
[db executeUpdate:@"INSERT INTO t_student(name) VALUES (?)", @"Rose"];
[db executeUpdate:@"INSERT INTO t_student(name) VALUES (?)", @"Jim"];
FMResultSet *rs = [db executeQuery:@"select * from t_student"];
while ([rs next]) {
// …
}
}];
*rollback = YES;
我的代码
1 // 2 // ViewController.m 3 // IOS_0331_SQLite3 4 // 5 // Created by ma c on 16/3/31. 6 // Copyright © 2016年 博文科技. All rights reserved. 7 // 8 9 #import "ViewController.h" 10 #import "FMDB.h" 11 12 @interface ViewController () 13 14 @property (nonatomic, strong) FMDatabase *db; 15 16 17 - (IBAction)insert; 18 - (IBAction)update; 19 - (IBAction)query; 20 - (IBAction)delete; 21 22 @end 23 24 @implementation ViewController 25 26 - (void)viewDidLoad { 27 [super viewDidLoad]; 28 29 [self createDatabase]; 30 } 31 32 - (void)createDatabase 33 { 34 // 0.获得沙盒中的数据库文件名 35 NSString *fileName = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"student.sqlite"]; 36 NSLog(@"%@",fileName); 37 38 // 1.创建数据库实例对象 39 self.db = [FMDatabase databaseWithPath:fileName]; 40 41 // 2.打开数据库 42 if ([self.db open]) { 43 NSLog(@"数据库打开成功"); 44 45 //创表 46 BOOL flag = [self.db executeUpdate:@"create table if not exists t_student (id integer primary key autoincrement, name text, age integer) ;"]; 47 if (flag) { 48 NSLog(@"建表成功"); 49 } else { 50 NSLog(@"建表失败"); 51 } 52 } else { 53 NSLog(@"数据库打开失败"); 54 } 55 } 56 57 - (IBAction)insert { 58 59 [self.db executeUpdate:@"insert into t_student (name, age) values (?, ?);",@"rose",@10]; 60 61 } 62 63 - (IBAction)update { 64 65 [self.db executeUpdate:@"update t_student set age = ? where name = ?;",@20, @"rose"]; 66 } 67 68 - (IBAction)query { 69 //1.查询数据 70 FMResultSet *rs = [self.db executeQuery:@"select * from t_student;"]; 71 //2.遍历结果集 72 while (rs.next) { 73 int ID = [rs intForColumn:@"id"]; 74 NSString *name = [rs stringForColumn:@"name"]; 75 int age = [rs intForColumn:@"age"]; 76 77 NSLog(@"%d %@ %d",ID, name, age); 78 } 79 80 } 81 82 - (IBAction)delete { 83 84 [self.db executeUpdate:@"delete from t_student where name = ?;",@"rose"]; 85 86 } 87 @end
线程安全和事物
1 // 2 // IWViewController.m 3 // 01-SQLite的基本使用 4 // 5 // Created by apple on 14-5-22. 6 // Copyright (c) 2014年 itcast. All rights reserved. 7 // 8 9 #import "IWViewController.h" 10 #import "FMDB.h" 11 12 @interface IWViewController () 13 @property (nonatomic, strong) FMDatabaseQueue *queue; 14 - (IBAction)insert; 15 - (IBAction)update; 16 - (IBAction)delete; 17 - (IBAction)query; 18 @end 19 20 @implementation IWViewController 21 22 - (void)viewDidLoad 23 { 24 [super viewDidLoad]; 25 26 // 0.获得沙盒中的数据库文件名 27 NSString *filename = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"student.sqlite"]; 28 29 // 1.创建数据库队列 30 self.queue = [FMDatabaseQueue databaseQueueWithPath:filename]; 31 32 // 2.创表 33 [self.queue inDatabase:^(FMDatabase *db) { 34 BOOL result = [db executeUpdate:@"create table if not exists t_student (id integer primary key autoincrement, name text, age integer);"]; 35 36 if (result) { 37 NSLog(@"创表成功"); 38 } else { 39 NSLog(@"创表失败"); 40 } 41 }]; 42 } 43 44 - (IBAction)insert 45 { 46 [self.queue inDatabase:^(FMDatabase *db) { 47 for (int i = 0; i<40; i++) { 48 NSString *name = [NSString stringWithFormat:@"rose-%d", arc4random() % 1000]; 49 NSNumber *age = @(arc4random() % 100 + 1); 50 [db executeUpdate:@"insert into t_student (name, age) values (?, ?);", name, age]; 51 } 52 }]; 53 } 54 55 - (IBAction)update 56 { 57 [self.queue inDatabase:^(FMDatabase *db) { 58 // 开启事务 59 // [db executeUpdate:@"begin transaction;"]; 60 // [db beginTransaction]; 61 62 [db executeUpdate:@"update t_student set age = ? where name = ?;", @20, @"jack"]; 63 [db executeUpdate:@"update t_student set age = ? where name = ?;", @20, @"jack"]; 64 65 66 // if (发现情况不对){ 67 // // 回滚事务 68 // [db rollback]; 69 //// [db executeUpdate:@"rollback transaction;"]; 70 // } 71 72 73 [db executeUpdate:@"update t_student set age = ? where name = ?;", @20, @"jack"]; 74 75 // 提交事务 76 // [db commit]; 77 // [db executeUpdate:@"commit transaction;"]; 78 }]; 79 } 80 81 - (IBAction)delete 82 { 83 [self.queue inTransaction:^(FMDatabase *db, BOOL *rollback) { 84 [db executeUpdate:@"update t_student set age = ? where name = ?;", @20, @"jack"]; 85 [db executeUpdate:@"update t_student set age = ? where name = ?;", @20, @"jack"]; 86 87 // if (发现情况不对){ 88 // // 回滚事务 89 // *rollback = YES; 90 // } 91 }]; 92 } 93 94 - (IBAction)query 95 { 96 [self.queue inDatabase:^(FMDatabase *db) { 97 // 1.查询数据 98 FMResultSet *rs = [db executeQuery:@"select * from t_student where age > ?;", @50]; 99 100 // 2.遍历结果集 101 while (rs.next) { 102 int ID = [rs intForColumn:@"id"]; 103 NSString *name = [rs stringForColumn:@"name"]; 104 int age = [rs intForColumn:@"age"]; 105 106 NSLog(@"%d %@ %d", ID, name, age); 107 } 108 }]; 109 } 110 @end
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