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FMDB使用(转载)

时间:2015-10-12 10:36:37      阅读:258      评论:0      收藏:0      [点我收藏+]

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1、首先要先导入第三方类库FMdatabase。

2、获得存放数据库文件的沙盒地址。

 

1 +(NSString *)databaseFilePath
2 {
3  
4 NSArray *filePath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
5 NSString *documentPath = [filePath objectAtIndex:0];
6 NSLog(@"%@",filePath);
7 NSString *dbFilePath = [documentPath stringByAppendingPathComponent:@"db.sqlite"];
8 return dbFilePath;
9  
10 }

 

3、创建数据库的操作

 

1 +(void)creatDatabase
2 {
3 db = [[FMDatabasedatabaseWithPath:[selfdatabaseFilePath]] retain];
4 }

 

4、创建表

 

1 +(void)creatTable
2 {
3 //先判断数据库是否存在,如果不存在,创建数据库
4 if (!db) {
5 [selfcreatDatabase];
6 }
7 //判断数据库是否已经打开,如果没有打开,提示失败
8 if (![db open]) {
9 NSLog(@"数据库打开失败");
10 return;
11 }
12  
13 //为数据库设置缓存,提高查询效率
14 [dbsetShouldCacheStatements:YES];
15  
16 //判断数据库中是否已经存在这个表,如果不存在则创建该表
17 if(![dbtableExists:@"people"])
18 {
19 [db executeUpdate:@"CREATE TABLES people(people_id INTEGER PRIMARY KEY AUTOINCREAMENT, name TEXT, age INTEGER) "];
20  
21  
22 NSLog(@"创建完成");
23 }
24  
25 }

 

5、增加表数据

 

1 +(void)insertPeople:(People *)aPeople
2 {
3 if (!db) {
4 [selfcreatDatabase];
5 }
6  
7 if (![db open]) {
8 NSLog(@"数据库打开失败");
9 return;
10 }
11  
12 [dbsetShouldCacheStatements:YES];
13  
14 if(![dbtableExists:@"people"])
15 {
16 [selfcreatTable];
17 }
18 //以上操作与创建表是做的判断逻辑相同
19 //现在表中查询有没有相同的元素,如果有,做修改操作
20 FMResultSet *rs = [dbexecuteQuery:@"select * from people where people_id = ?",[NSStringstringWithFormat:@"%d",aPeople.peopleID]];
21 if([rs next])
22 {
23 NSLog(@"dddddslsdkien");
24 [dbexecuteUpdate:@"update people set name = ?, age = ? where people_id = 1",aPeople.name,[NSStringstringWithFormat:@"%d",aPeople.age]];
25 }
26 //向数据库中插入一条数据
27 else{
28 [dbexecuteUpdate:@"INSERT INTO people (name, age) VALUES (?,?)",aPeople.name,[NSStringstringWithFormat:@"%d",aPeople.age]];
29 }
30  
31 }

 

6、删除数据

 

1 +(void)deletePeopleByID:(int)ID
2 {
3 if (!db) {
4 [selfcreatDatabase];
5 }
6  
7 if (![db open]) {
8 NSLog(@"数据库打开失败");
9 return;
10 }
11  
12 [dbsetShouldCacheStatements:YES];
13  
14 //判断表中是否有指定的数据, 如果没有则无删除的必要,直接return
15 if(![dbtableExists:@"people"])
16 {
17 return;
18 }
19 //删除操作
20 [db executeUpdate:@"delete from people where people_id = ?", [NSStringstringWithFormat:@"%d",ID]];
21  
22 [db close];
23 }

 

7、修改操作与增加操作的步骤一致

8、查询

 

1 +(NSArray *)getAllPeople
2 {
3  
4 if (!db) {
5 [selfcreatDatabase];
6 }
7  
8 if (![db open]) {
9 NSLog(@"数据库打开失败");
10 return nil;
11 }
12  
13 [dbsetShouldCacheStatements:YES];
14  
15 if(![dbtableExists:@"people"])
16 {
17 return nil;
18 }
19  
20 //定义一个可变数组,用来存放查询的结果,返回给调用者
21 NSMutableArray *peopleArray = [[NSMutableArrayalloc] initWithArray:0];
22 //定义一个结果集,存放查询的数据
23 FMResultSet *rs = [dbexecuteQuery:@"select * from people"];
24 //判断结果集中是否有数据,如果有则取出数据
25 while ([rs next]) {
26 People *aPeople = [[People alloc] init];
27  
28 aPeople.peopleID = [rs intForColumn:@"people_id"];
29 aPeople.name = [rs stringForColumn:@"name"];
30 aPeople.age = [rs intForColumn:@"age"];
31 //将查询到的数据放入数组中。
32 [peopleArray addObject:aPeople];
33 }
34 return [peopleArray autorelease];
35 }
 

FMDB使用(转载)

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原文地址:http://www.cnblogs.com/xiaoxiaoyublogs/p/4870737.html

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