数据库存取数据

BirdMichael

2016-01-10

OC

static FMDatabase *_db;

(void)initialize
{
NSString cachePath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
// 拼接文件名
NSString filePath = [cachePath stringByAppendingPathComponent:@”onLineHome.sqlite”];
// 创建了一个数据库实例
_db = [FMDatabase databaseWithPath:filePath];

// 打开数据库
if ([_db open]) {
```
NSLog(@"打开成功");
```
}else{
```
NSLog(@"打开失败");
```
}

// 创建t_online_home表格
BOOL flag = [_db executeUpdate:@”create table if not exists t_online_home (id integer primary key autoincrement,tagid text,dict text);”];
if (flag) {
```
NSLog(@"t_online_home 可用");
```
}else{
```
NSLog(@"t_online_home 创建失败");
```
}
}
(void)saveWithOnlineVC:(NSDictionary )onlinevc withTagId:(NSNumber )tagid{
BOOL isHaveRet = NO;
NSString sel = [NSString stringWithFormat:@”select from t_online_home where tagid = ‘%@’;”,tagid];
FMResultSet * set = [_db executeQuery:sel];
while ([set next]) {
```
isHaveRet = YES;
break;
```
}
NSString sql = nil;
NSString json = [YYUtil json2String:onlinevc];
if (isHaveRet) {
```
sql = [NSString stringWithFormat:@"UPDATE t_online_home SET dict = '%@' WHERE tagid = '%@';", json,tagid];
```
}else{
```
sql = [NSString stringWithFormat:@"insert into t_online_home (tagid,dict) values('%@','%@')",tagid ,json];
```
}
BOOL ret = [_db executeUpdate:sql];

if (ret) {
```
NSLog(@"update successed");
```
}else{
```
NSLog(@"%@", [_db lastErrorMessage]);
```
}

}

(NSDictionary )onlineVCWithTagId:(NSNumber )tagid{
// 进入程序第一次获取的查询语句
NSString sql = [NSString stringWithFormat:@”select from t_online_home where tagid = ‘%@’;”,tagid];
FMResultSet *set = [_db executeQuery:sql];
while ([set next]) {
```
NSString *json = [set stringForColumn:@"dict"];
NSDictionary *dict = [YYUtil string2Json:json];
NSLog(@"%@",dict);
return dict;
```
}
return nil;

}