iOS数据存储-FMDB

FMDB是建立在SQLite之上的，以OC的语法封装了SQLite的C语言API，使用起来更加面向对象。可以存储数据类型:TEXT(字符串)、INTEGER(整型)、BLOB(二进制)、BOOLEAN(布尔)、DATE(数据)。

• FMDatabase - 代表SQLite 数据库的类，用于执行 SQL 语句
• FMResultSet - 代表在 FMDatabase中执行查询的结果的类
• FMDatabaseQueue - 如果您想在多线程上执行查询和更新，会使用这个类

示例

FMDB.gif

用法

• 创建数据库

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,  NSUserDomainMask, YES);
NSString *documents = [paths objectAtIndex:0];
 NSString *path = [documents stringByAppendingPathComponent:@"sampleDB_1.0.0.db"];
_dataBase = [FMDatabase databaseWithPath:path];
if([_dataBase open]){
[_dataBase executeUpdate:@"CREATE TABLE IF NOT EXISTS sampleTable(name TEXT,age NEXT)"];
[_dataBase close];
      NSLog(@"数据库创建打开成功");
  }else{
      NSLog(@"数据库创建打开失败");
  }

• 添加数据

NSArray *array = [NSArray array];
if ([self isOpenDatabese:_dataBase]) {
FMResultSet *result =  [_dataBase executeQuery:[NSString stringWithFormat:@"SELECT * FROM sampleTable WHERE %@ LIMIT 1",[self getDBWhereStrWithDic:dic]]];
 array =  [self getArrWithFMResultSet:result keyTypes:@{@"name":@"TEXT", @"age":@"TEXT"}];}
 //如果数据已存在，则更新数据
  if (array.count) {
 if ([self isOpenDatabese:_dataBase]) {
 NSMutableString *sql = [[NSMutableString alloc] initWithString:[NSString stringWithFormat:@"UPDATE sampleTable SET %@ WHERE %@", [self getDBSetStrWithDic:dic], [self getDBWhereStrWithDic:dic]]];
[_dataBase executeUpdate:sql];
 }
}else{ //否则插入数据
      if ([self isOpenDatabese:_dataBase]) {
      NSArray *keys = [dic allKeys];
      NSArray *values = [dic allValues];
      NSMutableString *sql = [[NSMutableString alloc] initWithString:[NSString stringWithFormat:@"INSERT INTO sampleTable ("]];
      NSInteger count = 0;
      for (NSString *key in keys) {
      [sql appendString:key];
      count ++;
      if (count < [keys count]) {
      [sql appendString:@", "];
      }
      }
      [sql appendString:@") VALUES ("];
      for (int i = 0; i < [values count]; i++) {
      [sql appendString:@"?"];
      if (i < [values count] - 1) {
      [sql appendString:@","];
      }
      }
      [sql appendString:@")"];
      [_dataBase executeUpdate:sql withArgumentsInArray:values];
      }
    }
    [_dataBase close];

• 删除数据

// 删除表中所有数据
if ([self isOpenDatabese:_dataBase]) {
      [_dataBase executeUpdate:@"DELETE FROM sampleTable"];
  }
 [_dataBase close];
// 删除单条数据sql语句
DELETE FROM sampleTable WHERE xx = ? 

• 修改数据

if ([self isOpenDatabese:_dataBase]) {
NSMutableString *sql = [[NSMutableString alloc] initWithString:[NSString stringWithFormat:@"UPDATE sampleTable SET %@ WHERE %@", [self getDBSetStrWithDic:dic], [self getDBWhereStrWithDic:dic]]];
[_dataBase executeUpdate:sql];
}

• 数据查询

FMResultSet *resRoute = [_dataBase executeQuery:@"select * from sampleTable"];

注意：只是复制粘贴代码的同学，肯定报错，部分方法是封装过的。详细用法请看demo