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FMDB 增刪改查

1. FMDB 優(yōu)點(diǎn):
   [1] 使用起來(lái)更加面向?qū)ο?，省去了很多麻煩、冗余的C語(yǔ)言代碼
   [2] 對(duì)比蘋(píng)果自帶的Core Data框架，更加輕量級(jí)和靈活
   [3] 提供了多線程安全的數(shù)據(jù)庫(kù)操作方法，有效地防止數(shù)據(jù)混亂

2. 核心類(lèi)
   [1] FMDatabase:
   一個(gè)FMDatabase對(duì)象就代表一個(gè)單獨(dú)的SQLite數(shù)據(jù)庫(kù)
   用來(lái)執(zhí)行SQL語(yǔ)句
   [2] FMResultSet:
   使用FMDatabase執(zhí)行查詢(xún)后的結(jié)果集
   [3] FMDatabaseQueue:
   用于在多線程中執(zhí)行多個(gè)查詢(xún)或更新，它是線程安全的

#import "FMDBModel.h"
#import "FMDB.h"
// 創(chuàng)建數(shù)據(jù)庫(kù)
NSString *create = @"CREATE TABLE IF NOT EXISTS t_GESTURE (iPhone text NOT NULL ,password text NOT NULL)";

//delete from是刪除關(guān)鍵字，后面是要?jiǎng)h的表名，然后可以選擇跟一個(gè)where限制，限制參考修改
NSString *delete = @"delete from t_GESTURE where iPhone = ?";

//update是修改的關(guān)鍵字，后面是t_GESTURE表名，set表示修改動(dòng)作的關(guān)鍵字，set后面跟著被改的字段名及其要改的內(nèi)容(要改的內(nèi)容也可以是?)，再后面可以加where限制，也可以不加，where后面是字段=內(nèi)容的結(jié)構(gòu)，內(nèi)容同樣可以為?
NSString *updateTable = @"update t_GESTURE set password = ? where iPhone = ?";

// 查詢(xún)數(shù)據(jù)庫(kù)
NSString *selectTable = @"SELECT * FROM t_GESTURE";

@interface FMDBModel ()
@property (nonatomic,strong) FMDatabase *db;
@end
@implementation FMDBModel
+(FMDBModel *)fModel{
static FMDBModel *fModel = nil;
  static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
    if (!fModel) {
         fModel = [[FMDBModel alloc] init];
        NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"FMDB.sqlite"];
        FMDatabase *db = [FMDatabase databaseWithPath:path];
        [db open];
        NSLog(@"%@",path);
        [db executeUpdate:create];
        [db close];
        fModel.db = db;
    }
});
return  fModel;
}

- (void)insert{
[self.db open];
BOOL isInsert = [self.db executeUpdate:@"insert into t_GESTURE(iphone,password) VALUES (?,?)",self.phone,self.password];
if (isInsert) {
    NSLog(@"插入成功");
}
[self.db close];
}
- (void)Delete{
[self.db open];
//2、調(diào)用刪除語(yǔ)句
BOOL isDelCharactor = [self.db executeUpdate:delete,self.phone];
if (isDelCharactor) {
    NSLog(@"成功");
}
[self.db close];
}
- (void)change{
[self.db open];
//2、調(diào)用修改語(yǔ)句
BOOL isUpdate = [self.db executeUpdate:updateTable,self.password,self.phone];
if(isUpdate == NO)
{
    NSLog(@"修改失敗");
    return;
}else{
    NSLog(@"修改成功");
}
[self.db close];
}
- (void)query{
[self.db open];
// 查詢(xún)
FMResultSet *resultSet = [self.db executeQuery:selectTable];
while ([resultSet next]) {
    NSString *phone = [resultSet stringForColumn:@"iPhone"];
    NSString *password = [resultSet stringForColumn:@"password"];
    NSLog(@" %@ %@",phone,password);
}
[self.db close];
}

使用

// 插入
- (IBAction)ConfirmDown:(id)sender {
[FMDBModel fModel].phone = self.iPhone.text;
[FMDBModel fModel].password = self.password.text;
[[FMDBModel fModel] insert];
}

// 查詢(xún)
- (IBAction)SelectDown:(id)sender {
[[FMDBModel fModel] query];
}

// 刪除
- (IBAction)Delete:(id)sender {
[FMDBModel fModel].phone = self.iPhone.text;
[FMDBModel fModel].password = self.password.text;
[[FMDBModel fModel] Delete];
}
// 修改
- (IBAction)change:(id)sender {
[FMDBModel fModel].phone = self.iPhone.text;
[FMDBModel fModel].password = self.password.text;
[[FMDBModel fModel] change];
}