//創(chuàng)建數(shù)據(jù)庫中的表
BOOL stuSql = [db executeUpdate:@"create table if not exists stu(stuid integer primary key autoincrement, name varchar(255),sex varchar(255),age integer)"];

//向數(shù)據(jù)庫中插入數(shù)據(jù)
NSString *insertSql = @"insert into stu(stuid,name,sex,age) values(?,?,?,?)";
BOOL success = [db executeUpdate:insertSql,@"1",[NSString stringWithFormat:@"zxm"],@"男",@20];

//查詢數(shù)據(jù)庫 //查詢所有的數(shù)據(jù)庫數(shù)據(jù)
NSString *selectSql = @"select *from stu";
FMResultSet *result = [db executeQuery:selectSql];
while ([result next]) {
NSLog(@"%@ %@ %@ %d",[result stringForColumn:@"stuid"],[result stringForColumn:@"name"],[result stringForColumn:@"sex"],[result intForColumn:@"age"]);    
}
//通過某個字段檢查是否存在數(shù)據(jù)
NSString * querySql = [NSString stringWithFormat:@"select * from stu where %@='%@'", table,@"男",@20];

//清空數(shù)據(jù)庫
NSString *deleteSql = @"delete from stu";
BOOL success = [db executeUpdate:deleteSql];

//修改數(shù)據(jù)庫中的數(shù)據(jù)    //tian6是新值 代替數(shù)據(jù)庫中name = tian1的值
NSString *updateSql = @"update stu set name = ? where name = ?";
BOOL success  = [db executeUpdate:updateSql,@"tian6",@"tian1"];

iOS中原聲的SQLite API在進行數(shù)據(jù)存儲的時候，需要使用C語言中的函數(shù)，操作比較麻煩，于是就出現(xiàn)了一系列將SQLite封裝的庫。本文講解的FMDB就是其中的一個。

FMDB PK Sqlite

優(yōu)點:

1.對多線程的并發(fā)操作進行了處理，所以是線程安全的

2.以OC的方式封裝了SQLite的C語言API，使用起來更加方便

3.FMDB是輕量級框架使用靈活

缺點:

因為它是OC的語言封裝的，只能在ios開發(fā)的時候使用，所以在實現(xiàn)跨平臺操作的時候存在局限性。

FMDB框架中重要的框架類

FMDataBase

FMDataBase對象就代表一個單獨的SQLite數(shù)據(jù)庫用來執(zhí)行SQL語句

FMResultSet

使用FNDataBase執(zhí)行查詢后的結(jié)果集

FMDataBaseQueue

用于在多線程中執(zhí)行多個查詢或更新他是線程安全的

下面通過一個例子來講解FMDB的具體用法

首先使用FMDB需要導入libsqlite3.0框架，在需要數(shù)據(jù)庫的類中引入FMDatabase.h.``

創(chuàng)建數(shù)據(jù)庫

例子中用到的測試模型類

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@interface student : NSObject

@property (nonatomic,assign) int stuid;

@property (nonatomic,copy) NSString *name;

@property (nonatomic,copy) NSString *sex;

@property (nonatomic,assign) int age; @end</pre>

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創(chuàng)建數(shù)據(jù)庫的代碼

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<pre style="margin: 0px; white-space: pre-wrap; word-wrap: break-word; padding: 0px; list-style-type: none; list-style-image: none; font-family: "Courier New" !important; font-size: 12px !important;">- (void)createDataBase { //創(chuàng)建數(shù)據(jù)庫 //1>獲取數(shù)據(jù)庫文件的路徑
NSString *docpath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *fileName = [docpath stringByAppendingPathComponent:@"student.sqlite"]; //初始化數(shù)據(jù)庫
db = [[FMDatabase alloc] initWithPath:fileName]; //創(chuàng)建數(shù)據(jù)庫中的表
if (db) { if ([db open]) {
BOOL stuSql = [db executeUpdate:@"create table if not exists stu(stuid integer primary key autoincrement, name varchar(255),sex varchar(255),age integer)"]; if (stuSql) {
NSLog(@"數(shù)據(jù)庫創(chuàng)建表成功");
}else {
NSLog(@"創(chuàng)建表失敗");
}
}else {
NSLog(@"數(shù)據(jù)庫沒有打開");
}
}else {
NSLog(@"創(chuàng)建數(shù)據(jù)庫失敗");
}
}</pre>

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注意創(chuàng)建數(shù)據(jù)庫時路徑的問題路徑可以是以下三種方式之一

1.文件路徑該文件路徑真實存在，如果不存在回自動創(chuàng)建

2.空字符串@"" 表示會在臨時目錄里創(chuàng)建一個空的數(shù)據(jù)庫當FMDataBase連接關閉時文件也會被刪除

3.NULL 將創(chuàng)建一個內(nèi)在數(shù)據(jù)庫同樣的當FMDataBase連接關閉時數(shù)據(jù)將會被銷毀

向數(shù)據(jù)庫中添加數(shù)據(jù) 查找數(shù)據(jù) 和刪除數(shù)據(jù)

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(void)insertDataToDb{
NSArray *array = @[@"13141",@"13142",@"13143",@"13144",@"13145"]; for (int i = 0; i < 5; i ++) {
NSString *insertSql = @"insert into stu(stuid,name,sex,age) values(?,?,?,?)";
```
  BOOL success = [db executeUpdate:insertSql,array[i],[NSString stringWithFormat:@"tian%d",i],@"男",@20]; if (success) {
      NSLog(@"數(shù)據(jù)插入成功");
  }
```
}
} //查詢數(shù)據(jù)庫 //查詢所有的數(shù)據(jù)庫數(shù)據(jù)
(void)selectDataFormDb{
NSString *selectSql = @"select *from stu";
FMResultSet *result = [db executeQuery:selectSql]; while ([result next]) {
NSLog(@"%@ %@ %@ %d",[result stringForColumn:@"stuid"],[result stringForColumn:@"name"],[result stringForColumn:@"sex"],[result intForColumn:@"age"]);
}

} //清空數(shù)據(jù)庫

(void)deleteAllDbData {
NSString *deleteSql = @"delete from stu";
BOOL success = [db executeUpdate:deleteSql]; if (success) {
NSLog(@"刪除數(shù)據(jù)成功");
}
}</pre>

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清空數(shù)據(jù)庫之前的打印結(jié)果是

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修改數(shù)據(jù)

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(void)updateDbData { //tian6是新值代替數(shù)據(jù)庫中name = tian1的值
NSString *updateSql = @"update stu set name = ? where name = ?";
BOOL success = [db executeUpdate:updateSql,@"tian6",@"tian1"]; if (success) {
[self selectDataFormDb];
}
} //結(jié)果
2016-12-12 13:44:45.489 FMDB[1604:103750] 13141 tian0 男 20
2016-12-12 13:44:45.489 FMDB[1604:103750] 13142 tian6 男 20
2016-12-12 13:44:45.489 FMDB[1604:103750] 13143 tian2 男 20
2016-12-12 13:44:45.489 FMDB[1604:103750] 13144 tian3 男 20
2016-12-12 13:44:45.489 FMDB[1604:103750] 13145 tian4 男 20</pre>

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下面是另寫的一個完整的例子

student.h文件

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@interface Student : NSObject
@property(nonatomic,strong)NSStringstuid;
@property(nonatomic,strong)NSStringstuname;

@property(nonatomic,strong)NSString*stuage;
@property(nonatomic,strong)NSData * stuheadimage; @end</pre>

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studentManager.h文件

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import "Student.h"

@interface studentDBManager : NSObject +(instancetype)shareManager; //添加一條數(shù)據(jù)到數(shù)據(jù)表中
-(BOOL)addDataWithModel:(Student*)student ConditionString:(NSString *)conditionStr andconditionValue:(NSString *)conditionValue andtable:(NSString * )table; //通過某個字段刪除一條數(shù)據(jù)；
-(BOOL)deleteDataWithConditionString:(NSString *)conditionStr andconditionValue:(NSString *)conditionValue andtable:(NSString * )table; // 刪除所有的記錄

(BOOL)deleteAllDataWithtable:(NSString )table; //查詢一條數(shù)據(jù)； //1.查詢?nèi)繑?shù)據(jù)，2根據(jù)特定字段查詢數(shù)據(jù)；
-(NSArray * )getDataWithconditionString:(NSString * )conditionstr andConditionValue:(NSString )conditionValue allData:(BOOL)isAllData andTable:(NSString )table; //修改某條數(shù)據(jù)
-(BOOL)updateDataWithString:(NSString)NewStr andNewStrValue:(id)NewStrValue andConditionStr:(NSString)conditionStr andConditionValue:(NSString)conditionValue andTable:(NSString*)table; @end</pre>

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studentManager.m文件

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import "FMDB.h"

static studentDBManager * manager=nil; @implementation studentDBManager

{
FMDatabase * _database;
} +(instancetype)shareManager
{ static dispatch_once_t onceTocken;
dispatch_once(&onceTocken, ^{
manager=[[studentDBManager alloc]init];
}); return manager;
} -(instancetype)init
{ if (self=[super init]) { // 創(chuàng)建數(shù)據(jù)庫，使用FMDB第三方框架 // 創(chuàng)建數(shù)據(jù)庫文件保存路徑..../Documents/app.sqlite // sqlite數(shù)據(jù)庫（輕量級的數(shù)據(jù)庫），它就是一個普通的文件，txt是一樣的，只不過其中的文件內(nèi)容不一樣。 // 注：sqlite文件中定義了你的數(shù)據(jù)庫表、數(shù)據(jù)內(nèi)容 // MySql、Oracle這些大型的數(shù)據(jù)庫，它需要一個管理服務，是一整套的。
NSString * dbPath=[NSString stringWithFormat:@"%@/Documents/app.sqlite",NSHomeDirectory()];
NSLog(@"%@",dbPath); // 創(chuàng)建FMDatabase // 如果在目錄下沒有這個數(shù)據(jù)庫文件，將創(chuàng)建該文件。
_database=[[FMDatabase alloc]initWithPath:dbPath]; if (_database) { if ([_database open]) { //第一步：創(chuàng)建學生信息表
NSString *stuSql = @"create table if not exists stu(stuid varchar(255),name varchar(255),age varchar(255),headimage binary)"; //第一步：創(chuàng)建學生信息表
NSString * createSql=@"create table if not exists stu(stuid varchar(255),name varchar(255),age varchar(255),headimage binary)"; // FMDatabase執(zhí)行sql語句 // 當數(shù)據(jù)庫文件創(chuàng)建完成時，首先創(chuàng)建數(shù)據(jù)表，如果沒有這個表，就去創(chuàng)建，有了就不創(chuàng)建
BOOL creatableSucess=[_database executeUpdate:createSql];
NSLog(@"創(chuàng)建表%d",creatableSucess);

        } else {
            NSLog(@"打開數(shù)據(jù)庫失敗");
        }
    } else {
        NSLog(@"創(chuàng)建數(shù)據(jù)庫失敗");
    }
} return self;

} ////通過某個字段檢查是否存在數(shù)據(jù)

(BOOL)isExsitsWithConditionString:(NSString *)conditionStr andConditionValue:(NSString *)conditionValue andtable:(NSString *)table
{
NSString * querySql = [NSString stringWithFormat:@"select * from %@ where %@='%@'", table,conditionStr,conditionValue];

FMResultSet * set = [_database executeQuery:querySql]; // 判斷是否已存在數(shù)據(jù)
if ([set next]) { return YES;
} else
return NO;
} //添加一條數(shù)據(jù)到數(shù)據(jù)表中
-(BOOL)addDataWithModel:(Student*)student ConditionString:(NSString *)conditionStr andconditionValue:(NSString *)conditionValue andtable:(NSString * )table
{ // 如果已存在數(shù)據(jù)，先刪除已有的數(shù)據(jù)，再添加新數(shù)據(jù)
BOOL isExsits = [self isExsitsWithConditionString:conditionStr andConditionValue:conditionValue andtable:table]; if (isExsits) {
[self deleteDataWithConditionString:conditionStr andconditionValue:conditionValue andtable:table];
} // 添加新數(shù)據(jù)
NSString * insertSql = [NSString stringWithFormat:@"insert into %@ values (?,?,?,?)",table];

BOOL success = [_database executeUpdate:insertSql,student.stuid ,student.stuname,student.stuage,student.stuheadimage];
NSLog(@"%d",success); return success;
} //通過某個字段刪除一條數(shù)據(jù)；
-(BOOL)deleteDataWithConditionString:(NSString *)conditionStr andconditionValue:(NSString *)conditionValue andtable:(NSString * )table
{ //刪除之前先判斷該數(shù)據(jù)是否存在；
BOOL isExsits=[self isExsitsWithConditionString:conditionStr andConditionValue:conditionValue andtable:table]; if (isExsits) {
NSString * deleteSql = [NSString stringWithFormat:@"delete from %@ where %@='%@'",table,conditionStr,conditionValue];
BOOL success=[_database executeUpdate:deleteSql]; return success;
} else {
NSLog(@"該記錄不存在"); return NO;
}

} // 刪除所有的記錄

(BOOL)deleteAllDataWithtable:(NSString *)table
{
NSString * deletesql=[NSString stringWithFormat:@"delete from %@",table];

BOOL success = [_database executeUpdate:deletesql]; return success;

} //查詢一條數(shù)據(jù)； //1.查詢?nèi)繑?shù)據(jù)，2根據(jù)特定字段查詢數(shù)據(jù)；
-(NSArray * )getDataWithconditionString:(NSString * )conditionstr andConditionValue:(NSString *)conditionValue allData:(BOOL)isAllData andTable:(NSString *)table
{

NSString * getSql; if (isAllData) {
     getSql =[NSString stringWithFormat:@"select * from %@",table];
} else {
     getSql = [NSString stringWithFormat:@"select * from %@ where %@='%@'",table,conditionstr,conditionValue];
} // 執(zhí)行sql
FMResultSet * set = [_database executeQuery:getSql]; // 循環(huán)遍歷取出數(shù)據(jù)
NSMutableArray * array = [[NSMutableArray alloc] init]; while ([set next]) {
    Student * model = [[Student alloc] init]; // 從結(jié)果集中獲取數(shù)據(jù) // 注：sqlite數(shù)據(jù)庫不區(qū)別分大小寫
    model.stuid = [set stringForColumn:@"stuid"];
    model.stuname= [set stringForColumn:@"name"];
    model.stuage=[set stringForColumn:@"age"];
    model.stuheadimage=[set dataForColumn:@"headimage"];
    [array addObject:model];
} //備注：stuheadimage的使用，   UIImage * image=[UIImage imageWithData:imageData];
return array;

} //修改某條數(shù)據(jù)
-(BOOL)updateDataWithString:(NSString)NewStr andNewStrValue:(id)NewStrValue andConditionStr:(NSString)conditionStr andConditionValue:(NSString)conditionValue andTable:(NSString)table
{
NSString * updateSql=[NSString stringWithFormat:@"UPDATE %@ SET %@='%@' WHERE %@='%@';",table,NewStr,NewStrValue,conditionStr,conditionValue];
BOOL success= [_database executeUpdate:updateSql]; return success;
}</pre>

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數(shù)據(jù)庫的多線程操作

如果應用中使用了多線程操作數(shù)據(jù)庫，那么就需要使用FMDatabaseQueue來保證線程安全了。應用中不可在多個線程中共同使用一個FMDatabase對象操作數(shù)據(jù)庫，這樣會引起數(shù)據(jù)庫數(shù)據(jù)混亂。為了多線程操作數(shù)據(jù)庫安全，F(xiàn)MDB使用了FMDatabaseQueue，使用FMDatabaseQueue很簡單，首先用一個數(shù)據(jù)庫文件地址來初使化FMDatabaseQueue，然后就可以將一個閉包(block)傳入inDatabase方法中。在閉包中操作數(shù)據(jù)庫，而不直接參與FMDatabase的管理。

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<pre style="margin: 0px; white-space: pre-wrap; word-wrap: break-word; padding: 0px; list-style-type: none; list-style-image: none; font-family: "Courier New" !important; font-size: 12px !important;"> FMDatabaseQueue * queue = [FMDatabaseQueue databaseQueueWithPath:database_path];
dispatch_queue_t q1 = dispatch_queue_create("queue1", NULL);
dispatch_queue_t q2 = dispatch_queue_create("queue2", NULL);

   dispatch_async(q1, ^{ for (int i = 0; i < 50; ++i) {  
           [queue inDatabase:^(FMDatabase *db2) {  

               NSString *insertSql1= [NSString stringWithFormat: @"INSERT INTO '%@' ('%@', '%@', '%@') VALUES (?, ?, ?)",  
                                      TABLENAME, NAME, AGE, ADDRESS];  

               NSString * name = [NSString stringWithFormat:@"jack %d", i];  
               NSString * age = [NSString stringWithFormat:@"%d", 10+i];  

               BOOL res = [db2 executeUpdate:insertSql1, name, age,@"濟南"]; if (!res) {  
                   NSLog(@"error to inster data: %@", name);  
               } else {  
                   NSLog(@"succ to inster data: %@", name);  
               }  
           }];  
       }  
   });  

   dispatch_async(q2, ^{ for (int i = 0; i < 50; ++i) {  
           [queue inDatabase:^(FMDatabase *db2) {  
               NSString *insertSql2= [NSString stringWithFormat: @"INSERT INTO '%@' ('%@', '%@', '%@') VALUES (?, ?, ?)",  
                                      TABLENAME, NAME, AGE, ADDRESS];  

               NSString * name = [NSString stringWithFormat:@"lilei %d", i];  
               NSString * age = [NSString stringWithFormat:@"%d", 10+i];  

               BOOL res = [db2 executeUpdate:insertSql2, name, age,@"北京"]; if (!res) {  
                   NSLog(@"error to inster data: %@", name);  
               } else {  
                   NSLog(@"succ to inster data: %@", name);  
               }  
           }];  
       }  
   }); </pre>

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上面就是iOS中FMDB數(shù)據(jù)庫框架的一些基本應用.

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iOS本地存儲-數(shù)據(jù)庫(FMDB)

iOS本地存儲-數(shù)據(jù)庫(FMDB)

FMDB PK Sqlite

import "Student.h"

import "FMDB.h"

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友情鏈接更多精彩內(nèi)容

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iOS本地存儲-數(shù)據(jù)庫(FMDB)

FMDB PK Sqlite

import "Student.h"

import "FMDB.h"

相關閱讀更多精彩內(nèi)容

友情鏈接更多精彩內(nèi)容

色偷偷精品伊人,欧洲久久精品,欧美综合婷婷骚逼,国产AV主播,国产最新探花在线,九色在线视频一区,伊人大交九欧美,1769亚洲,黄色成人av