iOS 使用FMDB進行數據庫操作

    +(NSString*)databaseFilePath  

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        {  

        NSArray*filePath=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);  
        NSString*documentPath=[filePathobjectAtIndex:0];  
        NSLog(@"%@",filePath);  
        NSString*dbFilePath=[documentPathstringByAppendingPathComponent:@"db.sqlite"];  
        returndbFilePath;  

        }  
    3、創建數據庫的操作  

    +(void)creatDatabase  
        {  
        db=[[FMDatabasedatabaseWithPath:[selfdatabaseFilePath]]retain];  
        }  
    4、創建表  

    +(void)creatTable  
        {  
        //先判斷數據庫是否存在，如果不存在，創建數據庫  
        if(!db){  
        [selfcreatDatabase];  
        }  
        //判斷數據庫是否已經打開，如果沒有打開，提示失敗  
        if(![dbopen]){  
        NSLog(@"數據庫打開失敗");  
        return;  
        }  

        //為數據庫設置緩存，提高查詢效率  
        [dbsetShouldCacheStatements:YES];  

        //判斷數據庫中是否已經存在這個表，如果不存在則創建該表  
        if(![dbtableExists:@"people"])  
        {  
        [dbexecuteUpdate:@"CREATETABLES people(people_id INTEGER PRIMARY KEY AUTOINCREAMENT, nameTEXT, age INTEGER) "];  


        NSLog(@"創建完成");  
        }  

        }  
    5、增加表數據  

    +(void)insertPeople:(People*)aPeople  
        {  
        if(!db){  
        [selfcreatDatabase];  
        }  

        if(![dbopen]){  
        NSLog(@"數據庫打開失敗");  
        return;  
        }  

        [dbsetShouldCacheStatements:YES];  

        if(![dbtableExists:@"people"])  
        {  
        [selfcreatTable];  
        }  
        //以上操作與創建表是做的判斷邏輯相同  
        //現在表中查詢有沒有相同的元素，如果有，做修改操作  
        FMResultSet*rs=[dbexecuteQuery:@"select* from people where people_id = ?",[NSStringstringWithFormat:@"%d",aPeople.peopleID]];  
        if([rsnext])  
        {  
        NSLog(@"dddddslsdkien");  
        [dbexecuteUpdate:@"updatepeople set name = ?, age = ? where people_id =1",aPeople.name,[NSStringstringWithFormat:@"%d",aPeople.age]];  
        }  
        //向數據庫中插入一條數據  
        else{  
        [dbexecuteUpdate:@"INSERTINTO people (name, age) VALUES(?,?)",aPeople.name,[NSStringstringWithFormat:@"%d",aPeople.age]];  
        }  

        }  
    6、刪除數據  

    +(void)deletePeopleByID:(int)ID  
        {  
        if(!db){  
        [selfcreatDatabase];  
        }  

        if(![dbopen]){  
        NSLog(@"數據庫打開失敗");  
        return;  
        }  

        [dbsetShouldCacheStatements:YES];  

        //判斷表中是否有指定的數據， 如果沒有則無刪除的必要，直接return  
        if(![dbtableExists:@"people"])  
        {  
        return;  
        }  
        //刪除操作  
        [dbexecuteUpdate:@"deletefrom people where people_id = ?", [NSStringstringWithFormat:@"%d",ID]];  

        [dbclose];  
        }  
    7、修改操作與增加操作的步驟一致  

    +(NSArray*)getAllPeople  
        {  

        if(!db){  
        [selfcreatDatabase];  
        }  

        if(![dbopen]){  
        NSLog(@"數據庫打開失敗");  
        returnnil;  
        }  

        [dbsetShouldCacheStatements:YES];  

        if(![dbtableExists:@"people"])  
        {  
        returnnil;  
        }  

        //定義一個可變數組，用來存放查詢的結果，返回給調用者  
        NSMutableArray*peopleArray=[[NSMutableArrayalloc]initWithArray:0];  
        //定義一個結果集，存放查詢的數據  
        FMResultSet*rs=[dbexecuteQuery:@"select* from people"];  
        //判斷結果集中是否有數據，如果有則取出數據  
        while([rsnext]){  
        People*aPeople=[[Peoplealloc]init];  

        aPeople.peopleID=[rsintForColumn:@"people_id"];  
        aPeople.name=[rsstringForColumn:@"name"];  
        aPeople.age=[rsintForColumn:@"age"];  
        //將查詢到的數據放入數組中。  
        [peopleArrayaddObject:aPeople];  
        }  
        return[peopleArrayautorelease];  
        }  
    8、查詢  

    +(NSArray*)getAllPeople  
        {  

        if(!db){  
        [selfcreatDatabase];  
        }  

        if(![dbopen]){  
        NSLog(@"數據庫打開失敗");  
        returnnil;  
        }  

        [dbsetShouldCacheStatements:YES];  

        if(![dbtableExists:@"people"])  
        {  
        returnnil;  
        }  

        //定義一個可變數組，用來存放查詢的結果，返回給調用者  
        NSMutableArray*peopleArray=[[NSMutableArrayalloc]initWithArray:0];  
        //定義一個結果集，存放查詢的數據  
        FMResultSet*rs=[dbexecuteQuery:@"select* from people"];  
        //判斷結果集中是否有數據，如果有則取出數據  
        while([rsnext]){  
        People*aPeople=[[Peoplealloc]init];  

        aPeople.peopleID=[rsintForColumn:@"people_id"];  
        aPeople.name=[rsstringForColumn:@"name"];  
        aPeople.age=[rsintForColumn:@"age"];  
        //將查詢到的數據放入數組中。  
        [peopleArrayaddObject:aPeople];  
        }  
        return[peopleArrayautorelease];  
        }