1. 首先要先導(dǎo)入第三方類庫(kù)FMdatabase。  
2. 獲得存放數(shù)據(jù)庫(kù)文件的沙盒地址。 

       +(NSString*)databaseFilePath  
   
   [objc] view plaincopy
   
           {  
             
           NSArray*filePath=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);  
           NSString*documentPath=[filePathobjectAtIndex:0];  
           NSLog(@"%@",filePath);  
           NSString*dbFilePath=[documentPathstringByAppendingPathComponent:@"db.sqlite"];  
           returndbFilePath;  
             
           }  
       3、創(chuàng)建數(shù)據(jù)庫(kù)的操作  
         
       +(void)creatDatabase  
           {  
           db=[[FMDatabasedatabaseWithPath:[selfdatabaseFilePath]]retain];  
           }  
       4、創(chuàng)建表  
         
       +(void)creatTable  
           {  
           //先判斷數(shù)據(jù)庫(kù)是否存在，如果不存在，創(chuàng)建數(shù)據(jù)庫(kù)  
           if(!db){  
           [selfcreatDatabase];  
           }  
           //判斷數(shù)據(jù)庫(kù)是否已經(jīng)打開，如果沒(méi)有打開，提示失敗  
           if(![dbopen]){  
           NSLog(@"數(shù)據(jù)庫(kù)打開失敗");  
           return;  
           }  
             
           //為數(shù)據(jù)庫(kù)設(shè)置緩存，提高查詢效率  
           [dbsetShouldCacheStatements:YES];  
             
           //判斷數(shù)據(jù)庫(kù)中是否已經(jīng)存在這個(gè)表，如果不存在則創(chuàng)建該表  
           if(![dbtableExists:@"people"])  
           {  
           [dbexecuteUpdate:@"CREATETABLES people(people_id INTEGER PRIMARY KEY AUTOINCREAMENT, nameTEXT, age INTEGER) "];  
             
             
           NSLog(@"創(chuàng)建完成");  
           }  
             
           }  
       5、增加表數(shù)據(jù)  
         
       +(void)insertPeople:(People*)aPeople  
           {  
           if(!db){  
           [selfcreatDatabase];  
           }  
             
           if(![dbopen]){  
           NSLog(@"數(shù)據(jù)庫(kù)打開失敗");  
           return;  
           }  
             
           [dbsetShouldCacheStatements:YES];  
             
           if(![dbtableExists:@"people"])  
           {  
           [selfcreatTable];  
           }  
           //以上操作與創(chuàng)建表是做的判斷邏輯相同  
           //現(xiàn)在表中查詢有沒(méi)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(shù)據(jù)庫(kù)中插入一條數(shù)據(jù)  
           else{  
           [dbexecuteUpdate:@"INSERTINTO people (name, age) VALUES(?,?)",aPeople.name,[NSStringstringWithFormat:@"%d",aPeople.age]];  
           }  
             
           }  
       6、刪除數(shù)據(jù)  
         
       +(void)deletePeopleByID:(int)ID  
           {  
           if(!db){  
           [selfcreatDatabase];  
           }  
             
           if(![dbopen]){  
           NSLog(@"數(shù)據(jù)庫(kù)打開失敗");  
           return;  
           }  
             
           [dbsetShouldCacheStatements:YES];  
             
           //判斷表中是否有指定的數(shù)據(jù)， 如果沒(méi)有則無(wú)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(shù)據(jù)庫(kù)打開失敗");  
           returnnil;  
           }  
             
           [dbsetShouldCacheStatements:YES];  
             
           if(![dbtableExists:@"people"])  
           {  
           returnnil;  
           }  
             
           //定義一個(gè)可變數(shù)組，用來(lái)存放查詢的結(jié)果，返回給調(diào)用者  
           NSMutableArray*peopleArray=[[NSMutableArrayalloc]initWithArray:0];  
           //定義一個(gè)結(jié)果集，存放查詢的數(shù)據(jù)  
           FMResultSet*rs=[dbexecuteQuery:@"select* from people"];  
           //判斷結(jié)果集中是否有數(shù)據(jù)，如果有則取出數(shù)據(jù)  
           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(shù)據(jù)放入數(shù)組中。  
           [peopleArrayaddObject:aPeople];  
           }  
           return[peopleArrayautorelease];  
           }  
       8、查詢  
         
       +(NSArray*)getAllPeople  
           {  
             
           if(!db){  
           [selfcreatDatabase];  
           }  
             
           if(![dbopen]){  
           NSLog(@"數(shù)據(jù)庫(kù)打開失敗");  
           returnnil;  
           }  
             
           [dbsetShouldCacheStatements:YES];  
             
           if(![dbtableExists:@"people"])  
           {  
           returnnil;  
           }  
             
           //定義一個(gè)可變數(shù)組，用來(lái)存放查詢的結(jié)果，返回給調(diào)用者  
           NSMutableArray*peopleArray=[[NSMutableArrayalloc]initWithArray:0];  
           //定義一個(gè)結(jié)果集，存放查詢的數(shù)據(jù)  
           FMResultSet*rs=[dbexecuteQuery:@"select* from people"];  
           //判斷結(jié)果集中是否有數(shù)據(jù)，如果有則取出數(shù)據(jù)  
           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(shù)據(jù)放入數(shù)組中。  
           [peopleArrayaddObject:aPeople];  
           }  
           return[peopleArrayautorelease];  
           }  

   
   
   

標(biāo)簽： 數(shù)據(jù)庫(kù)

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