| 标题 | IOS之数据库的查找，删除，添加，更新 |
| 内容 | DB类之.h文件 #import <Foundation/Foundation.h> #import <sqlite3.h> @interface DB : NSObject +(sqlite3 *)openDB;//打开数据库 -(void)closeDB;//关闭数据库 @end DB类之.m文件 #import "DB.h" #import <sqlite3.h> static sqlite3 *db = nil; @implementation DB +(sqlite3 *)openDB { if(db) { return db; } //目标路径 NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDirectory, YES)objectAtIndex:0]; //原始路径 NSString *filePath = [docPath stringByAppendingPathComponent:@"db.sqlite"]; NSFileManager *fm = [NSFileManager defaultManager]; if ([fm fileExistsAtPath:filePath] == NO)//如果doc下没有数据库，从bundle里面拷贝过来 { NSString *bundle = [[NSBundle mainBundle]pathForResource:@"classDB" ofType:@"sqlite"]; NSError *err = nil; if ([fm copyItemAtPath:bundle toPath:filePath error:&err] == NO) //如果拷贝失败 { NSLog(@" localizedDescription]); } } sqlite3_open([filePath UTF8String], &db); return db; } -(void)closeDB { if (db) { sqlite3_close(db); } } @end Person类.h文件 #import <Foundation/Foundation.h> @interface Person : NSObject @property(nonatomic,retain)NSString *name,*phone; @property(nonatomic,assign)int age,ID; -(id)initWithName:(NSString *)name phone:(NSString *)phone age:(int)age ID:(int)ID; +(NSMutableArray *)findAll; +(int)count; +(Person *)findByID:(int)ID; +(NSMutableArray *)findByname:(NSString *)name; +(void)addName:(NSString *)name phone:(NSString *)phone age:(int)age; +(void)deleteByID:(int)ID; +(void)updataName:(NSString *)name phone:(NSString *)phone age:(int)age forID:(int)ID; @end Person类.m文件 #import "Person.h" #import "DB.h" @implementation Person @synthesize name,ID,phone,age; -(id)initWithName:(NSString *)aName phone:(NSString *)aPhone age:(int)aAge ID:(int)aID { [super init]; if (self) { self.name = aName; self.phone = aPhone; self.age = aAge; self.ID = aID; } return self; } -(NSString *)description { return [NSString stringWithFormat:@"id = %d name = %@ phone = %@ age = %d",self.ID,self.name,self.phone,self.age ]; } +(NSMutableArray *)findAll { sqlite3 *db = [DB openDB]; sqlite3_stmt *stmt = nil;//创建一个声明对象 int result = sqlite3_prepare_v2(db, "select * from classDB order by ID ", -1, &stmt, nil); NSMutableArray *persons = nil; if (result == SQLITE_OK) { persons = [[NSMutableArray alloc]init]; while (sqlite3_step(stmt) == SQLITE_ROW) { int ID = sqlite3_column_int(stmt, 0); const unsigned char *name = sqlite3_column_text(stmt, 1); const unsigned char *phone = sqlite3_column_text(stmt, 2); int age = sqlite3_column_int(stmt, 3); Person *p = [[Person alloc]initWithName:[NSString stringWithUTF8String:(const char *)name] phone:[NSString stringWithUTF8String:(const char *)phone] age:age ID:ID]; [persons addObject:p]; [p release]; } } else { persons = [[NSMutableArray alloc]init]; } sqlite3_finalize(stmt); return [persons autorelease]; } +(int)count { sqlite3 *db = [DB openDB]; sqlite3_stmt *stmt = nil; int result = sqlite3_prepare_v2(db, "select count(ID) from classDB", -1, &stmt, nil); if (result == SQLITE_OK) { int count = 0; if (sqlite3_step(stmt)) { count = sqlite3_column_int(stmt, 0); } sqlite3_finalize(stmt); return count; } else { sqlite3_finalize(stmt); return 0; } } +(Person *)findByID:(int)ID { sqlite3 *db = [DB openDB]; sqlite3_stmt *stmt = nil; Person *p = nil; int result = sqlite3_prepare_v2(db, "select * from classDB where ID = ?", -1, &stmt, nil); if (result == SQLITE_OK) { sqlite3_bind_int(stmt, 1, ID); if (sqlite3_step(stmt)) { int ID = sqlite3_column_int(stmt, 0); const unsigned char *name = sqlite3_column_text(stmt, 1); const unsigned char *phone = sqlite3_column_text(stmt, 2); int age = sqlite3_column_int(stmt, 3); p = [[Person alloc]initWithName:[NSString stringWithUTF8String:(const char *)name] phone:[NSString stringWithUTF8String:(const char *)phone] age:age ID:ID]; } } sqlite3_finalize(stmt); return [p autorelease]; } +(NSMutableArray *)findByname:(NSString *)name { sqlite3 *db = [DB openDB]; sqlite3_stmt *stmt = nil; int result = sqlite3_prepare(db, "select * from classDB where name = ?", -1, &stmt, nil); NSMutableArray *persons = nil; if (result == SQLITE_OK) { sqlite3_bind_text(stmt, 1, [name UTF8String], -1, nil); persons = [[NSMutableArray alloc]init]; while (sqlite3_step(stmt) == SQLITE_ROW) { int ID = sqlite3_column_int(stmt, 0); const unsigned char *name = sqlite3_column_text(stmt, 1); const unsigned char *phone = sqlite3_column_text(stmt, 2); int age = sqlite3_column_int(stmt, 3); Person *p = [[Person alloc]initWithName:[NSString stringWithUTF8String:(const char *)name] phone:[NSString stringWithUTF8String:(const char *)phone] age:age ID:ID]; [persons addObject:p]; [p release]; } } else { persons = [[NSMutableArray alloc]init]; } sqlite3_finalize(stmt); return [persons autorelease]; } //添加元素 +(void)addName:(NSString *)name phone:(NSString *)phone age:(int)age { NSString *str = [NSString stringWithFormat:@"insert into classDB(name,phone,age) values(]; sqlite3 *db = [DB openDB]; sqlite3_stmt *stmt = nil; int result = sqlite3_prepare_v2(db, [str UTF8String],-1 ,&stmt , nil); if (result == SQLITE_OK) { sqlite3_step(stmt); } sqlite3_finalize(stmt); } //根据ID删除信息 +(void)deleteByID:(int)ID { NSString *str = [NSString stringWithFormat:@"delete from classDB where ID = %d",ID]; sqlite3 *db = [DB openDB]; sqlite3_stmt *stmt = nil; int result = sqlite3_prepare_v2(db, [str UTF8String], -1, &stmt, nil); if (result == SQLITE_OK) { sqlite3_step(stmt); } sqlite3_finalize(stmt); } //更新 +(void)updataName:(NSString *)name phone:(NSString *)phone age:(int)age forID:(int)ID { NSString *str = [NSString stringWithFormat:@"update classDB set name = = %d where ID = %d",name,phone,age,ID]; sqlite3 *db = [DB openDB]; sqlite3_stmt *stmt = nil; int result = sqlite3_prepare_v2(db, [str UTF8String], -1, &stmt, nil); if (result == SQLITE_OK) { sqlite3_step(stmt); } sqlite3_finalize(stmt); } @end |
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