| 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 |
| 随便看 |
|
在线学习网考试资料包含高考、自考、专升本考试、人事考试、公务员考试、大学生村官考试、特岗教师招聘考试、事业单位招聘考试、企业人才招聘、银行招聘、教师招聘、农村信用社招聘、各类资格证书考试等各类考试资料。