#import "databasehandle.h"
#import@interface databasehandle ()
/**用来存放数据库的路径 */
@property(nonatomic,strong)NSString *filepath;
@end
static databasehandle *dataBse =nil;
@implementation databasehandle
/**数据库指针 */
static sqlite3 *DB =nil;
//懒加载lazy loading (只有被调用的时候才会被赋值)全局只要使用了一次self,那么在其他地方_方式也有只.但是一般来说都用self来调用懒加载.懒加载内部实现中最好不要出现self;
-(NSString *)filepath{
if (!_filepath) {
_filepath =[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).lastObject stringByAppendingPathComponent:@"student.sqlite"];
}return _filepath;
}
//单利
+(instancetype)sharedDataBase{
if (!dataBse) {
dataBse =[[databasehandle alloc]init];
}return dataBse;
}
//创建表
-(void)createTable{
//1.准备sql语句
NSString *sqlString =@"create table if not exists person(name text,age integet)";
//2.执行sql语句
int result =sqlite3_exec(DB, sqlString.UTF8String, NULL, NULL, NULL);
if (result ==SQLITE_OK) {
NSLog(@"键表成功");
}else{
NSLog(@"键表失败%d",result);
}
}
-(void)OpenDB{
/**数据库存放的地址*/
NSLog(@"%@",self.filepath);
int result =sqlite3_open(self.filepath.UTF8String, &DB);
if (result ==SQLITE_OK) {
NSLog(@"打开成功");
}else{
NSLog(@"打开失败%d",result);
}
}
-(void)closeDB{
int result =sqlite3_close(DB);
if (result==SQLITE_OK) {
NSLog(@"关闭成功");
}else{
NSLog(@"失败");
NSLog(@"%d",result);
}
}
-(void)insertStudemtWithName:(NSString *)name age:(NSInteger)age{
//1.准备sql语句
NSString *sqlstring =@"insert into person(name,age)values(?,?)";
//2.创建伴随指针(用来绑定参数,和获取数据)
sqlite3_stmt *stmt =NULL;
//3.预执行
int result =sqlite3_prepare(DB, sqlstring.UTF8String, -1, &stmt, NULL);
if (result==SQLITE_OK) {
//4.参数绑定
//第二个参数代表的是第几个字段,从1开始计数
sqlite3_bind_text(stmt, 1, name.UTF8String, -1, NULL);
sqlite3_bind_int64(stmt, 2, age);
//5.执行
if (sqlite3_step(stmt)==SQLITE_DONE) {
NSLog(@"插入成功");
}else{
NSLog(@"插入失败%d",result);
}
}else{
NSLog(@"语句错误%d",result);
}
//关闭伴随指针
sqlite3_finalize(stmt);
}
//该(updata)
-(void)updataWithage:(NSInteger)age{
//1.准备 sql语句
NSString *sqlstring =@"updata Student set age =20 where age =?";
//2.创建伴随指针
sqlite3_stmt *stmt =NULL;
//3.预执行
int result =sqlite3_prepare(DB, sqlstring.UTF8String, -1, &stmt, NULL);
if (result ==SQLITE_OK) {
sqlite3_bind_int64(stmt, 1, age);
if (sqlite3_step(stmt)==SQLITE_DONE) {
NSLog(@"跟新成功");
}else{
NSLog(@"跟新失败");
}
}else{
NSLog(@"语法错误");
}
sqlite3_finalize(stmt);
}
-(void)selectWithName:(NSString *)name{
//1.准备sql语句
NSString *sqlstring =@"select name,age from Student where name =?";
//伴随指针
sqlite3_stmt *stmt =NULL;
int result =sqlite3_prepare(DB, sqlstring.UTF8String, -1, &stmt, NULL);
if (result ==SQLITE_OK) {
sqlite3_bind_text(stmt, 1, name.UTF8String, -1, NULL);
while (sqlite3_step(stmt)==SQLITE_ROW) {
NSString *readname =[NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 0)];
NSInteger readage =sqlite3_column_int64(stmt, 1);
NSLog(@"姓名%@ 年龄%ld",readname ,readage);
}
}else{
NSLog(@"查询出错");
}
//6.关闭伴随指针
sqlite3_finalize(stmt);
}
-(void)deletepersonwithage:(NSInteger)age{
NSString *sqlstring =[NSString stringWithFormat:@"delete from person where age =%ld",age];
int result =sqlite3_exec(DB, sqlstring.UTF8String, NULL
, NULL, NULL);
if (result ==SQLITE_OK) {
NSLog(@"shanchu cehnggong");
}else{
NSLog(@"shibaishanchu");
}
}
