1 数据库打开

+ (instancetype)shareDataBaseHandler{

//单例创建
static HPZDataHandle *hdHandler = nil;
if(hdHandler == nil){
    hdHandler = [[HPZDataHandle alloc] init];
}
return hdHandler;
}

创建一个sqlite3 对象
sqlite3 *hd;

    if (hd) {
        NSLog(@"数据库已打开");
        return;
    }
    NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject] stringByAppendingPathComponent:@"huliji.sqlite"];
    NSLog(@"%@",path);
    int result = sqlite3_open(path.UTF8String, &hd);
    if (result == SQLITE_OK) {
        NSLog(@"数据库打开成功");
    }else{
        NSLog(@"数据库打开失败,错误码:%d",result);
    }```

#2 基本语句

1.创建表
```sqlite
"CREATE TABLE IF NOT EXISTS Hunliji (Cate INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT,image TEXT)"

2.插入数据

NSString *sql = [NSString stringWithFormat:@"INSERT INTO Hunliji(title,image) VALUES('%@','%@')",model.title,model.cover_path];

3.更新数据

NSString *sql = [NSString stringWithFormat:@"UPDATE Hunliji SET title = '%@',image = '%@' WHERE title = '%@'",model.title,model.cover_path,title];

4.删除数据

NSString *sql = [NSString stringWithFormat:@"UPDATE Hunliji SET title = '%@',image = '%@' WHERE title = '%@'",model.title,model.cover_path,title];

5.查询表

    NSMutableArray *arr = [NSMutableArray array];
    //查找sql语句
    NSString *sql = [NSString stringWithFormat:@"select *from Hunliji"];
    
    //创建一个 准备好的语句对象
    sqlite3_stmt *stmt = nil;
    //为准备好的语句对象赋值(SQL语句内容)
    int result = sqlite3_prepare_v2(hd, sql.UTF8String, -1, &stmt, nil);
    if (result == SQLITE_OK) {
        NSLog(@"开始查询");
        
        while (sqlite3_step(stmt) == SQLITE_ROW) {
            //查询条件匹配,使用sqlite3_column函数簇  将需要的列值取出来
            const unsigned char *title = sqlite3_column_text(stmt, 1);
            const unsigned char *image = sqlite3_column_text(stmt, 2);
            //model赋值
            HPZModelOfEntity *model = [[HPZModelOfEntity alloc] init];
            model.title = [NSString stringWithUTF8String:(const char*) title];
            model.cover_path = [NSString stringWithUTF8String:(const char*) image];
            [arr addObject:model];

结果返回一个存放查询到数据的数组

6.删除表

DROP TABLE Hunliji