利用周六时间看了一下关于sqlite的知识。在这记录一下。看的传智播客视频

对数据的操作基本上就是增删改查：

static sqlite3 *db; //声明一个数据库

@implementation XSDBOperator

+ (void)initialize

{

    NSString *filename = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]stringByAppendingPathComponent:@"student.sqlite"];  //数据库文件路径

    //假设文件存在，则打开数据库文件。假设不存在则创建，而且打开

    int result = sqlite3_open(filename.UTF8String, &db); //

    //推断是否打开数据库成功

    if (result == SQLITE_OK) {

        NSLog(@"打开数据库成功");

    }

    else

    {

        NSLog(@"打开失败");

    }

}

#pragma mark - 创建数据库表

+(BOOL)creatTable

{

    char *sql = "create table if not exists t_student (id integer primary key autoincrement,name text,age integer,score integer);";

    char *errorMesg = NULL;

    int result = sqlite3_exec(db, sql, NULL, NULL, &errorMesg);//用于操作数据库

    if (result == SQLITE_OK) {

        return YES;

    }

    else

    {

        NSLog(@"创建表失败,失败原因:%s",errorMesg);

        return NO;

    }

}

+(BOOL)insert

{

    char *sql = "insert into t_table (name,age) values('jack',20)";

    char *errorMesg = NULL;

    int result = sqlite3_exec(db, sql , NULL, NULL, &errorMesg);

    if (result == SQLITE_OK) {

        return YES;

    }

    else

    {

        NSLog(@"插入数据失败,失败原因:%s",errorMesg);

        return NO;

    }

}

+ (BOOL)updata

{

    char *sql = "updata t_table set age = 12";

    char *errorMesg = NULL;

    int result = sqlite3_exec(db, sql , NULL, NULL, &errorMesg);

    if (result == SQLITE_OK) {

        return YES;

    }

    else

    {

        NSLog(@"更新数据失败,失败原因:%s",errorMesg);

        return NO;

    }

}

+ (void)query

{

    char *sql = "select id,name,age from t_student;";

    //查询结果保存集合

    sqlite3_stmt *stmt= NULL;

    int result = sqlite3_prepare_v2(db, sql , -1, &stmt, NULL);

    if (result == SQLITE_OK) {

        NSLog(@"查询语句合法");

        while (sqlite3_step(stmt) == SQLITE_ROW) { //依照行进行遍历 直到取完为止

            int sid = sqlite3_column_int(stmt, 0); //取当前行出第几列的值

            const unsigned char *sname = sqlite3_column_text(stmt, 1);

            int sage = sqlite3_column_int(stmt, 2);

            NSLog(@"%d,%s,%d",sid,sname,sage);

        }

    }

    else

    {

        NSLog(@"查询语句不合法");

    }

}

@end