iOS 原生sqlite3的使用方法

// ViewController.m
// sqlite3
//
// Created by 周玉 on 2017/12/13.
// Copyright © 2017年 guidekj. All rights reserved.
//
#import "ViewController.h"
#import <sqlite3.h>
#define KUIScreenWidth [UIScreen mainScreen].bounds.size.width
#define KUIScreenHeight [UIScreen mainScreen].bounds.size.height
#define FILE_NAME @"saas.sqlite"
static sqlite3 *db = nil;
@interface ViewController ()
@end

@implementation ViewController

- (void)viewDidLoad {
  [super viewDidLoad];
  self.title = @"sqlite3";

  //DDB
//  [self openDB];
//  [self closeDB];

  //DDL
//  [self createTable];
//  [self dropTable];

  //DML
//  [self insertData];
//  [self updateData];
//  [self deleteData];

  //DQL
  [self queryData];
}

#pragma mark 查询
- (void)queryData{
  sqlite3 *newDB = [self openDB];
  sqlite3_stmt *statement = nil;
  NSString *sqlStr = @"SELECT * FROM SAAS_PERSON";
  int result = sqlite3_prepare_v2(newDB, sqlStr.UTF8String, -1, &statement, NULL);
  if (result == SQLITE_OK) {
    //遍历查询结果
    if (!(sqlite3_step(statement) == SQLITE_DONE)) {
      while (sqlite3_step(statement) == SQLITE_ROW) {
        int ID = sqlite3_column_int(statement, 0);
        const unsigned char *name = sqlite3_column_text(statement, 1);
        const unsigned char *sex = sqlite3_column_text(statement, 2);
        int age = sqlite3_column_int(statement, 3);
        const unsigned char *description = sqlite3_column_text(statement, 4);
        NSLog(@"ID = %d , name = %@ , sex = %@ , age = %d , description = %@",ID,[NSString stringWithUTF8String:(const char *)name],[NSString stringWithUTF8String:(const char *)sex],age,[NSString stringWithUTF8String:(const char *)description]);
      }
    } else {
      NSLog(@"查询语句完成");
    }
  } else {
    NSLog(@"查询语句不合法");
  }
  sqlite3_finalize(statement);
  [self closeDB];
}

#pragma mark 删除数据记录
- (void)deleteData{
  sqlite3 *newDB = [self openDB];
  sqlite3_stmt *statement = nil;
  NSString *sqlStr = @"DELETE FROM SAAS_PERSON WHERE NAME = '王鹏飞'";
  int result = sqlite3_prepare_v2(newDB, sqlStr.UTF8String, -1, &statement, NULL);
  if (result == SQLITE_OK) {
    if (sqlite3_step(statement) == SQLITE_DONE) {
      NSLog(@"删除操作完成");
    }
  } else {
    NSLog(@"删除操作不合法");
  }
  sqlite3_finalize(statement);
  [self closeDB];
}

#pragma mark 更新数据记录
- (void)updateData{
  sqlite3 *newDB = [self openDB];
  sqlite3_stmt *statement = nil;
  NSString *sqlStr = @"UPDATE SAAS_PERSON SET DESCRIPTION = '喜欢运动,旅游' WHERE NAME = '周玉'";
  int result = sqlite3_prepare_v2(newDB, sqlStr.UTF8String, -1, &statement, NULL);
  if (result == SQLITE_OK) {
    if (sqlite3_step(statement) == SQLITE_DONE) {
      NSLog(@"更新信息完成");
    }
  } else {
    //[logging] no such column: DESCRIPT (KEY拼写错误) --- 更新信息不合法
    NSLog(@"更新信息不合法");
  }
  sqlite3_finalize(statement);
  [self closeDB];
}

#pragma mark 新增数据记录
- (void)insertData{
  sqlite3 *newDB = [self openDB];
  sqlite3_stmt *statement = nil;
//  NSString *sqlStr = @"INSERT INTO SAAS_PERSON (NAME , SEX , AGE , DESCRIPTION) VALUES('周玉','男',28,'开朗乐观')";
//  NSString *sqlStr = @"INSERT INTO SAAS_PERSON (NAME , SEX , AGE , DESCRIPTION) VALUES('王鹏飞','女',27,'开朗乐观')";
//  NSString *sqlStr = @"INSERT INTO SAAS_PERSON (NAME , SEX , AGE , DESCRIPTION) VALUES('李梅','女',20,'年轻可爱��')";
  NSString *sqlStr = @"INSERT INTO SAAS_PERSON (NAME , SEX , AGE , DESCRIPTION) VALUES('sumit','男',15,'小朋友的年纪')";
  //检验合法性
  int result = sqlite3_prepare_v2(newDB, sqlStr.UTF8String, -1, &statement, NULL);
  if (result == SQLITE_OK) {
    //判断语句执行完毕
    if (sqlite3_step(statement) == SQLITE_DONE) {
      NSLog(@"插入的信息完成");
    }
  } else {
    NSLog(@"插入的信息不合法");
  }
  sqlite3_finalize(statement);
  [self closeDB];
}

#pragma mark 创建表
- (void)createTable{
  sqlite3 *newDB = [self openDB];
  //  char *sql = "CREATE TABLE IF NOT EXISTS t_person (ID INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, NAME TEXT , SEX TEXT,AGE INTEGER,DESCRIPTION TEXT);";
  NSString *sqlStr = @"CREATE TABLE IF NOT EXISTS SAAS_PERSON (ID INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, NAME TEXT , SEX TEXT,AGE INTEGER,DESCRIPTION TEXT);";
  char *error = NULL;

  int result = sqlite3_exec(newDB, sqlStr.UTF8String, NULL, NULL, &error);
  if (result == SQLITE_OK) {
    NSLog(@"创建表成功");
  } else {
    NSLog(@"创建表失败 = %s",error);
  }
  [self closeDB];
}

#pragma mark 删除表
- (void)dropTable{
  sqlite3 *newDB = [self openDB];
  NSString *sqlStr = @"DROP TABLE t_person";
  char *error = NULL;
  int result = sqlite3_exec(newDB, sqlStr.UTF8String, NULL, NULL, &error);
  if (result == SQLITE_OK) {
    NSLog(@"删除表成功");
  } else {
    NSLog(@"删除表失败 = %s",error);
  }
  [self closeDB];
}

#pragma mark 打开或者创建数据库
- (sqlite3 *)openDB {
  if (!db) {
    //1.获取document文件夹的路径
    //参数1:文件夹的名字 参数2:查找域 参数3:是否使用绝对路径
    NSString *documentPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];
    //获取数据库文件的路径
    NSString *dbPath = [documentPath stringByAppendingPathComponent:@"saas.sqlite"];
    NSLog(@"%@",dbPath);
    //判断document中是否有sqlite文件
    int result = sqlite3_open([dbPath UTF8String], &db);
    if (result == SQLITE_OK) {
      NSLog(@"打开数据库");

    }else{
      [self closeDB];
      NSLog(@"打开数据库失败");
    }
  }
  return db;
}

#pragma mark 关闭数据库
- (void)closeDB{
  int result = sqlite3_close(db);
  if (result == SQLITE_OK) {
    NSLog(@"数据库关闭成功");
    db = nil;
  } else {
    NSLog(@"数据库关闭失败");
  }
}
@end