iOS 原生sqlite3的使用方法
本文介紹了iOS 原生sqlite3的使用方法,分享給大家,具體如下:
SQLite?
- SQLit是一個開源、輕型嵌入式關(guān)系數(shù)據(jù)庫,誕生于2000年5月
- 占用資源非常的低,在嵌入式設備中,可能只需要幾百K的內(nèi)存就夠了
- 能夠支持Windows/Linux/Unix等等主流的操作系統(tǒng)
- 比起Mysql、PostgreSQL這兩款開源的世界著名數(shù)據(jù)庫管理系統(tǒng)來講,它的處理速度比他們都快
SQL語句常用操作
增、刪、改、查,CRUD,Create[新建], Retrieve[檢索], Update[更新], Delete[刪除]。
SQL語法寫法特點
1、不區(qū)分大小寫(CREATE = create)
2、每條語句以分號(;)結(jié)尾
3、關(guān)鍵字建議大寫
SQL語句常用關(guān)鍵字
select、insert、update、delete、from、create、where、desc、order、by、group、table、alter、view、index等
- 數(shù)據(jù)定義語句(DDL):包括create和drop等操作,在數(shù)據(jù)庫中創(chuàng)建新表或刪除表(create table或 drop table)
- 數(shù)據(jù)操作語句(DML):包括insert、update、delete等操作,分別用于添加、修改、刪除表中的數(shù)據(jù)
- 數(shù)據(jù)查詢語句(DQL):可以用于查詢獲得表中的數(shù)據(jù),關(guān)鍵字select是DQL(也是所有SQL)用得最多的操作,其他DQL常用的關(guān)鍵字有where,order by,group by和having
// 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 查詢
- (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) {
//遍歷查詢結(jié)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(@"查詢語句完成");
}
} else {
NSLog(@"查詢語句不合法");
}
sqlite3_finalize(statement);
[self closeDB];
}
#pragma mark 刪除數(shù)據(jù)記錄
- (void)deleteData{
sqlite3 *newDB = [self openDB];
sqlite3_stmt *statement = nil;
NSString *sqlStr = @"DELETE FROM SAAS_PERSON WHERE NAME = '王鵬飛'";
int result = sqlite3_prepare_v2(newDB, sqlStr.UTF8String, -1, &statement, NULL);
if (result == SQLITE_OK) {
if (sqlite3_step(statement) == SQLITE_DONE) {
NSLog(@"刪除操作完成");
}
} else {
NSLog(@"刪除操作不合法");
}
sqlite3_finalize(statement);
[self closeDB];
}
#pragma mark 更新數(shù)據(jù)記錄
- (void)updateData{
sqlite3 *newDB = [self openDB];
sqlite3_stmt *statement = nil;
NSString *sqlStr = @"UPDATE SAAS_PERSON SET DESCRIPTION = '喜歡運動,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拼寫錯誤) --- 更新信息不合法
NSLog(@"更新信息不合法");
}
sqlite3_finalize(statement);
[self closeDB];
}
#pragma mark 新增數(shù)據(jù)記錄
- (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,'開朗樂觀')";
// NSString *sqlStr = @"INSERT INTO SAAS_PERSON (NAME , SEX , AGE , DESCRIPTION) VALUES('王鵬飛','女',27,'開朗樂觀')";
// NSString *sqlStr = @"INSERT INTO SAAS_PERSON (NAME , SEX , AGE , DESCRIPTION) VALUES('李梅','女',20,'年輕可愛��')";
NSString *sqlStr = @"INSERT INTO SAAS_PERSON (NAME , SEX , AGE , DESCRIPTION) VALUES('sumit','男',15,'小朋友的年紀')";
//檢驗合法性
int result = sqlite3_prepare_v2(newDB, sqlStr.UTF8String, -1, &statement, NULL);
if (result == SQLITE_OK) {
//判斷語句執(zhí)行完畢
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 創(chuàng)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(@"創(chuàng)建表成功");
} else {
NSLog(@"創(chuàng)建表失敗 = %s",error);
}
[self closeDB];
}
#pragma mark 刪除表
- (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(@"刪除表成功");
} else {
NSLog(@"刪除表失敗 = %s",error);
}
[self closeDB];
}
#pragma mark 打開或者創(chuàng)建數(shù)據(jù)庫
- (sqlite3 *)openDB {
if (!db) {
//1.獲取document文件夾的路徑
//參數(shù)1:文件夾的名字 參數(shù)2:查找域 參數(shù)3:是否使用絕對路徑
NSString *documentPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];
//獲取數(shù)據(jù)庫文件的路徑
NSString *dbPath = [documentPath stringByAppendingPathComponent:@"saas.sqlite"];
NSLog(@"%@",dbPath);
//判斷document中是否有sqlite文件
int result = sqlite3_open([dbPath UTF8String], &db);
if (result == SQLITE_OK) {
NSLog(@"打開數(shù)據(jù)庫");
}else{
[self closeDB];
NSLog(@"打開數(shù)據(jù)庫失敗");
}
}
return db;
}
#pragma mark 關(guān)閉數(shù)據(jù)庫
- (void)closeDB{
int result = sqlite3_close(db);
if (result == SQLITE_OK) {
NSLog(@"數(shù)據(jù)庫關(guān)閉成功");
db = nil;
} else {
NSLog(@"數(shù)據(jù)庫關(guān)閉失敗");
}
}
@end
以上就是本文的全部內(nèi)容,希望對大家的學習有所幫助,也希望大家多多支持腳本之家。
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