標籤:io ar os 使用 sp for strong 檔案 資料
嵌入式資料庫
SQLite嵌入式資料庫優點
1.支援事件,不需要配置,不需要安裝,不需要管理員
2.支援發部分SQL92
3.完整的資料庫儲存在磁碟上面一個檔案,同一個資料庫檔案可以在不同機器上面使用,最大支援資料庫到2T
4.整個系統少於3萬行,少於250KB的記憶體佔用
Linux系統級的SQLite技術實現架構libsqlite3.0.dylib
開始使用SQLite
1.引入<sqlite3.h>標頭檔
2.開啟資料庫
3.執行SQL命令
4.關閉資料庫
一下代碼展示整個資料庫的 開啟,關閉,增加,刪除,尋找,修改,
建立一個單例
#import <Foundation/Foundation.h>@class Student;@interface DataBaseHandle : NSObject//建立一個單例+(DataBaseHandle *)shareDB;//擷取Documents路徑- (NSString *)documentsPath;//開啟資料庫- (void)openDB;//關閉資料庫- (void)closeDB;//建立表- (void)createTable;//插入資訊- (void)insertStudent:(Student *)stu;//修改資訊- (void)updateMessage;//刪除資訊- (void)deleteMessage;//尋找全部- (void)selectAllStudent;//條件尋找- (void)selectWithSex:(NSString *)sex;@end
#import "DataBaseHandle.h"#import <sqlite3.h>#import "Student.h"//全域單利對象static DataBaseHandle *shareModle = nil;@implementation DataBaseHandle#pragma mark 實現單利+ (DataBaseHandle *)shareDB{ if (nil == shareModle) { shareModle = [[DataBaseHandle alloc] init]; } return shareModle;}#pragma mark 擷取Documents路徑- (NSString *)documentsPath{ NSString *documentPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0]; return documentPath;}//在操作資料之前引入架構(sql...3.0)//聲明一個資料庫的對象static sqlite3 *db = nil;#pragma mark 開啟資料庫- (void)openDB{ //判斷資料庫是不是為空白 if (nil == db) { //與documents路徑拼接資料庫存放路徑(獲得存放路徑) NSString *dbPath = [[self documentsPath] stringByAppendingString:@"/Student.sqlite"]; //根據路徑開啟資料庫,如該路徑下沒有資料庫,就自動建立一個資料庫 //開啟資料庫(c語言中的文法) int result = sqlite3_open(dbPath.UTF8String, &db); //判斷是否開啟資料庫成功 if (result == SQLITE_OK) { NSLog(@"資料庫開啟成功"); } else { NSLog(@"資料庫開啟失敗"); } }}#pragma mark 關閉資料庫- (void)closeDB{ int result = sqlite3_close(db); if (result == SQLITE_OK) { //如果關閉成功,置為nill db = nil; NSLog(@"資料庫關閉成功"); } else { NSLog(@"資料庫關閉失敗"); }}#pragma mark 建立表- (void)createTable{ //要建立表,就要使用SQL語句. //SQL語句在這是以字串的形式存在的 NSString *createString = @"CREATE TABLE IF NOT EXISTS student (sid INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL , sname TEXT, ssex TEXT, sage TEXT)"; //執行SQL語句 int result = sqlite3_exec(db, createString.UTF8String, NULL, NULL, NULL); if (result == SQLITE_OK) { NSLog(@"建立表成功"); } else { NSLog(@"建立失敗"); } }#pragma mark 插入資訊- (void)insertStudent:(Student *)stu{ //準備插入語句 NSString *insertString = [NSString stringWithFormat:@"INSERT INTO student (sname,ssex,sage) VALUES ('%@','%@','%@')",stu.name,stu.sex,stu.age]; //執行語句 int result = sqlite3_exec(db, insertString.UTF8String, NULL, NULL, NULL); if (result == SQLITE_OK) { NSLog(@"插入成功"); } else { NSLog(@"插入失敗"); } }#pragma mark 修改資料- (void)updateMessage{ //準備修改語句 NSString *undataString = @"UPDATE student SET ssex = '女' ,sname = '小夢' WHERE sid = 10"; int result = sqlite3_exec(db, undataString.UTF8String, NULL, NULL, NULL); if (result == SQLITE_OK) { NSLog(@"修改成功"); } else { NSLog(@"修改失敗"); } }#pragma mark 刪除資料- (void)deleteMessage{ //準備刪除語句 NSString *deleteString = @"DELETE FROM student WHERE sid = 1"; int result = sqlite3_exec(db, deleteString.UTF8String, NULL, NULL, NULL); if (result == SQLITE_OK) { NSLog(@"delete OK"); } else { NSLog(@"delete _NO"); } }#pragma mark 尋找全部- (void)selectAllStudent{ //準備尋找語句 NSString *selectAll = @"SELECT *FROM student"; //建立伴隨指標 sqlite3_stmt *stmt = nil; //預備執行 int result = sqlite3_prepare(db, selectAll.UTF8String, -1, &stmt, NULL); if (result == SQLITE_OK) { //在沒有尋找完成之前一直迴圈執行 while (sqlite3_step(stmt) == SQLITE_ROW) { //取出sid(第0列) NSInteger sid = sqlite3_column_int(stmt, 0); //取出sname(第1列) NSString *sname = [NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 1)]; //取出ssex(第2列) NSString *ssex = [NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 2)]; //取出sage(第3列) NSString *sage = [NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 3)]; NSLog(@"sid:%d sname:%@ ssex:%@ sage:%@",sid,sname,ssex,sage); } sqlite3_finalize(stmt); } else { //如果尋找失敗,結束伴隨指標 sqlite3_finalize(stmt); NSLog(@"尋找失敗"); } }#pragma mark 條件尋找- (void)selectWithSex:(NSString *)sex{ //準備尋找語句 NSString *selecstString = @"SELECT * FROM student WHERE ssex = ?"; //建立伴隨指標 sqlite3_stmt *stmt = nil; //預執行 int result = sqlite3_prepare(db, selecstString.UTF8String, -1, &stmt, NULL); if (result == SQLITE_OK) { //綁定?的值 //"1"代表第一個問號"?"和哪個參數綁定 sqlite3_bind_text(stmt, 1, sex.UTF8String, -1, NULL); while (sqlite3_step(stmt) == SQLITE_ROW) { NSInteger sid = sqlite3_column_int(stmt, 0); NSString *sname = [NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 1)]; NSString *ssex = [NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 2)]; NSString *sage = [NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 3)]; NSLog(@"sid: %d sname: %@ ssex: %@ sage: %@",sid,sname,ssex,sage); } } else { //關閉指標 sqlite3_finalize(stmt); NSLog(@"查詢失敗"); }}@end
建立一個Student類
#import <Foundation/Foundation.h>@interface Student : NSObject@property(nonatomic,strong)NSString *name;@property(nonatomic,strong)NSString *age;@property(nonatomic,strong)NSString *sex;@end
在 ViewController.m中 ViewDidLoad 調用方法
//列印路徑 NSLog(@"%@",[[DataBaseHandle shareDB] documentsPath]); //開啟資料庫 [[DataBaseHandle shareDB] openDB]; //建立表 [[DataBaseHandle shareDB] createTable]; //插入資訊// Student *stu = [[Student alloc] init];// stu.name = @"小露";// stu.age = @"29";// stu.sex = @"女";// [[DataBaseHandle shareDB] insertStudent:stu]; //修改// [[DataBaseHandle shareDB] updateMessage]; //刪除// [[DataBaseHandle shareDB] deleteMessage]; //尋找全部資訊// [[DataBaseHandle shareDB] selectAllStudent]; //根據條件尋找資訊 [[DataBaseHandle shareDB] selectWithSex:@"女"];
IOS 資料庫管理系統(SQLite)