//sqlite的基本使用-Prefix.pch
1.
//
// Prefix header
// The contents of this file are implicitly included at the beginning of every source file.
//
#ifdef __OBJC__
#import <Foundation/Foundation.h>
#endif
// Prefix header
//
// The contents of this file are implicitly included at the beginning of every source file.
//
#import <Availability.h>
#ifndef __IPHONE_5_0
#warning "This project uses features only available in iOS SDK 5.0 and later."
#endif
#ifdef __OBJC__
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#endif
#import <Foundation/Foundation.h>
int main(int argc,const char * argv[])
{
@autoreleasepool {
NSMutableString *sql = [NSMutableString string];
NSArray *names = @[@"jack", @"rose",@"jim", @"jake"];
for (int i = 0; i<100; i++) {
int index = arc4random()%names.count;
NSString *namePre = names[index];
NSString *name = [NSString stringWithFormat:@"%@-%d",namePre,arc4random()%100];
int age = arc4random() % 100;
double score = arc4random() % 100;
[sql appendFormat:@"insert into t_student (name,age,score) values('%@',%d,%f);\n",name,score];
}
///Users/mc/Desktop/素材images
///Users/aplle/Desktop/student.sql
[sql writeToFile:@"Users/mc/Desktop/student.sql" atomically:YES encoding:NSUTF8StringEncoding error:nil];
}
return 0;
}
*****************************
#import <Foundation/Foundation.h>
int main(int argc,const char * argv[])
{
@autoreleasepool {
NSArray *names = @[@"西门抽血",@"西门抽筋",@"西门抽风",@"西门吹雪"];
NSMutableString *sql = [NSMutableString string];
for (int i = 0; i<200; i++) {
int ID = i + 1;
int age = arc4random_uniform(20) + 20;
NSString *name = names[arc4random_uniform(names.count)];
name = [name stringByAppendingFormat:@"-%d",arc4random_uniform(100)];
[sql appendFormat:@"insert into t_student (id,age) values (%d,'%@',%d);\n",ID,age];
}
[sql writeToFile:@"/Users/apple/Desktop/students.sql" atomically:YES encoding:NSUTF8StringEncoding error:nil];
NSLog(@"\n%@",sql);
}
return 0;
}
#import<sqlite3.h>
@interfaceIWViewController()
{
sqlite3*_db;// db代表着整个数据库，db是数据库实例
}
- (IBAction)insert;
- (IBAction)update;
- (IBAction)delete;
- (IBAction)query;
@end
@implementationIWViewController
- (void)viewDidLoad
{
[superviewDidLoad];
NSString*filename = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMaskYES)lastObject]stringByAppendingPathComponent:@"student.sqlite" // 1.创建(打开)数据库（如果数据库文件不存在，会自动创建）
intresult =sqlite3_open(filename.UTF8String,&_db);
if(result ==sqlITE_OK) {
NSLog(@"成功打开数据库");
// 2.创表
constchar*sql ="create table if not exists t_student (id integer primary key autoincrement,name text,age integer);";
char*errorMesg =NULL;
sqlite3_exec(_db,sql,NULL,&errorMesg);
sqlITE_OK) {
NSLog(@"成功创建t_student表");
}else{
创建t_student表失败:%s",errorMesg);
}
}else{
打开数据库失败");
}
}
- (IBAction)insert
{
for(inti =0; i<30; i++) {
NSString*name = [NSStringstringWithFormat:@"Jack-%d",arc4random()%100];
intage =100;
*sql = [stringWithFormat:@"insert into t_student (name,age) values('%@',%d);"
sql.sqlITE_OK) {
成功添加数据");
}添加数据失败 }
}
}
- (IBAction)update
{
}
- (IBAction)delete
{
}
- (IBAction)query
{
// sql注入漏洞
/**
1.用户输入账号和密码
*账号：123' or 1 = 1 or '' = '
*密码：456654679
2.拿到用户输入的账号和密码去数据库查询（查询有没有这个用户名和密码）
select * from t_user where username = '123' and password = '456';
*/
// 1.定义sql语句
*sql ="select id,age from t_student where name = ?;";
// 2.定义一个stmt存放结果集
sqlite3_stmt*stmt =NULL;
// 3.检测sql语句的合法性
sqlite3_prepare_v2(1,&stmt,162)">NULL);
查询语句是合法的");
//设置占位符的内容
sqlite3_bind_text(stmt,"jack",162)">NULL);
// 4.执行sql语句，从结果集中取出数据
// int stepResult = sqlite3_step(stmt);
while(sqlite3_step(stmt) ==sqlITE_ROW) {//真的查询到一行数据
获得这行对应的数据
获得第0列的id
intsid =sqlite3_column_int(stmt,216)">0);
//获得第1列的name
constunsignedchar*sname =sqlite3_column_text(stmt,216)">1);
2age
intsage =2);
@"%d %s %d",sid,sname,sage);
}
}查询语句非合法");
}
}
@end
2.*************************
#import "ViewController.h"
#import <sqlite3.h>
@interface ViewController ()
- (IBAction)insert;
- (IBAction)update;
- (IBAction)delete;
- (IBAction)select;
// db就是数据库的象征，如果要进行CRUD，得操作db这个实例
@property (nonatomic,assign) sqlite3 *db;
@end
@implementation HMViewController
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *doc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES) lastObject];
NSString *filename = [doc stringByAppendingPathComponent:@"students.sqlite"];
// 将OC字符串 转成 C语言字符串
const char *cfilename = filename.UTF8String;
// 1.打开数据库（如果数据库文件不存在，sqlite3_open函数会自动创建数据库文件）
int result = sqlite3_open(cfilename,&_db);
if (result == sqlITE_OK) { // 打开成功
NSLog(@"成功打开数据库");
// 2. const char *sql = "CREATE TABLE IF NOT EXISTS t_student (id integer PRIMARY KEY AUTOINCREMENT,name text NOT NULL,age integer NOT NULL);";
char *erroMsg = NULL;
result = sqlite3_exec(self.db,NULL,&erroMsg);
if (result == sqlITE_OK) {
NSLog(@"成功创表");
} else {
// printf("创表失败--%s--%s-%d",erroMsg,__FILE__,__LINE__);
NSLog(@"创表失败--%s--%@-%d",[NSString stringWithUTF8String:__FILE__],__LINE__);
}
} else {
NSLog(@"打开数据库失败");
}
}
- (IBAction)insert {
for (int i = 0; i<20; i++) {
// 1.拼接sql语句
NSString *name = [NSString stringWithFormat:@"Jack-%d",arc4random_uniform(100)];
int age = arc4random_uniform(20) + 30;
NSString *sql = [NSString stringWithFormat:@"INSERT INTO t_student (name,age) VALUES ('%@',%d);",age];
// 2.执行sql语句
char *erroMsg = NULL;
sqlite3_exec(self.db,sql.UTF8String,&erroMsg);
if (erroMsg) {
NSLog(@"插入数据失败--%s",erroMsg);
} else {
NSLog(@"成功插入数据");
}
}
}
- (IBAction)update {
}
- (IBAction)delete {
}
- (IBAction)select {
const char *sql = "SELECT id,age FROM t_student WHERE age <= 30;";
// 进行查询前的准备工作
// sqlite3_stmt：用来取数据
sqlite3_stmt *stmt = NULL;
if (sqlite3_prepare_v2(self.db,-1,NULL) == sqlITE_OK) { // sql语句没有问题
NSLog(@"查询语句没有问题");
// 每调一次sqlite3_step函数，stmt就会指向下一条记录
while (sqlite3_step(stmt) == sqlITE_ROW) { // 找到一条记录
// 取出数据
// 取出第0列字段的值（int类型的值）
int ID = sqlite3_column_int(stmt,0);
// 取出第1列字段的值（tex类型的值）
const unsigned char *name = sqlite3_column_text(stmt,1);
// 取出第2列字段的值（int类型的值）
int age = sqlite3_column_int(stmt,2);
NSLog(@"%d %s %d",age);
}
} else {
NSLog(@"查询语句有问题");
}
}
@end
原文链接：https://www.f2er.com/sqlite/199442.html