数据库sqlite的使用

#import <Foundation/Foundation.h>

@class student;

@interface DataBaseHandle : NSObject

//设置单例

+(DataBaseHandle *)shareDB;

//获取沙盒document路径

-(NSString *)documentPath;

//打开数据库

-(void)openDB;

//关闭数据库

-(void)closeDB;

//创建表

-(void)createTable;

//插入信息

-(void)insertStudent:(student *)stu;

//修改信息

-(void)updateMessage;

//删除信息

-(void)deleteMessage;

//查找全部

-(void)selectAllStudent;

//条件查找(按性别查找)

-(void)selectwithSex:(NSString *)sex;

*****************************************************

#import "DataBaseHandle.h"

#import <sqlite3.h>

#import "student.h"

//全局单例对象

static DataBaseHandle *database=nil;

@implementation DataBaseHandle

#pragma mark  实现单例

+(DataBaseHandle *)shareDB

{

if (nil==database) {

database=[[DataBaseHandle alloc] init];

}

return database;

}

//获取document路径

-(NSString *)documentPath

{

return NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];

}

//使用数据库步骤

//1.在操作数据库之前引入框架

//2.声明一个数据库对象

static sqlite3 *db=nil;

//打开数据库

-(void)openDB

{

if (nil==db) {

//拼接数据库存放路径

NSString *dbPath=[[self documentPath] stringByAppendingString:@"/student.sqlite"];

//根据路径打开数据库

//如果该路径下没有数据库,就自动创建一个

//打开数据库

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

//判断师傅成功

if (result==SQLITE_OK) {

NSLog(@"打开成功");

}

else

{

NSLog(@"打开失败");

}

}

}

#pragma mark 创建表

-(void)createTable

{

//要创建表就要使用SQl语句

///SQL语句在这十一字符串形式存在的

NSString *createString=@"CREATE TABLE   IF NOT EXISTS student (sid INTEGER PRIMARY KEY  AUTOINCREMENT  NOT NULL , sname TEXT, ssex TEXT, sage TEXT)";

//执行SQL语句

int result=sqlite3_exec(db, createString.UTF8String, NULL, NULL, NULL);

if (result==SQLITE_OK) {

NSLog(@"创建成功");

}

else

{

NSLog(@"创建失败");

}

}

#pragma mark 插入信息

-(void)insertStudent:(student *)stu

{

//准备插入语句

NSString *insertString=[NSString stringWithFormat:@"INSERT INTO student (sname,ssex,sage) VALUES ('%@','%@','%@')",stu.name,stu.sex,stu.age];

//执行语句

int result=sqlite3_exec(db, insertString.UTF8String, NULL, NULL, NULL);

if (result==SQLITE_OK) {

NSLog(@"插入成功");

}

else

{

NSLog(@"插入失败");

}

}

#pragma mark 修改数据

-(void)updateMessage

{

NSString *updateString=@"UPDATE student SET sid = '1' WHERE  sid = 6";

int result=sqlite3_exec(db, updateString.UTF8String, NULL, NULL, NULL);

if (result==SQLITE_OK) {

NSLog(@"修改成功");

}

else

{

NSLog(@"修改失败");

}

}

#pragma mark 删除数据

-(void)deleteMessage

{

NSString *deleteString=@"delete from student where sid=5";

int result=sqlite3_exec(db, deleteString.UTF8String, NULL, NULL, NULL);

if (result==SQLITE_OK) {

NSLog(@"删除成功");

}

else

{

NSLog(@"删除失败");

}

}

#pragma  mark 查找

-(void)selectAllStudent

{

//准备查找语句

NSString *selectAll=@"select * from student";

//创建伴随指针

sqlite3_stmt *stmt=nil;

//预备执行

int result=sqlite3_prepare(db, selectAll.UTF8String, -1, &stmt, NULL);

if (result==SQLITE_OK) {

//在没有查找完之前一直循环执行

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);

}

//关闭伴随指针

sqlite3_finalize(stmt);

}

else

{

//结束伴随指针

sqlite3_finalize(stmt);

NSLog(@"查找失败");

}

}

#pragma mark 性别查找

-(void)selectwithSex:(NSString *)sex

{

//准备查找语句

NSString *selectString=@"select * from student where ssex=? ";

//伴随指针

sqlite3_stmt *stmt=nil;

//预执行

int result=sqlite3_prepare(db, selectString.UTF8String, -1, &stmt, nil);

if (result==SQLITE_OK) {

//绑定?的值

//'1'代表第一个?和参数绑定

sqlite3_bind_text(stmt, 1, sex.UTF8String, -1, NULL);

while (sqlite3_step(stmt)==SQLITE_ROW) {

//取出sid(第0列)

NSInteger sid=sqlite3_column_int(stmt, 0);

//取出姓名(第一列)

NSString *sname=[NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 1)];

//取出性别(第二列)

NSString *ssex=[NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 2)];

//取出年龄(第三列)

NSString *sage=[NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, 3)];

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

}

//结束伴随指针

sqlite3_finalize(stmt);

}

else

{

//关闭查询指针

sqlite3_finalize(stmt);

NSLog(@"查询失败");

}

}