本文主要是介绍第四十二篇:IOS 的 sqlite3 一些基本使用,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
一、sqlite3 使用操作
前提:在项目中导入 libsqlite3.0.tdb 数据库。
1.sqlite3 相关一些基本函数用法:
1.1、打开数据库
SQLITE_API int sqlite3_open(constchar *filename, /* Database filename (UTF-8) */sqlite3 **ppDb /* OUT: SQLite db handle */
);
该函数传的两个参数如下使用,例:
static sqlite3 * db ;
NSString * dataBaseFile = [dataBaseHandledataBaseFile];
int result = sqlite3_open([dataBaseFileUTF8String], &db);
if (result == SQLITE_OK) //说明已经打开数据库;
1.2、当数据库被打开后执行创建数据库表:
SQLITE_API int sqlite3_exec(sqlite3*, /* An open database */constchar *sql, /* SQL to be evaluated */int (*callback)(void*,int,char**,char**), /* Callback function */void *, /* 1st argument to callback */char **errmsg /* Error msg written here */
);
// 创建数据库表语句 , primary key autoincrement修饰主键在表中值是唯一存在(最后一个单词自动增加)
// 条件:
// 1.表中必须要有一个主键;
// 2.在插入数据时主键自动增加使用 autoincrement修饰;
// 3.主键的值在表中是唯一的,如果插入的数据主键值一样则不能添加在表内
NSString * sqliteStr = @"create table if not exists StudentList(stu_number integer primary key autoincrement,stu_name text,stu_gender text,stu_age integer)";
// 执行语句
sqlite3_exec(db, [sqliteStrUTF8String], NULL,NULL, NULL);
1.3、关闭数据库
int result = sqlite3_close(db);
NSLog(@"%@",result ==SQLITE_OK ? @"关闭成功":@"关闭失败");
1.4、插入数据相关几个函数
1.4.1、验证数据库语句,nByte 传 -1 时自动计算 zSql 数据库语句长度
SQLITE_API int sqlite3_prepare_v2(sqlite3 *db, /* Database handle */constchar *zSql, /* SQL statement, UTF-8 encoded */int nByte, /* Maximum length of zSql in bytes. */sqlite3_stmt **ppStmt, /* OUT: Statement handle */constchar **pzTail /* OUT: Pointer to unused portion of zSql */
);
1.4.2、数据库管理指针 sqlite3_stmt 类型
typedef structsqlite3_stmt sqlite3_stmt;
1.4.3、绑定数据
// 第二个参数表示 数据库语句中的第 k 个 "?" ,从 k>=1 。
SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,constchar*,int,void(*)(void*));
SQLITE_API int sqlite3_bind_int(sqlite3_stmt*,int, int);
SQLITE_API int sqlite3_bind_double(sqlite3_stmt*,int, double);
...............
如 sql 语句:
@"select * from StudentList where stu_number = ? and stu_name = ?"
// 绑定参数据如下:
// 帮定参数,在之前先省去了一些步骤,稍后看例子。
sqlite3_bind_int(stmt, 1, (int)number);
sqlite3_bind_text(stmt, 2, [@"李四"UTF8String], -1,NULL);
1.4.4、执行数据库语句
SQLITE_API int sqlite3_step(sqlite3_stmt*);
1.4.5、释放数据库管理指针
SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
插入数据示例:
// 插入数据
-(void)insertDataWithKeyValues:(StudentEntity *)entity
{// 1.打开数据库[self openDataBase];// 2.插入语句NSString * sqlStr = @"insert into StudentList(stu_name,stu_gender,stu_age,stu_number)values(?,?,?,?)";// 3.创建数据管理指针sqlite3_stmt * stmt = nil ;// 4.验证数据库语句,int result = sqlite3_prepare_v2(db, [sqlStr UTF8String], -1, &stmt, NULL);if (result == SQLITE_OK) {NSLog(@"可以插入数据");// 5.帮定数据// 参数:数据库管理指针 , 在 sqlStr 的第n个 ?, 数据库语句 , 语句长度(-1表示自动计算长度) ,sqlite3_bind_text(stmt, 1, [entity.name UTF8String], -1, NULL);sqlite3_bind_text(stmt, 2, [entity.gender UTF8String], -1, NULL);sqlite3_bind_int(stmt, 3, (int)entity.age);sqlite3_bind_int(stmt, 4, (int)entity.number);// 6.让 sql 语句执行sqlite3_step(stmt);}// 7.释放sqlite3_finalize(stmt);// 8.关闭数据库[self closeDataBase];
}
1.5、从数据库中取出每条数据的每一列对应的数据
// iCol 表示每个字段所在的列位置,从 0 开始。
SQLITE_API double sqlite3_column_double(sqlite3_stmt*,int iCol);
SQLITE_API int sqlite3_column_int(sqlite3_stmt*,int iCol);
SQLITE_API constunsigned char *sqlite3_column_text(sqlite3_stmt*,int iCol);
..................
1.6、数据库操作语句
ListName 为创建的表名,one 、two 和 three 都是表中每一列的字段。
// 创建数据库表
@"create table if not exists ListName(one text primary key autoincrement , two text , three integer,......)";// 插入数据
@"insert into ListName(one , two , three,....) values(? , ? , ? , ....) ";// 查询
@"select * from ListName" // 查询表中所有数据
@"select * from ListName where one = ? " //带有一个条件的查询
@"select * from ListName where one = ? and two = ?" // 满足一个条件的查询
@"select * from ListName where one = ? or three = ?" // 满足其中任意一个条件的查询
@"select * from ListName where three > ?" // 表中满足 three > 当前绑定的值 的 数据
@"select one,three from ListName where two = ? order by three disc(或是 asce)" // 查询表中满足(two = 当前绑定的值)条件的 one 和 three 值,并以 three 大小降序排列返回
@"select * from ListName where three > ? limit 5" // 满足条件的5条数据
@"select * from ListName where three > ? limit 3,5" // 跳过前三条数据 接着取后5条
@"select one,two from ListName where ...... " //选出满足条件数据条的 one 和 two 值// 模糊查询所有字段 two 包含 likeName 内容的数据都找出来
[NSString stringWithFormat:@"select * from ListName where two like '%%%@%%'",likeName];// 修改数据
@"update ListName set one = ? where three >= ?"// 删除数据
@"delete from ListName" // 删除表中所有数据
@"delete from ListName where one = ?" // 删除表中满足条件的数据// 删除整张表
@"drop table ListName"
2. 把 c 的字符串转换成 OC 中的 NSString 类型
[NSStringstringWithUTF8String:(char *)sqlite3_column_text(stmt,1)]
3.整个项目代码
3.1数据模型文件代码
//
// StudentEntity.h
// DataBaseDome
//
// Created by 瞿杰 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//#import <Foundation/Foundation.h>@interface StudentEntity : NSObject@property(nonatomic,assign)NSInteger number;
@property(nonatomic,copy)NSString *name;
@property(nonatomic,copy)NSString *gender;
@property(nonatomic,assign)NSInteger age;@end
//
// StudentEntity.m
// DataBaseDome
//
// Created by 瞿杰 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//#import "StudentEntity.h"@implementation StudentEntity@end
3.2 数据库操作文件
//
// DataBaseHandle.h
// DataBaseDome
//
// Created by 瞿杰 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//#import <Foundation/Foundation.h>@class StudentEntity ;@interface DataBaseHandle : NSObject+(instancetype)dataBaseHandleWithDataBaseName:(NSString *)dataBaseName;// 打开数据库
-(void)openDataBase ;
// 关闭数据库
-(void)closeDataBase ;// 插入数据
-(void)insertDataWithKeyValues:(StudentEntity *)entity ;// 更新
-(void)updateStudentGender:(NSString *)gender byNumber:(NSInteger)number ;// 查询
// 查询所有数据
-(NSArray<StudentEntity *> *)selectAllKeyValues ;// 根据条件查询
-(StudentEntity *)selectOneStudentByNumber:(NSInteger)number ;// 模糊查询,只要包含 likeName 内容
-(StudentEntity *)selectOneStudentLikeName:(NSString *)likeName ;// 删除表中数据
-(void)deleteOneStudentByNumber:(NSInteger)number ;// 删除表
-(void)dropTable;@end
//
// DataBaseHandle.m
// DataBaseDome
//
// Created by 瞿杰 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//#import "DataBaseHandle.h"#import "StudentEntity.h"
#import <sqlite3.h>@interface DataBaseHandle ()@property (nonatomic , copy)NSString * dataBaseName ;@end@implementation DataBaseHandlestatic sqlite3 * db ;+(instancetype)dataBaseHandleWithDataBaseName:(NSString *)dataBaseName
{DataBaseHandle * dataBaseHandle = [[self alloc] init];dataBaseHandle.dataBaseName = dataBaseName ;NSString * dataBaseFile = [dataBaseHandle dataBaseFile];// 打开数据库int result = sqlite3_open([dataBaseFile UTF8String], &db);if (result == SQLITE_OK) {// 创建数据库表语句 , primary key autoincrement 修饰主键在表中值是唯一存在(最后一个单词自动增加)// 条件:// 1.表中必须要有一个主键;// 2.在插入数据时主键自动增加使用 autoincrement 修饰;// 3.主键的值在表中是唯一的,如果插入的数据主键值一样则不能添加在表内NSString * sqliteStr = @"create table if not exists StudentList(stu_number integer primary key autoincrement,stu_name text,stu_gender text,stu_age integer)";// 执行语句sqlite3_exec(db, [sqliteStr UTF8String], NULL, NULL, NULL);}return dataBaseHandle ;
}// 数据库文件存放所在的 Caches 文件夹路径
-(NSString *)dataBasePath
{return [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
}// 数据库文件路径
-(NSString *)dataBaseFile
{return [[self dataBasePath] stringByAppendingPathComponent:[self.dataBaseName stringByAppendingString:@".db"]];
}// 打开数据库
-(void)openDataBase
{NSString * dataBaseFile = [self dataBaseFile];NSLog(@"%@",dataBaseFile);int result = sqlite3_open([dataBaseFile UTF8String], &db);if (result == SQLITE_OK) {NSLog(@"打开成功");}else{NSLog(@"打开失败");}
}// 关闭数据库
-(void)closeDataBase
{int result = sqlite3_close(db);NSLog(@"%@",result == SQLITE_OK ? @"关闭成功":@"关闭失败");
}// 插入数据
-(void)insertDataWithKeyValues:(StudentEntity *)entity
{// 1.打开数据库[self openDataBase];// 2.插入语句NSString * sqlStr = @"insert into StudentList(stu_name,stu_gender,stu_age,stu_number)values(?,?,?,?)";// 3.创建数据管理指针sqlite3_stmt * stmt = nil ;// 4.验证数据库语句,int result = sqlite3_prepare_v2(db, [sqlStr UTF8String], -1, &stmt, NULL);if (result == SQLITE_OK) {NSLog(@"可以插入数据");// 5.帮定数据// 参数:数据库管理指针 , 在 sqlStr 的第n个 ?, 数据库语句 , 语句长度(-1表示自动计算长度) ,sqlite3_bind_text(stmt, 1, [entity.name UTF8String], -1, NULL);sqlite3_bind_text(stmt, 2, [entity.gender UTF8String], -1, NULL);sqlite3_bind_int(stmt, 3, (int)entity.age);sqlite3_bind_int(stmt, 4, (int)entity.number);// 6.让 sql 语句执行sqlite3_step(stmt);}// 7.释放sqlite3_finalize(stmt);// 8.关闭数据库[self closeDataBase];
}// 更新数据
-(void)updateStudentGender:(NSString *)gender byNumber:(NSInteger)number
{[self openDataBase];sqlite3_stmt * stmt = nil ;NSString * sql = @"update StudentList set stu_gender = ? where stu_number = ?";int result = sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL);if (result == SQLITE_OK) { // 是否可以执行sqlite3_bind_text(stmt, 1, [gender UTF8String], -1, NULL);sqlite3_bind_int(stmt, 2, (int)number);sqlite3_step(stmt);}sqlite3_finalize(stmt);[self closeDataBase];
}// 查询所有数据
-(NSArray<StudentEntity *> *)selectAllKeyValues
{// 1.打开数据库[self openDataBase];// 2.准备语句NSString * sql = @"select * from StudentList ";// 3.创建数据管理指针sqlite3_stmt * stmt = nil ;// 4.验证语句是否正确int result = sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL);NSMutableArray * mArr = [[NSMutableArray alloc] initWithCapacity:0];if (result == SQLITE_OK) {// 5.获取数据while (sqlite3_step(stmt) == SQLITE_ROW) {StudentEntity * entity = [[StudentEntity alloc] init];[mArr addObject:entity];entity.number = sqlite3_column_int(stmt, 0);entity.name = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, 1)];entity.gender = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, 2)];entity.age = sqlite3_column_int(stmt, 3);}}// 6.释放 和 关闭数据库sqlite3_finalize(stmt);[self closeDataBase];return mArr ;
}// 查询某一个满足条件的数据
-(StudentEntity *)selectOneStudentByNumber:(NSInteger)number
{[self openDataBase];// 数据库语句:* 表示每条数据的所有字段;? 表示需要帮定的值NSString * sql = @"select * from StudentList where stu_number = ?";// 多条件查询如:@"select * from StudentList where stu_number = ? and stu_name = ?"// @"select * from StudentList where stu_number = ? or stu_name"// @"select * from StudentList where stu_number > ?"// @"select * from StudentList where stu_number > ? limit 5" 满足条件的5条数据// @"select * from StudentList where stu_number > ? limit 3,5" 跳过前三条数据 接着取后5条// @"select * from StudentList where stu_number > ? order by stu_age disc " 在数据库中的数据满足条件 stu_number > ?(帮定的值) 选出的个数,然后以 stu_age 列把数据降序排列// @"select stu_name,stu_age from StudentList where ...... " 选出满足条件数据条的 stu_name 和 stu_age 值// 创建数据管理指针sqlite3_stmt * stmt = nil ;StudentEntity * entity = [[StudentEntity alloc] init];// 验证语句是否正确int result = sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL);if (result == SQLITE_OK) {// 帮定参数sqlite3_bind_int(stmt, 1, (int)number);sqlite3_bind_text(stmt, 2, [@"李四" UTF8String], -1, NULL);while (sqlite3_step(stmt) == SQLITE_ROW) {entity.number = sqlite3_column_int(stmt, 0);entity.name = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, 1)];entity.gender = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, 2)];entity.age = sqlite3_column_int(stmt, 3);}}sqlite3_finalize(stmt);[self closeDataBase];return entity ;
}// 模糊查询
-(StudentEntity *)selectOneStudentLikeName:(NSString *)likeName
{[self openDataBase];sqlite3_stmt * stmt = nil ;StudentEntity * entit = [[StudentEntity alloc] init] ;NSString * sql = [NSString stringWithFormat:@"select * from StudentList where stu_name like '%%%@%%'",likeName];int result = sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL);if (result == SQLITE_OK) {NSLog(@"可以模糊查询");// sqlite3_bind_text(stmt, 1, [likeName UTF8String], -1, NULL);while (sqlite3_step(stmt) == SQLITE_ROW) {entit.number = sqlite3_column_int(stmt, 0);entit.name = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, 1)];entit.gender = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, 2)];entit.age = sqlite3_column_int(stmt, 3);}}sqlite3_finalize(stmt);[self closeDataBase];return entit ;
}// 删除表中的数据
-(void)deleteOneStudentByNumber:(NSInteger)number
{[self openDataBase];NSString * sql = @"delete from StudentList where stu_number = ?";sqlite3_stmt * stmt = nil ;int result = sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL);if (result == SQLITE_OK) {sqlite3_bind_int(stmt, 1, (int)number);// 执行语句sqlite3_step(stmt);}sqlite3_finalize(stmt);[self closeDataBase];
}// 删除整个表
-(void)dropTable
{[self openDataBase];NSString * sql = @"drop table StudentList";sqlite3_stmt * stmt = nil ;int result = sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL);if (result == SQLITE_OK) {NSLog(@"成功删除当前表");sqlite3_step(stmt);}sqlite3_finalize(stmt);[self closeDataBase];
}@end
3.3 使用数据库操作的测试代码
//
// ViewController.h
// DataBaseDome
//
// Created by 瞿杰 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//#import <UIKit/UIKit.h>@interface ViewController : UIViewController@end
//
// ViewController.m
// DataBaseDome
//
// Created by 瞿杰 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//#import "ViewController.h"#import "DataBaseHandle.h"
#import "StudentEntity.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];DataBaseHandle * dataBaseHandle = [DataBaseHandle dataBaseHandleWithDataBaseName:@"StudentDB"];// 查询所有缓存的数据NSArray * allStudents = [dataBaseHandle selectAllKeyValues];// 1.插入数据StudentEntity * entity = [[StudentEntity alloc] init];entity.number = 1000 ;entity.name = @"张三";entity.gender = @"男";entity.age = 20 ;StudentEntity * entity2 = [[StudentEntity alloc] init];entity2.number = 1001 ;entity2.name = @"李四";entity2.gender = @"女";entity2.age = 25 ;[dataBaseHandle insertDataWithKeyValues:entity];[dataBaseHandle insertDataWithKeyValues:entity2];// 2.查询所有数据allStudents = [dataBaseHandle selectAllKeyValues];// 查询单个数据StudentEntity * selectStudent = [dataBaseHandle selectOneStudentByNumber:1000];StudentEntity * selectStudent2 = [dataBaseHandle selectOneStudentByNumber:1001];// 3.更新数据[dataBaseHandle updateStudentGender:@"女" byNumber:1000];[dataBaseHandle updateStudentGender:@"男" byNumber:1001];// 查询所有数据allStudents = [dataBaseHandle selectAllKeyValues];[dataBaseHandle deleteOneStudentByNumber:1001];// 查询所有数据allStudents = [dataBaseHandle selectAllKeyValues];// 查询单个数据selectStudent = [dataBaseHandle selectOneStudentByNumber:1000];selectStudent2 = [dataBaseHandle selectOneStudentByNumber:1001];// 删除整张表[dataBaseHandle dropTable];// 查询所有数据allStudents = [dataBaseHandle selectAllKeyValues];
}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}@end
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