第四十二篇:IOS 的 sqlite3 一些基本使用

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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




4. 在 git 上的代码仓库DataBaseDome






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