一、sqlite3 使用操作
前提:在項目中導入 libsqlite3.0.tdb 數據庫。
1.sqlite3 相關一些基本函數用法:
1.1、打開數據庫
SQLITE_API int sqlite3_open(
constchar *filename, /* Database filename (UTF-8) */
sqlite3 **ppDb /* OUT: SQLite db handle */
);
該函數傳的兩個參數如下使用,例:
static sqlite3 * db ;
NSString * dataBaseFile = [dataBaseHandledataBaseFile];
int result = sqlite3_open([dataBaseFileUTF8String], &db);
if (result == SQLITE_OK) //說明已經打開數據庫;
1.2、當數據庫被打開後執行創建數據庫表:
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 */
);
// 創建數據庫表語句 , primary key autoincrement修飾主鍵在表中值是唯一存在(最後一個單詞自動增加)
// 條件:
// 1.表中必須要有一個主鍵;
// 2.在插入數據時主鍵自動增加使用 autoincrement修飾;
// 3.主鍵的值在表中是唯一的,如果插入的數據主鍵值一樣則不能添加在表內
NSString * sqliteStr = @"create table if not exists StudentList(stu_number integer primary key autoincrement,stu_name text,stu_gender text,stu_age integer)";
// 執行語句
sqlite3_exec(db, [sqliteStrUTF8String], NULL,NULL, NULL);
1.3、關閉數據庫
int result = sqlite3_close(db);
NSLog(@"%@",result ==SQLITE_OK ? @"關閉成功":@"關閉失敗");
1.4、插入數據相關幾個函數
1.4.1、驗證數據庫語句,nByte 傳 -1 時自動計算 zSql 數據庫語句長度
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、數據庫管理指針 sqlite3_stmt 類型
typedef structsqlite3_stmt sqlite3_stmt;
1.4.3、綁定數據
// 第二個參數表示 數據庫語句中的第 k 個 "?" ,從 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 語句:
@"select * from StudentList where stu_number = ? and stu_name = ?"
// 綁定參數據如下:
// 幫定參數,在之前先省去了一些步驟,稍後看例子。
sqlite3_bind_int(stmt, 1, (int)number);
sqlite3_bind_text(stmt, 2, [@"李四"UTF8String], -1,NULL);
1.4.4、執行數據庫語句
SQLITE_API int sqlite3_step(sqlite3_stmt*);
1.4.5、釋放數據庫管理指針
SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
插入數據示例:
// 插入數據
-(void)insertDataWithKeyValues:(StudentEntity *)entity
{
// 1.打開數據庫
[self openDataBase];
// 2.插入語句
NSString * sqlStr = @"insert into StudentList(stu_name,stu_gender,stu_age,stu_number)values(?,?,?,?)";
// 3.創建數據管理指針
sqlite3_stmt * stmt = nil ;
// 4.驗證數據庫語句,
int result = sqlite3_prepare_v2(db, [sqlStr UTF8String], -1, &stmt, NULL);
if (result == SQLITE_OK) {
NSLog(@"可以插入數據");
// 5.幫定數據
// 參數:數據庫管理指針 , 在 sqlStr 的第n個 ?, 數據庫語句 , 語句長度(-1表示自動計算長度) ,
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.讓 sql 語句執行
sqlite3_step(stmt);
}
// 7.釋放
sqlite3_finalize(stmt);
// 8.關閉數據庫
[self closeDataBase];
}
1.5、從數據庫中取出每條數據的每一列對應的數據
// iCol 表示每個字段所在的列位置,從 0 開始。
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、數據庫操作語句
ListName 爲創建的表名,one 、two 和 three 都是表中每一列的字段。
// 創建數據庫表
@"create table if not exists ListName(one text primary key autoincrement , two text , three integer,......)";
// 插入數據
@"insert into ListName(one , two , three,....) values(? , ? , ? , ....) ";
// 查詢
@"select * from ListName" // 查詢表中所有數據
@"select * from ListName where one = ? " //帶有一個條件的查詢
@"select * from ListName where one = ? and two = ?" // 滿足一個條件的查詢
@"select * from ListName where one = ? or three = ?" // 滿足其中任意一個條件的查詢
@"select * from ListName where three > ?" // 表中滿足 three > 當前綁定的值 的 數據
@"select one,three from ListName where two = ? order by three disc(或是 asce)" // 查詢表中滿足(two = 當前綁定的值)條件的 one 和 three 值,並以 three 大小降序排列返回
@"select * from ListName where three > ? limit 5" // 滿足條件的5條數據
@"select * from ListName where three > ? limit 3,5" // 跳過前三條數據 接着取後5條
@"select one,two from ListName where ...... " //選出滿足條件數據條的 one 和 two 值
// 模糊查詢所有字段 two 包含 likeName 內容的數據都找出來
[NSString stringWithFormat:@"select * from ListName where two like '%%%@%%'",likeName];
// 修改數據
@"update ListName set one = ? where three >= ?"
// 刪除數據
@"delete from ListName" // 刪除表中所有數據
@"delete from ListName where one = ?" // 刪除表中滿足條件的數據
// 刪除整張表
@"drop table ListName"
2. 把 c 的字符串轉換成 OC 中的 NSString 類型
[NSStringstringWithUTF8String:(char *)sqlite3_column_text(stmt,1)]
3.整個項目代碼
3.1數據模型文件代碼
//
// StudentEntity.h
// DataBaseDome
//
// Created by 瞿傑 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 瞿傑 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//
#import "StudentEntity.h"
@implementation StudentEntity
@end
3.2 數據庫操作文件
//
// DataBaseHandle.h
// DataBaseDome
//
// Created by 瞿傑 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//
#import <Foundation/Foundation.h>
@class StudentEntity ;
@interface DataBaseHandle : NSObject
+(instancetype)dataBaseHandleWithDataBaseName:(NSString *)dataBaseName;
// 打開數據庫
-(void)openDataBase ;
// 關閉數據庫
-(void)closeDataBase ;
// 插入數據
-(void)insertDataWithKeyValues:(StudentEntity *)entity ;
// 更新
-(void)updateStudentGender:(NSString *)gender byNumber:(NSInteger)number ;
// 查詢
// 查詢所有數據
-(NSArray<StudentEntity *> *)selectAllKeyValues ;
// 根據條件查詢
-(StudentEntity *)selectOneStudentByNumber:(NSInteger)number ;
// 模糊查詢,只要包含 likeName 內容
-(StudentEntity *)selectOneStudentLikeName:(NSString *)likeName ;
// 刪除表中數據
-(void)deleteOneStudentByNumber:(NSInteger)number ;
// 刪除表
-(void)dropTable;
@end
//
// DataBaseHandle.m
// DataBaseDome
//
// Created by 瞿傑 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 DataBaseHandle
static sqlite3 * db ;
+(instancetype)dataBaseHandleWithDataBaseName:(NSString *)dataBaseName
{
DataBaseHandle * dataBaseHandle = [[self alloc] init];
dataBaseHandle.dataBaseName = dataBaseName ;
NSString * dataBaseFile = [dataBaseHandle dataBaseFile];
// 打開數據庫
int result = sqlite3_open([dataBaseFile UTF8String], &db);
if (result == SQLITE_OK) {
// 創建數據庫表語句 , primary key autoincrement 修飾主鍵在表中值是唯一存在(最後一個單詞自動增加)
// 條件:
// 1.表中必須要有一個主鍵;
// 2.在插入數據時主鍵自動增加使用 autoincrement 修飾;
// 3.主鍵的值在表中是唯一的,如果插入的數據主鍵值一樣則不能添加在表內
NSString * sqliteStr = @"create table if not exists StudentList(stu_number integer primary key autoincrement,stu_name text,stu_gender text,stu_age integer)";
// 執行語句
sqlite3_exec(db, [sqliteStr UTF8String], NULL, NULL, NULL);
}
return dataBaseHandle ;
}
// 數據庫文件存放所在的 Caches 文件夾路徑
-(NSString *)dataBasePath
{
return [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
}
// 數據庫文件路徑
-(NSString *)dataBaseFile
{
return [[self dataBasePath] stringByAppendingPathComponent:[self.dataBaseName stringByAppendingString:@".db"]];
}
// 打開數據庫
-(void)openDataBase
{
NSString * dataBaseFile = [self dataBaseFile];
NSLog(@"%@",dataBaseFile);
int result = sqlite3_open([dataBaseFile UTF8String], &db);
if (result == SQLITE_OK) {
NSLog(@"打開成功");
}
else{
NSLog(@"打開失敗");
}
}
// 關閉數據庫
-(void)closeDataBase
{
int result = sqlite3_close(db);
NSLog(@"%@",result == SQLITE_OK ? @"關閉成功":@"關閉失敗");
}
// 插入數據
-(void)insertDataWithKeyValues:(StudentEntity *)entity
{
// 1.打開數據庫
[self openDataBase];
// 2.插入語句
NSString * sqlStr = @"insert into StudentList(stu_name,stu_gender,stu_age,stu_number)values(?,?,?,?)";
// 3.創建數據管理指針
sqlite3_stmt * stmt = nil ;
// 4.驗證數據庫語句,
int result = sqlite3_prepare_v2(db, [sqlStr UTF8String], -1, &stmt, NULL);
if (result == SQLITE_OK) {
NSLog(@"可以插入數據");
// 5.幫定數據
// 參數:數據庫管理指針 , 在 sqlStr 的第n個 ?, 數據庫語句 , 語句長度(-1表示自動計算長度) ,
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.讓 sql 語句執行
sqlite3_step(stmt);
}
// 7.釋放
sqlite3_finalize(stmt);
// 8.關閉數據庫
[self closeDataBase];
}
// 更新數據
-(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) { // 是否可以執行
sqlite3_bind_text(stmt, 1, [gender UTF8String], -1, NULL);
sqlite3_bind_int(stmt, 2, (int)number);
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[self closeDataBase];
}
// 查詢所有數據
-(NSArray<StudentEntity *> *)selectAllKeyValues
{
// 1.打開數據庫
[self openDataBase];
// 2.準備語句
NSString * sql = @"select * from StudentList ";
// 3.創建數據管理指針
sqlite3_stmt * stmt = nil ;
// 4.驗證語句是否正確
int result = sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL);
NSMutableArray * mArr = [[NSMutableArray alloc] initWithCapacity:0];
if (result == SQLITE_OK) {
// 5.獲取數據
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.釋放 和 關閉數據庫
sqlite3_finalize(stmt);
[self closeDataBase];
return mArr ;
}
// 查詢某一個滿足條件的數據
-(StudentEntity *)selectOneStudentByNumber:(NSInteger)number
{
[self openDataBase];
// 數據庫語句:* 表示每條數據的所有字段;? 表示需要幫定的值
NSString * sql = @"select * from StudentList where stu_number = ?";
// 多條件查詢如:@"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" 滿足條件的5條數據
// @"select * from StudentList where stu_number > ? limit 3,5" 跳過前三條數據 接着取後5條
// @"select * from StudentList where stu_number > ? order by stu_age disc " 在數據庫中的數據滿足條件 stu_number > ?(幫定的值) 選出的個數,然後以 stu_age 列把數據降序排列
// @"select stu_name,stu_age from StudentList where ...... " 選出滿足條件數據條的 stu_name 和 stu_age 值
// 創建數據管理指針
sqlite3_stmt * stmt = nil ;
StudentEntity * entity = [[StudentEntity alloc] init];
// 驗證語句是否正確
int result = sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL);
if (result == SQLITE_OK) {
// 幫定參數
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 ;
}
// 模糊查詢
-(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(@"可以模糊查詢");
// 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 ;
}
// 刪除表中的數據
-(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);
// 執行語句
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[self closeDataBase];
}
// 刪除整個表
-(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(@"成功刪除當前表");
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[self closeDataBase];
}
@end
3.3 使用數據庫操作的測試代碼
//
// ViewController.h
// DataBaseDome
//
// Created by 瞿傑 on 2017/6/19.
// Copyright © 2017年 yiniu. All rights reserved.
//
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController
@end
//
// ViewController.m
// DataBaseDome
//
// Created by 瞿傑 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"];
// 查詢所有緩存的數據
NSArray * allStudents = [dataBaseHandle selectAllKeyValues];
// 1.插入數據
StudentEntity * entity = [[StudentEntity alloc] init];
entity.number = 1000 ;
entity.name = @"張三";
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.查詢所有數據
allStudents = [dataBaseHandle selectAllKeyValues];
// 查詢單個數據
StudentEntity * selectStudent = [dataBaseHandle selectOneStudentByNumber:1000];
StudentEntity * selectStudent2 = [dataBaseHandle selectOneStudentByNumber:1001];
// 3.更新數據
[dataBaseHandle updateStudentGender:@"女" byNumber:1000];
[dataBaseHandle updateStudentGender:@"男" byNumber:1001];
// 查詢所有數據
allStudents = [dataBaseHandle selectAllKeyValues];
[dataBaseHandle deleteOneStudentByNumber:1001];
// 查詢所有數據
allStudents = [dataBaseHandle selectAllKeyValues];
// 查詢單個數據
selectStudent = [dataBaseHandle selectOneStudentByNumber:1000];
selectStudent2 = [dataBaseHandle selectOneStudentByNumber:1001];
// 刪除整張表
[dataBaseHandle dropTable];
// 查詢所有數據
allStudents = [dataBaseHandle selectAllKeyValues];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end