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文章出处:http://blog.csdn.net/iukey | sqlite 是个好东西,对于移动平台来说。一直想写有关sqlite的教程,但是不知道从何写起,考虑了很久,还是从一个小Demo 谈起吧。我写了一个精简版的词典,实现了增删查改的基本功能。
工程结构如下
。最后效果图如下
。
效果图中可以看到,我查询 "cc",所有相关条目都查询出来了。
好了,现在开始讲解我的项目。首先可以看我的工程目录,QueryResultList 是界面控制类,DB 是数据库操作类。
整个项目的流程:我们在search框中输入要查询的内容点击搜索,底层模糊查询返回结果显示在tableView中。
我们先从底层的操作讲起,目前我就实现了插入与查询操作,删除与修改以后再补上:
1.创建数据库
- (const char*)getFilePath{//获取数据库路径return [[NSString stringWithFormat:@"%@/Documents/l",NSHomeDirectory() ] UTF8String];}// DB.h//iukey#import <Foundation/Foundation.h>#import "/usr/include/sqlite3.h"@interface DB : NSObject{sqlite3* pdb;//数据库句柄}@property(nonatomic,assign)sqlite3* pdb;- (BOOL)insertRecordWithEN:(NSString*)en CN:(NSString*)cn Comment:(NSString*)comment;//插入一条纪录- (NSMutableArray*)quary:(NSString*)str;//查询- (const char*)getFilePath;//获取数据库路径- (BOOL)createDB;//创建数据库- (BOOL)createTable;//创建表@end2.创建表- (BOOL)createTable{char* err;char* sql = "create table dictionary(ID integer primary key autoincrement,en nvarchar(64),cn nvarchar(128),comment nvarchar(256))";//创建表语句if (sql==NULL) {return NO;}if (SQLITE_OK != sqlite3_open([self getFilePath ], &pdb)){return NO;}if (SQLITE_OK == sqlite3_exec(pdb, sql, NULL, NULL, &err)) {//执行创建表语句成功sqlite3_close(pdb);return YES;}else{//创建表失败return NO;}}3.插入一条纪录- (BOOL)insertRecordWithEN:(NSString*)en CN:(NSString*)cn Comment:(NSString*)comment{int ret = 0;if (SQLITE_OK != sqlite3_open([self getFilePath ], &pdb)){//打开数据库return NO;}char* sql = "insert into dictionary(en,cn,comment) values(?,?,?);";//插入语句,3个参数sqlite3_stmt* stmt;//if (sqlite3_prepare_v2(pdb, sql, -1, &stmt, nil)==SQLITE_OK) {//准备语句sqlite3_bind_text(stmt, 1, [en UTF8String], -1, NULL);//绑定参数sqlite3_bind_text(stmt, 2, [cn UTF8String], -1, NULL);sqlite3_bind_text(stmt, 3, [comment UTF8String], -1, NULL);}else{return NO;}if (SQLITE_DONE == (ret = sqlite3_step(stmt))) {//执行查询sqlite3_finalize(stmt);sqlite3_close(pdb);return YES;}else{return NO;}}4.查询- (NSMutableArray*)quary:(NSString *)str{NSMutableArray* arr =[[NSMutableArray alloc]init];//存放查询结果if (SQLITE_OK != sqlite3_open([self getFilePath ], &pdb)){return NO;}char* sql = "select * from dictionary where en like ? or cn like ? or comment like ?;";//查询语句sqlite3_stmt* stmt;if (sqlite3_prepare_v2(pdb, sql, -1, &stmt, nil)==SQLITE_OK) {//准备sqlite3_bind_text(stmt, 1,[[NSString stringWithFormat:@"%%%@%%",str]UTF8String], -1, NULL);sqlite3_bind_text(stmt, 2, [[NSString stringWithFormat:@"%%%@%%",str]UTF8String], -1, NULL);sqlite3_bind_text(stmt, 3, [[NSString stringWithFormat:@"%%%@%%",str]UTF8String], -1, NULL);}else{return nil;}while( SQLITE_ROW == sqlite3_step(stmt) ){//执行char* _en = (char*)sqlite3_column_text(stmt, 1);char* _cn = (char*)sqlite3_column_text(stmt, 2);char* _comment = (char*)sqlite3_column_text(stmt, 3);NSMutableDictionary* dict = [[NSMutableDictionary alloc]init];//单条纪录[dict setObject:[NSString stringWithCString:_en encoding:NSUTF8StringEncoding] forKey:@"kEN"];[dict setObject:[NSString stringWithCString:_cn encoding:NSUTF8StringEncoding] forKey:@"kCN"];[dict setObject:[NSString stringWithCString:_comment encoding:NSUTF8StringEncoding] forKey:@"kCOMMENT"];[arr addObject:dict];//插入到结果数组}sqlite3_finalize(stmt);sqlite3_close(pdb);return [arr autorelease];//返回查询结果数组}5.DB 初始化 我先定义了一个宏,用来标识是否是第一次运行程序,如果是第一次运行就要运行创建数据库与表的函数,否则就不运行,具体看代码:
#define FIRSTINIT 1//第一次运行则设为1,否则就是0- (id)init{self = [super init];if (self!=nil) {#if FIRSTINIT[self createDB];[self createTable];[self insertRecordWithEN:@"cctv1" CN:@"央视1套" Comment:@"SB电视台1"];//为了方便测试我插入了一些纪录[self insertRecordWithEN:@"cctv2" CN:@"央视2套" Comment:@"SB电视台2"];[self insertRecordWithEN:@"cctv3" CN:@"央视3套" Comment:@"SB电视台3"];[self insertRecordWithEN:@"cctv4" CN:@"央视4套" Comment:@"SB电视台4"];[self insertRecordWithEN:@"cctv5" CN:@"央视5套" Comment:@"SB电视台5"];[self insertRecordWithEN:@"cctv6" CN:@"央视6套" Comment:@"SB电视台6"];[self insertRecordWithEN:@"cctv7" CN:@"央视7套" Comment:@"SB电视台7"];[self insertRecordWithEN:@"cctv8" CN:@"央视8套" Comment:@"SB电视台8"];[self insertRecordWithEN:@"cctv9" CN:@"央视9套" Comment:@"SB电视台9"];[self insertRecordWithEN:@"cctv10" CN:@"央视10套" Comment:@"SB电视台10"];[self insertRecordWithEN:@"cctv11" CN:@"央视11套" Comment:@"SB电视台11"];[self insertRecordWithEN:@"cctv12" CN:@"央视12套" Comment:@"SB电视台12"];#endif}return self;}底层的数据库暂时就这些,接着讲上层的界面部分// QueryResultList.h// iukey#import <UIKit/UIKit.h>#import "DB.h"@interface QueryResultList : UITableViewController<UISearchBarDelegate>{NSMutableArray* mArr;//tableView数据源DB* db ;//数据库对象UISearchBar* searchBar ;//搜索框}@property(nonatomic,retain)NSMutableArray* mArr;@property(nonatomic,retain)DB* db;@property(nonatomic,retain)UISearchBar* searchBar ;@end- (id)initWithStyle:(UITableViewStyle)style{self = [super initWithStyle:style];if (self) {mArr = [[NSMutableArray alloc]init];//表数据源db =[[DB alloc]init];//数据库控制器searchBar = [[UISearchBar alloc]initWithFrame:CGRectMake(44.0,0,200.0,44)];//搜索控件searchBar.delegate=self;//设置搜索控件的委托self.navigationItem.titleView = searchBar;}return self;}接下来我们实现表格数据源委托#pragma mark - Table view data source- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{return 1;//分区数}- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{return [mArr count];//行数}- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{static NSString *CellIdentifier = @"Cell";UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];for ( UIView* view in cell.contentView.subviews) {[view removeFromSuperview];}if (cell == nil) {cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];}UILabel* lblEN = [[UILabel alloc]initWithFrame:CGRectMake(5.0, 5.0, 300.0, 30.0)];//显示英文的文字标签控件UILabel* lblCN = [[UILabel alloc]initWithFrame:CGRectMake(5.0, 35.0, 300.0, 30.0)];//中文UILabel* lblComment = [[UILabel alloc]initWithFrame:CGRectMake(5.0, 65.0, 300.0, 30.0)];//详细//背景颜色清掉lblEN.backgroundColor = [UIColor clearColor];lblCN.backgroundColor = [UIColor clearColor];lblComment.backgroundColor = [UIColor clearColor];//lblEN.text = [[mArr objectAtIndex:indexPath.row] objectForKey:@"kEN"];lblCN.text = [[mArr objectAtIndex:indexPath.row] objectForKey:@"kCN"];lblComment.text = [[mArr objectAtIndex:indexPath.row] objectForKey:@"kCOMMENT"];[cell.contentView addSubview:lblEN];[cell.contentView addSubview:lblCN];[cell.contentView addSubview:lblComment];cell.selectionStyle = UITableViewCellSelectionStyleNone;//选中不要高亮[lblEN release];[lblCN release];[lblComment release];return cell;}然后实现搜索委托方法:#pragma mark - UISearchBar delegate- (void) searchBarSearchButtonClicked:(UISearchBar*)activeSearchbar{[mArr removeAllObjects];NSString* query= searchBar.text;NSMutableArray* arr = [db quary:query];for ( NSMutableDictionary* dict in arr) {[mArr addObject:dict];}[searchBar resignFirstResponder];[self.tableView reloadData];}基本就结束了,这只是一个简单的Demo,sqlite的基本使用方法我也会慢慢整理出来,最后附上完整工程文件:DictionaryDemo
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