数据库封装
#import <Foundation/Foundation.h>
#import "Student.h"
#import <sqlite3.h>
@interface SqliteManager : NSObject
{
sqlite3 *db;
}
-(void) open;
-(void) insertStudent:(Student *) s;
-(void) updateStudent:(Student *) s;
-(void) deleteStudent:(Student *) s;
-(NSArray *) searchStudent:(Student *) s;
-(void) close;
@end
#import "SqliteManager.h"
@implementation SqliteManager
-(void) open;
{
NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/student.sqlite"];
//打开数据库文件 第一个参数代表数据库文件的路径，注意需要调用UTF8String方法将NSString转换成c的字符串格式，第二个参数代表数据库对象。该方法如果返回0，代表数据库打开成功，如果该路径没有数据库文件，则先创建再打开，否则直接打开
int a = sqlite3_open([path UTF8String], &db);
if (a == 0) {
[self createTable];
}
}
//创建数据库表
-(void) createTable
{
NSString *s = @"create table if not exists Student(name TEXT)";
[self execSql:s ];
}
-(void)execSql :(NSString *) str
{
sqlite3_exec(db, [str UTF8String], NULL, NULL, NULL);
}
-(void) insertStudent:(Student *) s
{
//数据库增加数据
//sql插入语句：insert into Student(表名) (要进行保存的字段名，名字之间用逗号隔开) values(要保存的实际数据，多个数据用逗号隔开，注意：此处数据要与前面的字段名保持一致，且如果是TEXT类型，需要用单引号引起来)
NSString *sql = [NSStringstringWithFormat:@"insert into Student (name) values('%@')",s.name];
[self execSql:sql];
}
//搜索
-(NSArray *) searchStudent:(Student *) s
{
NSMutableArray *arr = [NSMutableArrayarray];
NSString *sql = nil;
if ([SqliteManager isBlankString:s]) {
sql = @"select * from Student";
}else{
sql = [NSStringstringWithFormat: @"select * from Student where name = '%@'",s];
}
sqlite3_stmt *_stmt = nil;
int res = sqlite3_prepare(db, [sql UTF8String], -1, &_stmt, NULL);
if (res == 0) {
while (SQLITE_ROW == sqlite3_step(_stmt)) {
const unsigned char *name = sqlite3_column_text(_stmt, 0);
Student *s = [[Student alloc] init];
s.name = [NSString stringWithUTF8String:(const char *)name];
[arr addObject:s];
}
}
return arr;
}
+ (BOOL)isBlankString:(NSString *)string{
if (string == nil) {
return YES;
}
if (string == NULL) {
return YES;
}
if ([string isKindOfClass:[NSNull class]]) {
return YES;
}
if (string.length == 0) {
return YES;
}
returnNO;
}
-(void) close
{
sqlite3_close(db);
}
@end
