在iOS中实现SQLite数据库的操作:1.导入框架(libsqlite3.0.tbd) 2.导入头文件<sqlite3.h> 3.实现数据的增删改查
实现简单 SQLite数据库操作 的 demo 具体过程:
1.创建名为 SQLite_Manage 的.h .m 文件,导入头文件 <sqlite3.h>
2.数据库在一个app中只有一个,使用单例模式:(代码如下)
+ (SQLite_Manager *)sharedManager{
static SQLite_Manager *manager = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
manager = [[SQLite_Manager alloc]init];
});
return manager;
}
3.打开数据库,代码如下:
- (void)open{
//document路径
NSString *docment = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
//sqlite 路径
NSString *sqlitePath = [docment stringByAppendingPathComponent:@"database.sqlite"];
//打开数据库
int result = sqlite3_open(sqlitePath.UTF8String, &db);
//判断数据库是否打开成功
if (result == SQLITE_OK) {
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"打开成功" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}else {
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"打开失败" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}
}
4.创建表,代码如下:
- (void)creatTable{
//sql语句
NSString *sqlString = @"create table Person (id integer primary key,name text,age integer)";
//执行SQL语句
char *error = nil;
sqlite3_exec(db, sqlString.UTF8String, nil, nil, &error); //判断是否出现了错误
if (error == nil){
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"创建表成功" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}else {
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"创建表失败" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}
}
5.插入数据,代码如下:
- (void)insert{
//sql语句
NSString *sqlString = @"insert into Person ('name','age') values ('Ager',18)";
//执行SQL语句
char *error = nil;
sqlite3_exec(db, sqlString.UTF8String, nil, nil, &error);
//判断是否出现了错误
if (error == nil){
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"插入数据成功" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}else {
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"插入数据失败" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
} }
6.修改数据,代码如下:
- (void)update{
//sql语句
NSString *sqlString = @"update Person set 'name' = 'Arun' where id = 1";
//执行sql语句
char *error = nil;
sqlite3_exec(db, sqlString.UTF8String, nil, nil, &error); //判断是否出现了错误
if (error == nil){
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"数据更新成功" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}else {
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"数据更新失败" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}
}
7.查询数据,代码如下:
- (void)select{
//sql语句
NSString *sqlString = @"select * from Person";
//准备sql
sqlite3_stmt *stmt = nil;
sqlite3_prepare(db, sqlString.UTF8String,-, &stmt, nil);
//单步执行语句
while (sqlite3_step(stmt) == SQLITE_ROW) {
int ID = sqlite3_column_int(stmt, );
const unsigned char *name = sqlite3_column_text(stmt, );
int age = sqlite3_column_int(stmt, );
NSLog(@"%d,%s,%d",ID,name,age);
}
sqlite3_finalize(stmt);
}
8.删除数据,代码如下:
- (void)deleteData{
//sql语句
NSString *sqlString = @"delete from Person where id = 1";
//执行sql语句
char *error = nil;
sqlite3_exec(db, sqlString.UTF8String, nil, nil, &error);
//判断是否出现了错误
if (error == nil){
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"删除成功" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}else {
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"删除失败" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}
}
9.关闭数据库,代码如下:
- (void)close{
//关闭数据库
int result = sqlite3_close(db);
//判断数据库是否关闭成功
if (result == SQLITE_OK) {
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"关闭成功" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}else {
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"数据库执行结果" message:@"关闭失败" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alertView show];
}
}