FMDatabase 使用（oc）

1.创建数据库

iOS数据库一般会保存在沙盒文件的Documents中

NSArray *documents=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath=[documents firstObject];
NSString *dbPath=[documentsPath stringByAppendingPathComponent:@"test.db"];
NSLog(@"%@",dbPath);
_dataBase=[FMDatabase databaseWithPath:dbPath];
if ([_dataBase open]) {
	NSLog(@"打开成功");
}else{
	NSLog(@"打开失败");
}
           

2.创建表

NSString *createTableSql=@"create table if not exists Person(id integer primary key autoincrement,name text,age integer)";

BOOL success=[_dataBase executeUpdate:createTableSql];
if (success) {
	NSLog(@"创建表成功");
}else{
	NSLog(@"创建表失败");
}
           

3.增删改查

[self insert];
[self update];
[self delete];
[self select];
//关闭数据库
[_dataBase close];
           

增删改查

-(void)insert//插入数据
{
	NSString *insertSQL=@"insert into Person (name,age) values (?,?)";
	BOOL success=[_dataBase executeUpdate:insertSQL,@"王五",@19];
	if (success) {
		NSLog(@"插入成功");
	}else{
		NSLog(@"插入失败");
	}
}
-(void)update//改数据
{
	NSString *updateSQL=@"update Person set name=?,age=? where id=?";
	BOOL success=[_dataBase executeUpdate:updateSQL,@"王五",@20,@1];
	if (success) {
		NSLog(@"更新成功");
	}else{
		NSLog(@"更新失败");
	}
}
-(void)delete//删除数据
{
	NSString *deleteSQL=@"delete from Person where age=? ";
	BOOL success=[_dataBase executeUpdate:deleteSQL,@20];
	if (success) {
		NSLog(@"删除成功");
	}else{
		NSLog(@"删除失败");
	}
}
-(void)select//查询数据
{
	NSString *selectSQL=@"select * from Person where id =?";
	//查询返回的为一个结果集

	FMResultSet *set=[_dataBase executeQuery:selectSQL,@5];

	//需要对结果集进行遍历操作

	[set next];//获取吓一跳记录,如果没有下一条,返回NO;
	//取数据
	NSString *name=[set stringForColumn:@"name"];
	NSInteger ID=[set intForColumn:@"id"];
	NSLog(@"%@,ID=%ld",name,ID);
}