Question

我从ruby连接到postgres数据库没有问题，但是当他们添加模式时，我感到困惑并且出错了，这是我试图运行的代码：

public class MainActivity extends AppCompatActivity {


private EditText check,check2;
private TextView textView;
private TextInputLayout checkLay,checkLay2;
private Button button;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    initializeWidgets();

    initializeListeners();
}

private void initializeWidgets(){

    check=findViewById(R.id.check);
    check2=findViewById(R.id.check2);
    checkLay2=findViewById(R.id.checkLay2);
    checkLay=findViewById(R.id.checkLay);
    button=findViewById(R.id.button);
    textView=findViewById(R.id.textView);

}

private void initializeListeners() {

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            signUp();
        }
    });
}
private void signUp(){

    boolean isVailed=true;

    int a1,a2;

    String one=check.getText().toString();
    String two=check2.getText().toString();

    if(one.isEmpty()){

        checkLay.setError("YOu need to enter something");
        isVailed=false;
    }
    else {
        if (one.length() > 0)
        {

            a1=Integer.parseInt(one);
            if(a1> 15){
                checkLay.setError("quiz marks must be less than 15");
                isVailed=false;

            }


            else  if(a1 <=15)
            {

                checkLay.setErrorEnabled(false);
                isVailed=true;
            }

        }

    }
    if(two.isEmpty()){

        checkLay2.setError("You need to enter something");
        isVailed=false;
    }
    else{
        if (two.length() > 0)
        {

            a2=Integer.parseInt(two);
            if(a2 > 15)
            { checkLay2.setError("quiz marks must be less than 15");
                isVailed=false;
            }

            else
            if(a2 <=15)
            {
                checkLay2.setErrorEnabled(false);
                isVailed=true;
            }
        }

        if(isVailed)
        {
            int total;
            a1=Integer.parseInt(one);
            a2=Integer.parseInt(two);
            total=a1+a2;
            textView.setText(String.valueOf(total));
        }

    }

我收到了这个错误：

require 'pg'

 @pg_conn = PGconn.connect("xxxxxxx.us-gov-west-1.rds.amazonaws.com", 5432, '', '', "BRCArchive", "yyyy", "zzzz")

count = @pg_conn.exec('SELECT COUNT(*) FROM "brcmanager.Agency"') 
puts count

谢谢，

Answer 1

@pg_conn.exec("set search_path=brcmanager;")

然后

count = @pg_conn.exec('SELECT COUNT(*) FROM Agency')

Answer 2

错误告诉你错了什么。表brcmanager.Agency表不存在于该数据库中，也许您拼错了它？

您可以通过运行此SQL来查看该数据库中存在哪些表：

SELECT * FROM information_schema.tables WHERE table_schema = 'information_schema'

postgres，带有ruby代码模式的数据库

2 个答案: