Question

这是一个简单的查询，可以预期输出。

Private Sub ShowInfo(InfoText As String)
    ' code to query info and show in seperate window
    ' make sure window doesn't get focus
    ' I prefer to use non editable text boxes in my main window
    Me.TextBox1 = InfoText
End Sub

Private Sub Label1_MouseMove(ByVal Button As Integer, ByVal Shift As Integer, ByVal X As Single, ByVal Y As Single)
    ShowInfo "Mouse is over Label1"
End Sub

Private Sub Label2_MouseMove(ByVal Button As Integer, ByVal Shift As Integer, ByVal X As Single, ByVal Y As Single)
    ShowInfo "Mouse is over Label2"
End Sub

Private Sub Label3_MouseMove(ByVal Button As Integer, ByVal Shift As Integer, ByVal X As Single, ByVal Y As Single)
    ShowInfo "Mouse is over Label3"
End Sub

Private Sub UserForm_MouseMove(ByVal Button As Integer, ByVal Shift As Integer, ByVal X As Single, ByVal Y As Single)
    ' this is the exit code
    ' as here we left all labels
    ShowInfo "Mouse is not on a label"
End Sub

这里将相同的查询放在函数中。

select 1.1 as x, 1.1 as y;
x  |  y
-----+-----
1.1 | 1.1
(1 row)

这是输出：

CREATE OR REPLACE FUNCTION foo4(param integer) 
RETURNS TABLE(x float, y float) AS
$$
DECLARE var float;
BEGIN
  var = 1.1;
  RETURN QUERY select var as x, var as y;
END;
$$
LANGUAGE 'plpgsql';

为什么函数以不同方式输出数据？如何将函数输出分为两列？

使用PostgreSQL 10.3和Windows 7/10。

Answer 1

select * from foo4(4);应该会为您提供所需的结果。

Answer 2

试试RETURN QUERY EXECUTE。这将导致查询是动态的而不是静态的。 https://www.postgresql.org/docs/current/static/plpgsql-control-structures.html#AEN63012

返回表格列

2 个答案: