PL / SQL从两个表中选择

Question

以这两个表为例：

CREATE OR REPLACE VIEW EXAMPLE
AS
SELECT ENAME, DNAME FROM EMP, DEPT
WHERE DNAME IN ('ACCOUNTING','SALES);

我想选择在“会计”和“销售”部门工作的员工的姓名，所以我会这样做：

    var stateChangingButton = L.easyButton({
            states: [{
                    stateName: 'ButtonOff',      
                    icon:      'X',               
                    title:     'Turn Button On', 
                    onClick: function(btn, map) {    
                            btn.button.style.backgroundColor = 'red';
                            btn.state('ButtonOn');
                            map.on('mousedown', getClickLocation);
                            map.on('mouseup', getReleaseLocation);
                            map.on('mouseup', toGeoJsonBounds);
                            map.on('mouseup', addSelectionLayer);
                            map.on('mouseup', addColorSelection);                                
                    }
                }, {
                    stateName: 'ButtonOn',
                    icon:      'X',
                    title:     'Turn Button Off',
                    onClick: function(btn, map) {
                        btn.state('ButtonOff');
                            btn.state('ButtonOff');
                            btn.button.style.backgroundColor = 'white';
                            map.off('mousedown', getClickLocation);
                            map.off('mouseup', getReleaseLocation);
                            map.off('mouseup', toGeoJsonBounds);
                            map.off('mouseup', addSelectionLayer);
                            map.off('mouseup', addColorSelection);                             

                    }
                    }]
                });

                stateChangingButton.addTo(map);

但我完全不确定这是否正确。我应该使用dname加入ename

在哪里ename.dname IN（'ACCOUNTING'，'SALES'）可能？

提前谢谢

Answer 1

您应该通过DEPTNO列加入EMP表和DEPT表。 之后使用条件WHERE DNAME IN（'ACCOUNTING'，'SALES'） 查询如下所示：

SELECT e.ENAME, d.DNAME 
FROM EMP e
left join DEPT d on d.DEPTNO = e.DEPTNO
WHERE d.DNAME IN ('ACCOUNTING','SALES');