Employee Month-Wise Service Length Using Sql - sql

Question

I am trying to create employee unit-wise service length report from their joining date and have used the following query to do so:
SELECT o.UnitName, p.DeptName, COUNT(m.EmpId) AS cnt,
(SELECT COUNT(m.EmpId) FROM EmpInf m
WHERE m.Desg IN ('Jr. Operator', 'Operator') AND m.Active = 'Active' AND m.DeptId = 2
AND DATEDIFF(MONTH, m.Joindate, GETDATE()) BETWEEN 0 AND 6) AS '0 - 6 Months'
FROM EmpInf m
INNER JOIN Department k ON k.DeptId = m.DeptId
INNER JOIN Section l ON l.secId = m.SecID
INNER JOIN UnitInf o ON o.UnitID = l.UnitName
INNER JOIN Department p ON p.DeptId = m.DeptId
WHERE Desg IN ('Jr. Operator', 'Operator') AND Active = 'Active' AND p.DeptName = 'Production'
GROUP BY o.UnitName, p.DeptName
Expected output as below: (As unit 1 and 4 have entry in the year 2017 means during 0 - 6 months of the year 2017 and there will be many others like 7 - 12, 13 - 24 etc)
Currently getting this:
I guess, having issue with the query and would be glad to know if there are any changes or alternates to do so.
Below is the script:
USE [sample]
GO
/****** Object: Table [dbo].[UnitInf] Script Date: 05/11/2017 21:19:34 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[UnitInf](
[UnitID] [int] IDENTITY(1,1) NOT NULL,
[UnitName] [nvarchar](100) NULL,
CONSTRAINT [PK_UnitInf] PRIMARY KEY CLUSTERED
(
[UnitID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET IDENTITY_INSERT [dbo].[UnitInf] ON
INSERT [dbo].[UnitInf] ([UnitID], [UnitName]) VALUES (1, N'Unit-01')
INSERT [dbo].[UnitInf] ([UnitID], [UnitName]) VALUES (2, N'Unit-02')
INSERT [dbo].[UnitInf] ([UnitID], [UnitName]) VALUES (3, N'Unit-03')
INSERT [dbo].[UnitInf] ([UnitID], [UnitName]) VALUES (4, N'Unit-04')
INSERT [dbo].[UnitInf] ([UnitID], [UnitName]) VALUES (5, N'Unit-05')
SET IDENTITY_INSERT [dbo].[UnitInf] OFF
/****** Object: Table [dbo].[Section] Script Date: 05/11/2017 21:19:34 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Section](
[secId] [int] IDENTITY(1,1) NOT NULL,
[SecName] [nvarchar](100) NULL,
[UnitName] [int] NULL,
CONSTRAINT [PK_Section] PRIMARY KEY CLUSTERED
(
[secId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET IDENTITY_INSERT [dbo].[Section] ON
INSERT [dbo].[Section] ([secId], [SecName], [UnitName]) VALUES (1, N'B-001', 1)
INSERT [dbo].[Section] ([secId], [SecName], [UnitName]) VALUES (2, N'C-001', 2)
INSERT [dbo].[Section] ([secId], [SecName], [UnitName]) VALUES (3, N'B-002', 1)
INSERT [dbo].[Section] ([secId], [SecName], [UnitName]) VALUES (4, N'D-004', 4)
SET IDENTITY_INSERT [dbo].[Section] OFF
/****** Object: Table [dbo].[EmpInf] Script Date: 05/11/2017 21:19:34 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[EmpInf](
[EmpId] [int] IDENTITY(1,1) NOT NULL,
[DeptId] [int] NULL,
[SecID] [int] NULL,
[EmpName] [nvarchar](100) NULL,
[GrossSal] [float] NULL,
[Desg] [nvarchar](100) NULL,
[SkillBonus] [float] NULL,
[Active] [nvarchar](10) NULL,
[JoinDate] [datetime] NULL,
CONSTRAINT [PK_EmpInf] PRIMARY KEY CLUSTERED
(
[EmpId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET IDENTITY_INSERT [dbo].[EmpInf] ON
INSERT [dbo].[EmpInf] ([EmpId], [DeptId], [SecID], [EmpName], [GrossSal], [Desg], [SkillBonus], [Active], [JoinDate]) VALUES (1, 2, 2, N'John', 10000, N'Operator', 2000, N'Active', CAST(0x0000A59F00000000 AS DateTime))
INSERT [dbo].[EmpInf] ([EmpId], [DeptId], [SecID], [EmpName], [GrossSal], [Desg], [SkillBonus], [Active], [JoinDate]) VALUES (2, 2, 2, N'Jack', 12000, N'Operator', 5000, N'Active', CAST(0x0000A5BC00000000 AS DateTime))
INSERT [dbo].[EmpInf] ([EmpId], [DeptId], [SecID], [EmpName], [GrossSal], [Desg], [SkillBonus], [Active], [JoinDate]) VALUES (3, 2, 4, N'Nick', 14000, N'Jr. Operator', 6000, N'Active', CAST(0x0000A75100000000 AS DateTime))
INSERT [dbo].[EmpInf] ([EmpId], [DeptId], [SecID], [EmpName], [GrossSal], [Desg], [SkillBonus], [Active], [JoinDate]) VALUES (4, 2, 4, N'Bruce', 15000, N'Operator', 7000, N'Active', CAST(0x0000A79000000000 AS DateTime))
INSERT [dbo].[EmpInf] ([EmpId], [DeptId], [SecID], [EmpName], [GrossSal], [Desg], [SkillBonus], [Active], [JoinDate]) VALUES (5, 2, 1, N'Willy', 16000, N'Jr. Operator', 8000, N'Active', CAST(0x0000A7B800000000 AS DateTime))
SET IDENTITY_INSERT [dbo].[EmpInf] OFF
/****** Object: Table [dbo].[Department] Script Date: 05/11/2017 21:19:34 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Department](
[DeptId] [int] IDENTITY(1,1) NOT NULL,
[DeptName] [nvarchar](100) NULL,
CONSTRAINT [PK_Department] PRIMARY KEY CLUSTERED
(
[DeptId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET IDENTITY_INSERT [dbo].[Department] ON
INSERT [dbo].[Department] ([DeptId], [DeptName]) VALUES (1, N'Admin')
INSERT [dbo].[Department] ([DeptId], [DeptName]) VALUES (2, N'Production')
SET IDENTITY_INSERT [dbo].[Department] OFF

Answer 1

I think that simple conditional aggregation is the best approach:
SELECT o.UnitName, p.DeptName, COUNT(m.EmpId) AS cnt,
SUM(CASE WHEN DATEDIFF(MONTH, m.Joindate, GETDATE()) BETWEEN 0 AND 6
THEN 1 ELSE 0
END) AS [0 - 6 Months]
FROM EmpInf m INNER JOIN
Department k
ON k.DeptId = m.DeptId INNER JOIN
Section l
ON l.secId = m.SecID INNER JOIN
UnitInf o
ON o.UnitID = l.UnitName INNER JOIN
Department p
ON p.DeptId = m.DeptId
WHERE Desg IN ('Jr. Operator', 'Operator') AND Active = 'Active' AND
p.DeptName = 'Production'
GROUP BY o.UnitName, p.DeptName

Answer 2

I haven't run your code, but it looks like you're hardcoding too much in your subquery.
(SELECT COUNT(m.EmpId) FROM EmpInf m
WHERE m.Desg IN ('Jr. Operator', 'Operator') AND m.Active = 'Active' AND m.DeptId = 2
AND DATEDIFF(MONTH, m.Joindate, GETDATE()) BETWEEN 0 AND 6) AS '0 - 6 Months'
Problem 1: your alias for EmpInf in the subquery is "m" and your alias for EmpInf in your main query is "m". Make them different so you can link them.
Problem 2: Connect your variables in the subquery to values in the main query. So:
(SELECT COUNT(m.EmpId) FROM EmpInf subm
WHERE subm.Desg=m.Desg AND subm.Active = m.Active AND subm.DeptId = m.DeptId
AND DATEDIFF(MONTH, subm.Joindate, GETDATE()) BETWEEN 0 AND 6) AS '0 - 6 Months'