昨天幫朋友做了個(gè)小工具,以完成多表連接處理一些數(shù)據(jù)。今天下班后又做了份使用文檔,不知友能看懂否?現(xiàn)將使用文檔及源碼發(fā)布如下,以供有同樣需求的朋友下載。
INSERT INTO [Employee$](EmployeeId,EmployeeName,BranchId) VALUES('YG2014120001','韓兆新','BM20141201');執(zhí)行Sql前:

執(zhí)行Sql后:

UPDATE [Employee$] SET BranchId = 'BM20141202';
執(zhí)行Sql前:

執(zhí)行Sql后:

SELECT EmployeeId,EmployeeName,BranchId FROM [Employee$];


顯然不支持!
UPDATE [Employee$] SET EmployeeID=null,EmployeeName=null,BranchId=null WHERE EmployeeID='YG2014120003';
執(zhí)行Sql前:

執(zhí)行Sql后:

SELECT EmployeeId,EmployeeName,BranchId FROM [Employee$] WHERE EmployeeID = 'YG2014120002';

SELECT * FROM [Employee$] WHERE EmployeeID LIKE 'YG201412%';

1、*:所有列的名稱(chēng);
2、%:通配n個(gè)字符;
3、_:通配1個(gè)字符。
1、升序:(ASC)可省略;
2、降序:(DSEC)。
示例1:(升序排序)
SELECT * FROM [Employee$] ORDER BY EmployeeId DESC;

示例2:(降序排序)
SELECT * FROM [Employee$] ORDER BY EmployeeId DESC;

示例3:(升序排序簡(jiǎn)寫(xiě))
SELECT * FROM [Employee$] ORDER BY EmployeeId;

先建立兩個(gè)用于演示的sheet:
Characters:
| ID | Character |
| 1 | 內(nèi)向 |
| 2 | 外向 |
| 3 | 中性性格 |
Colors:
| ID | Color |
| 1 | 綠色 |
| 2 | 紅色 |
| 4 | 藍(lán)色 |
內(nèi)連接(JOIN 或 INNER JOIN):內(nèi)連接取交集
示意圖:

SELECT * FROM [characters$] INNER JOIN [colors$] ON [characters$].ID = [colors$].ID;

外連接可分為:左連接、右連接、完全外連接。
示意圖:

SELECT * FROM [characters$] LEFT JOIN [colors$] ON [characters$].ID = [colors$].ID;
結(jié)果:

示意圖:

SELECT * FROM [characters$] RIGHT JOIN [colors$] ON [characters$].ID = [colors$].ID;
結(jié)果:

示意圖:

SELECT * FROM [characters$] LEFT JOIN [colors$] ON [characters$].ID = [colors$].ID
UNION
SELECT * FROM [characters$] RIGHT JOIN [colors$] ON [characters$].ID = [colors$].ID;
結(jié)果:

交叉連接產(chǎn)生連接所涉及的表的笛卡爾積。
SELECT * FROM [characters$],[colors$];
結(jié)果:

SELECT * FROM [characters$],[colors$] WHERE [characters$].ID = [colors$].ID;
SELECT * FROM [characters$],[colors$];
PRogram.cs
using System;
using System.IO;
using System.Windows.Forms;
namespace SqlExcel
{static class Program
{/// <summary>
/// 應(yīng)用程序的主入口點(diǎn)。
/// </summary>
[STAThread]
static void Main()
{Sunisoft.IrisSkin.SkinEngine skinEngine = new Sunisoft.IrisSkin.SkinEngine();
string skinPath = application.StartupPath + Path.DirectorySeparatorChar + "skin" + Path.DirectorySeparatorChar + "skin.ssk";
skinEngine.SkinFile = skinPath;
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new MainForm());
}
}
}
MainForm.cs
using System;
using System.Data;
using System.Data.Common;
using System.Drawing;
using System.Windows.Forms;
namespace SqlExcel
{
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