SQLite Helper (C#) z

http://www.codeproject.com/Articles/746191/SQLite-Helper-Csharp

Introduction

I have written a small class, SQLiteHelper which aims to simplify the usage of SQLite in C#.

Prerequisite

This small class is built on top of System.Data.SQLite.DLL. A reference of this DLL must be added into your projects.

Download: https://system.data.sqlite.org

List of Simplified Functions

1. GetTableStatus
2. GetColumnStatus
3. CreateTable
4. BeginTransaction, Commit, Rollback
5. Select
6. Execute
7. ExecuteScalar
8. ExecuteScalarStr
9. ExecuteScalarInt
10. ExecuteScalarDateTime
11. ExecuteScalarDecimal
12. ExecuteScalarBlob
13. Escape
14. Insert
15. Update
16. RenameTable
17. CopyAllData
18. DropTable

Getting Start

Add this using statement at the top of your class:

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using System.Data.SQLite;

SQLiteConnection and SQLiteCommand have to be initialized before using SQLiteHelper:

Example:

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using (SQLiteConnection conn = new SQLiteConnection("data source=C:\data"))
{
    using (SQLiteCommand cmd = new SQLiteCommand())
    {
        cmd.Connection = conn;
        conn.Open();
 
        SQLiteHelper sh = new SQLiteHelper(cmd);
 
        // do something...

        conn.Close();
    }
}

1. GetTableStatus

Get all information of tables in the database.

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DataTable dt = sh.GetTableStatus();

2. GetColumnStatus

Get all information of columns in specific table.

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// Get column's information from table "person"
DataTable dt = sh.GetColumnStatus("person");

3. CreateTable

Create table.

Example table structure: Person

Column Name	Data Type	Primary Key	Not Null	Default Value
id	int	true
name	text
membershipid	int
level	decimal			5.5

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SQLiteTable tb = new SQLiteTable("person");
 
tb.Columns.Add(new SQLiteColumn("id", true));
tb.Columns.Add(new SQLiteColumn("name"));
tb.Columns.Add(new SQLiteColumn("membershipid", ColType.Integer));
tb.Columns.Add(new SQLiteColumn("level", ColType.Decimal, false, false, "5.5"));
 
sh.CreateTable(tb);

4. BeginTransaction, Commit, Rollback

Applying transactions.

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sh.BeginTransaction();
 
try
{
    // execute some queries

    sh.Commit();
}
catch
{
    sh.Rollback();
}

5. Select

Return the query result in DataTable format.

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DataTable dt = sh.Select("select * from person order by id;");

6. Execute

Execute single SQL query.

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sh.Execute("insert into person(name)values('hello');");

7. ExecuteScalar

Return the result from first row first column in object format.

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object ob = sh.ExecuteScalar("select max(id) from person;");

8. ExecuteScalarStr

Return the result from first row first column in string format.

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string s = sh.ExecuteScalarStr("select max(id) from person;");

9. ExecuteScalarInt

Return the result from first row first column in Int format.

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int i = sh.ExecuteScalarInt("select max(id) from person;");

10. ExecuteScalarDateTime

Return the result from first row first column in DateTime format.

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DateTime date = sh.ExecuteScalarDateTime("select dateregister from person where id = 1;");

11. ExecuteScalarDecimal

Return the result from first row first column in decimal format.

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decimal d = sh.ExecuteScalarDecimal("select level from person where id = 1;");

12. ExecuteScalarBlob

Return the result from first row first column in byte[] format.

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byte[] ba = sh.ExecuteScalarBlob("select photo from person where id = 1;");

13. Escape

Escape string sequence for text value to avoid SQL injection or invalid SQL syntax to be constructed.

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string value = sh.Escape(input);

14. Insert

Insert data.

Sample 1: Insert single row.

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var dic = new Dictionary<string, object>();
dic["name"] = "John";
dic["membershipid"] = 1;
dic["level"] = 6.8;
 
sh.Insert("person", dic);

Sample 2: Insert multiple rows.

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var lst = new List<Dictionary<string,>();
 
var dic1 = new Dictionary<string,>();
dic1["name"] = "John";
dic1["membershipid"] = 1;
dic1["level"] = 6.8;
lst.Add(dic1);
 
var dic2 = new Dictionary<string,>();
dic2["name"] = "Catherine";
dic2["membershipid"] = 2;
dic2["level"] = 9.7;
lst.Add(dic2);
 
var dic3 = new Dictionary<string,>();
dic3["name"] = "Thomas";
dic3["membershipid"] = 3;
dic3["level"] = 8.6;
lst.Add(dic3);
 
sh.Insert("person", lst);

16. Update

Update row.

Sample 1: Update with single condition (where id = 1)

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var dicData = new Dictionary<string, object>();
dicData["name"] = "no name";
dicData["membershipid"] = 0;
dicData["level"] = 5.5;
 
sh.Update("person", dicData, "id", 1);

Sample 2: Update with multiple condition (where membership = 1 and level = 5.5)

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var dicData = new Dictionary<string, object>();
dicData["name"] = "no name";
dicData["status"] = 0;
dicData["money"] = 100;
dicData["dateregister"] = DateTime.MinValue;
 
var dicCondition = new Dictionary<string,>();
dicCondition["membershipid"] = 1;
dicData["level"] = 5.5;
 
sh.Update("person", dicData, dicCondition);

16. RenameTable

Rename a table.

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sh.RenameTable("person", "person_backup");

17. CopyAllData

Copy all data from one table to another.

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sh.CopyAllData("person", "person_new");

Before copying, SQLiteHelper will scan the two tables for match columns. Only columns that exist in both tables will be copied.

18. DropTable

Drop table, delete a table

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sh.DropTable("person");

That's it, guys/girls. Comments are welcome.

Happy coding

Also available at: https://sh.codeplex.com/[^]