C ＃ use SQLite

SQLite Is a lightweight embedded database in process , Its database is a file , Self sufficiency has been achieved 、 There is no server 、 Zero configuration 、 transactional SQL Database engine . It is a zero-configuration database , That's what it's all about SQLite The biggest difference from other databases ：SQLite It does not need to be configured in the system , Directly available . And SQLite It's not an independent process , You can connect statically or dynamically according to your application requirements .SQLite You can directly access its storage files .

1. install ：System.Data.SQLite Components

2. Create data table

First, you need to create a table in the data , To add data , Only when there is data can the query be demonstrated , Modification and deletion .

Create a Person surface .

string dbfile = @"URI=file:sql.db";
SQLiteConnection cnn = new SQLiteConnection(dbfile);
cnn.Open();

string sql = "Create table Person (Id integer primary key, Name text);";
SQLiteCommand cmd = new SQLiteCommand(sql, cnn);
cmd.ExecuteNonQuery();
cnn.Close();

3. Add row data

string dbfile = @"URI=file:sql.db";
SQLiteConnection cnn = new SQLiteConnection(dbfile);
cnn.Open();

string sql = "insert into Person (Id , Name) values(1,'Mike');";
SQLiteCommand cmd = new SQLiteCommand(sql, cnn);
cmd.ExecuteNonQuery();
cnn.Close();

Console.WriteLine("Insert row OK");

4. Query data

string dbfile = @"URI=file:sql.db";

SQLiteConnection cnn = new SQLiteConnection(dbfile);

cnn.Open();

string sql = "Select * From Person";

SQLiteCommand cmd = new SQLiteCommand(sql, cnn);

SQLiteDataReader reader = cmd.ExecuteReader();

while(reader.Read())

{
    

  Console.WriteLine($"{
      reader.GetInt32(0)} {
      reader.GetString(1)} ");

}

reader.Close();

cnn.Close();

5. Update data

string dbfile = @"URI=file:sql.db";
SQLiteConnection cnn = new SQLiteConnection(dbfile);
cnn.Open();

string sql = "update Person set Name='Jim jones' where id=1;";
SQLiteCommand cmd = new SQLiteCommand(sql, cnn);
cmd.ExecuteNonQuery();
cnn.Close();

Console.WriteLine("Update row OK");

6. Delete data

string dbfile = @"URI=file:sql.db";
SQLiteConnection cnn = new SQLiteConnection(dbfile);
cnn.Open();

string sql = "delete from Person where id=3;";
SQLiteCommand cmd = new SQLiteCommand(sql, cnn);
cmd.ExecuteNonQuery();
cnn.Close();
Console.WriteLine("Delete row OK");

Basic data operation is realized , Additions and deletions . It can be used with a little modification in daily application .