comments, feature | Added new methods and comments that describe work of DatabaseWrapper

DatabaseWrapper.cs

@@ -2,10 +2,23 @@ using Microsoft.Data.Sqlite;
 
 namespace RestySqlite
 {
+    /** 
+    <summary>
+        Structure that represents SQL command injection parameter
+    </summary>
 
+    <example>
+    <code>
+        string insertSql = "INSERT INTO users (name) VALUES (@name)";
+
+        db.ExecuteCommand(insertSql, new Parameter("@name", "John Doe");
+    </code>
+    </example>
+    **/ 
     public struct Parameter
     {
         public string Name;
+        // Dynamic allows passing any type in db. Warning! type must be supported by db.
         public dynamic Value;
 
         public Parameter(string name, dynamic value)
@@ -14,12 +27,21 @@ namespace RestySqlite
             Value = value;
         }
     }
-
+    /**
+    <summary>
+        Class that wraps around database with automatic connection managment and handy tools.
+    </summary>
+    */
     public class DatabaseWrapper
     {
-        public SqliteConnection Connection {get; set;}
+        public SqliteConnection Connection {get;}
         public string DatabaseName {get; set; }
 
+        /**
+        <summary>
+            Construct a database wrapper around provided database.
+        </summary>
+        **/
         public DatabaseWrapper(string databaseName)
         {
             string connectionString = $"Data Source={databaseName}.db;";
@@ -30,11 +52,16 @@ namespace RestySqlite
 
         }
 
+        /**
+        <summary>
+            Execute SQL command with provided parameters.
+        </summary>
+        **/
         public void ExecuteCommand(string sqlCommand, params Parameter[] parameters)
         {
             Connection.Open();
             SqliteCommand comm = new(sqlCommand, Connection);
-            
+            // Handling parameters by passing each in command.
             if (parameters.Length != 0)
             {
                 foreach (Parameter param in parameters)
@@ -44,8 +71,15 @@ namespace RestySqlite
             }
 
             comm.ExecuteNonQuery();
+
+            Connection.Close();
         }
 
+        /**
+        <summary>
+            Execute SQL command with provided parameters and get reader from database.
+        </summary>
+        **/
         public SqliteDataReader? GetReader(string sqlCommand, params Parameter[] parameters)
         {
             Connection.Open();
@@ -60,16 +94,36 @@ namespace RestySqlite
             }
 
             var reader = comm.ExecuteReader();
+            
             return reader;
         }
 
+        /**
+        <summary>
+        Tool that parses entire database and returns all tables inside it.
+
+        <exception cref="NullReferenceException">
+            Throws NullReferenceException when reader is null for some reason.
+        </exception>
+
+        <example>
+        <code>
+            // For example:
+            var db = new DatabaseWrapper("example");
+            var tables = db.MapTables();
+            tables.ForEach(table => Console.WriteLine(table));
+        </code>
+        </example>
+        </summary>
+        **/
         public List<string> MapTables()
         {
-            var reader = this.GetReader(@"
+            var reader = GetReader(@"
                 SELECT *
                 FROM sqlite_master
                 WHERE type='table'
             ");
+            if (reader == null) throw new NullReferenceException("Reader is null");
 
             List<string> tables = new();
             using (reader)
@@ -83,14 +137,35 @@ namespace RestySqlite
 
             return tables;
         }
+        /**
+        <summary>
+        Tool that parses entire database and returns dictionary.
 
+        Where table name is its <c>Key</c> and List of columns attached to this table is its <c>Value</c>.
+        
+        <exception cref="NullReferenceException">
+            Throws NullReferenceException when reader is null for some reason.
+        </exception>
+
+        <example>
+        <code>
+            // For example:
+            var db = new DatabaseWrapper("example");
+            var tableColumns = db.MapColumns();
+            tables.ForEach(table => Console.WriteLine($"{table.Key} table {table.Value} list of collumns"));
+        </code>
+        </example>
+        </summary>
+        **/
         public Dictionary<string, List<string>> MapColumns()
         {
             Dictionary<string, List<string>> columnMap = new();
-            var tables = this.MapTables();
+            var tables = MapTables();
             foreach (string table in tables)
             {
-                var reader = this.GetReader($"pragma table_info({table});");
+                var reader = GetReader($"pragma table_info({table});");
+
+                if (reader == null) throw new NullReferenceException("Reader is null");
 
                 using (reader)
                 {
@@ -106,35 +181,53 @@ namespace RestySqlite
                     }
                 }
             }
+            return columnMap;
+        }
 
-            foreach (var table in columnMap)
+        /**
+        <summary>
+        Tool that parses provided table and column.
+        <returns>
+        After execution it returns list of values inside provided column.
+        </returns>
+        
+        <exception cref="NullReferenceException">
+            Throws NullReferenceException when reader is null for some reason.
+        </exception>
+
+        <example>
+        <code>
+            // For example:
+            var db = new DatabaseWrapper("example");
+            var usersnames = db.MapColumn("name", "users");
+
+            usernames.ForEach(name => Console.WriteLine(name));
+        </code>
+        </example>
+        </summary>
+        **/
+        public List<string>? MapColumn(string columnName, string tableName)
+        {
+            var reader = GetReader($"SELECT {columnName} FROM {tableName}");
+            // Using string. Because I cant know exactly which datatype I will encounter.
+            List<string> result = new();
+            
+            if (reader == null) throw new NullReferenceException("Reader is null");
+
+            using (reader)
             {
-                Console.WriteLine($"{table.Key}\n--------");
+                while (reader.Read())
-
-                foreach (var column in table.Value)
                 {
-                    var reader = this.GetReader($"SELECT {column} FROM {table.Key}");
+                    result.Add(reader.GetString(0));
-                    Console.WriteLine(column);
-                    try
-                    {
-                        while (reader.Read())
-                        {
-                            Console.WriteLine(reader.GetString(0));
-                        }
-                        Console.WriteLine("---------");
-                    }
-                    catch (Exception e)
-                    {
-                        Console.WriteLine($"Something broken: {e.Message}");
-                    }
-                    
                 }
             }
-            return columnMap;
+
+            return result;
         }
 
         ~DatabaseWrapper()
         {  
+            // Making sure that connection is closed.
             Connection.Close();
             Console.WriteLine($"Disconected from {DatabaseName}");
         }

WebApi.cs

@@ -6,16 +6,19 @@ namespace RestySqlite
         {
             DatabaseWrapper db = new("test");
 
-            /* string createTableSql = "CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY, name TEXT, email TEXT)";
+            //string createTableSql = "CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY, name TEXT, email TEXT)";
-            string insertSql = "INSERT INTO users (name, email) VALUES (@name, @email)";
+            /* string insertSql = "INSERT INTO users (name, email) VALUES (@name, @email)";
             
 
-            db.ExecuteCommand(createTableSql);
+            db.ExecuteCommand(insertSql, new Parameter("@name", "Max Nullov"), 
-            db.ExecuteCommand(insertSql, new Parameter("@name", "John Doe"), 
                 new Parameter("@email", "[not specified]"));
              */
             
             db.MapColumns();
+
+            var usersnames = db.MapColumn("name", "users");
+
+            usersnames.ForEach(name => Console.WriteLine(name));
         }   
     }
 }