Implementato il supporto per la scoperta e la visualizzazione dello schema del database, inclusa la creazione di provider specifici per SQL Server e l'integrazione con il servizio di connessione al database.

2025-04-28 23:55:56 +02:00
parent 503b567fb7
commit d1103c4e7d
10 changed files with 546 additions and 79 deletions
@@ -0,0 +1,152 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Threading.Tasks;
+using DataConnection.Interfaces;
+using Microsoft.Data.SqlClient;
+
+namespace DataConnection.EF.SchemaProviders;
+
+/// <summary>
+/// Provider di schema per database SQL Server
+/// </summary>
+public class SqlServerSchemaProvider : IDatabaseSchemaProvider
+{
+    public async Task<IDictionary<string, IEnumerable<DbColumnInfo>>> GetDatabaseSchemaAsync(string connectionString)
+    {
+        var result = new Dictionary<string, IEnumerable<DbColumnInfo>>();
+        
+        try
+        {
+            using (var connection = new SqlConnection(connectionString))
+            {
+                await connection.OpenAsync();
+                
+                // Query per ottenere la struttura delle tabelle in SQL Server
+                string sql = @"
+                    SELECT 
+                        SCHEMA_NAME(t.schema_id) + '.' + t.name AS TableName,
+                        c.name AS ColumnName,
+                        tp.name AS DataType,
+                        c.max_length,
+                        c.precision,
+                        c.scale,
+                        c.is_nullable,
+                        CASE WHEN pk.column_id IS NOT NULL THEN 1 ELSE 0 END AS IsPrimaryKey,
+                        CASE WHEN fk.parent_column_id IS NOT NULL THEN 1 ELSE 0 END AS IsForeignKey,
+                        SCHEMA_NAME(ref_t.schema_id) + '.' + ref_t.name AS ReferencedTable,
+                        ref_c.name AS ReferencedColumn
+                    FROM 
+                        sys.tables t
+                    INNER JOIN 
+                        sys.columns c ON t.object_id = c.object_id
+                    INNER JOIN 
+                        sys.types tp ON c.user_type_id = tp.user_type_id
+                    LEFT JOIN 
+                        (SELECT 
+                            ic.object_id, 
+                            ic.column_id
+                         FROM 
+                            sys.indexes i
+                         INNER JOIN 
+                            sys.index_columns ic ON i.object_id = ic.object_id AND i.index_id = ic.index_id
+                         WHERE 
+                            i.is_primary_key = 1) pk ON t.object_id = pk.object_id AND c.column_id = pk.column_id
+                    LEFT JOIN 
+                        sys.foreign_key_columns fk ON t.object_id = fk.parent_object_id AND c.column_id = fk.parent_column_id
+                    LEFT JOIN 
+                        sys.tables ref_t ON fk.referenced_object_id = ref_t.object_id
+                    LEFT JOIN 
+                        sys.columns ref_c ON fk.referenced_object_id = ref_c.object_id AND fk.referenced_column_id = ref_c.column_id
+                    WHERE
+                        t.is_ms_shipped = 0
+                    ORDER BY 
+                        TableName, c.column_id";
+
+                using (var command = new SqlCommand(sql, connection))
+                {
+                    command.CommandType = CommandType.Text;
+                    
+                    using (var reader = await command.ExecuteReaderAsync())
+                    {
+                        string currentTable = null;
+                        List<DbColumnInfo> columns = null;
+                        
+                        while (await reader.ReadAsync())
+                        {
+                            string tableName = reader.GetString(0);
+                            
+                            // Se stiamo passando a una nuova tabella, aggiungiamo la tabella precedente e creiamo una nuova lista
+                            if (currentTable != tableName)
+                            {
+                                if (currentTable != null && columns != null && columns.Count > 0)
+                                {
+                                    result[currentTable] = columns;
+                                }
+                                
+                                currentTable = tableName;
+                                columns = new List<DbColumnInfo>();
+                            }
+                            
+                            // Formato del tipo di dati con precisione e scala per tipi numerici o lunghezza per tipi stringa
+                            string dataType = reader.GetString(2);
+                            int maxLength = reader.GetInt16(3);
+                            byte precision = reader.GetByte(4);
+                            byte scale = reader.GetByte(5);
+                            
+                            // Formattazione tipo di dati per SQL Server
+                            string formattedDataType = FormatSqlServerDataType(dataType, maxLength, precision, scale);
+                            
+                            var columnInfo = new DbColumnInfo
+                            {
+                                Name = reader.GetString(1),
+                                DataType = formattedDataType,
+                                IsNullable = reader.GetBoolean(6),
+                                IsPrimaryKey = reader.GetInt32(7) == 1,
+                                IsForeignKey = reader.GetInt32(8) == 1,
+                                ReferencedTable = reader.IsDBNull(9) ? null : reader.GetString(9),
+                                ReferencedColumn = reader.IsDBNull(10) ? null : reader.GetString(10)
+                            };
+                            
+                            columns?.Add(columnInfo);
+                        }
+                        
+                        // Aggiungiamo l'ultima tabella
+                        if (currentTable != null && columns != null && columns.Count > 0)
+                        {
+                            result[currentTable] = columns;
+                        }
+                    }
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Errore nel recupero dello schema del database SQL Server: {ex.Message}");
+            throw;
+        }
+        
+        return result;
+    }
+    
+    private static string FormatSqlServerDataType(string dataType, int maxLength, byte precision, byte scale)
+    {
+        string formattedDataType = dataType;
+        
+        if (dataType == "nvarchar" || dataType == "varchar" || dataType == "char" || dataType == "nchar")
+        {
+            if (maxLength == -1)
+                formattedDataType += "(MAX)";
+            else if (dataType.StartsWith("n")) // tipi Unicode - la lunghezza è in byte, dobbiamo dividerla per 2
+                formattedDataType += $"({maxLength / 2})";
+            else
+                formattedDataType += $"({maxLength})";
+        }
+        else if (dataType == "decimal" || dataType == "numeric")
+        {
+            formattedDataType += $"({precision},{scale})";
+        }
+        
+        return formattedDataType;
+    }
+}