fix: refactor column mapping

CodeGenerator/CodeGenerator.cs

@@ -152,7 +152,6 @@ private string FindEnumSchema(Enum e)
                     return schemaTables.Key;
             }
         }
-        // TODO fix why not mapping default schema to string.Empty
         throw new InvalidDataException($"No enum {e.Name} schema found.");
     }
 

Drivers/ColumnMapping.cs

@@ -6,10 +6,8 @@ namespace SqlcGenCsharp.Drivers;
 public record DbTypeInfo(int? Length = null, string? NpgsqlTypeOverride = null);
 
 public class ColumnMapping(
-    string csharpType,
     Dictionary<string, DbTypeInfo> dbTypes, Func<int, string> readerFn, Func<int, string>? readerArrayFn = null)
 {
-    public string CsharpType { get; } = csharpType;
     public Func<int, string> ReaderFn { get; } = readerFn;
     public Func<int, string>? ReaderArrayFn { get; } = readerArrayFn;
     public Dictionary<string, DbTypeInfo> DbTypes { get; } = dbTypes;

Drivers/DbDriver.cs

@@ -44,7 +44,7 @@ public abstract class DbDriver
         "NpgsqlCircle"
     ];
 
-    protected abstract List<ColumnMapping> ColumnMappings { get; }
+    protected abstract Dictionary<string, ColumnMapping> ColumnMappings { get; }
 
     protected const string TransformQueryForSliceArgsImpl = """
            public static string TransformQueryForSliceArgs(string originalSql, int sliceSize, string paramName)
@@ -155,10 +155,10 @@ private string GetCsharpTypeWithoutNullableSuffix(Column column, Query? query)
         }
 
         foreach (var columnMapping in ColumnMappings
-                     .Where(columnMapping => DoesColumnMappingApply(columnMapping, column)))
+                     .Where(columnMapping => DoesColumnMappingApply(columnMapping.Value, column)))
         {
-            if (column.IsArray || column.IsSqlcSlice) return $"{columnMapping.CsharpType}[]";
-            return columnMapping.CsharpType;
+            if (column.IsArray || column.IsSqlcSlice) return $"{columnMapping.Key}[]";
+            return columnMapping.Key;
         }
 
         throw new NotSupportedException($"Column {column.Name} has unsupported column type: {column.Type.Name}");
@@ -186,7 +186,7 @@ private static bool DoesColumnMappingApply(ColumnMapping columnMapping, Column c
 
     private string GetColumnReader(OverrideOption overrideOption, int ordinal)
     {
-        var columnMapping = ColumnMappings.Find(c => c.CsharpType == overrideOption.CsharpType.Type);
+        var columnMapping = ColumnMappings.GetValueOrDefault(overrideOption.CsharpType.Type);
         if (columnMapping is not null)
             return columnMapping.ReaderFn(ordinal);
         throw new NotSupportedException($"Column {overrideOption.Column} has unsupported column type: {overrideOption.CsharpType.Type}");
@@ -207,7 +207,7 @@ public string GetColumnReader(Column column, int ordinal, Query? query)
                 return GetColumnReader(foundOverride, ordinal);
         }
 
-        foreach (var columnMapping in ColumnMappings
+        foreach (var columnMapping in ColumnMappings.Values
                      .Where(columnMapping => DoesColumnMappingApply(columnMapping, column)))
         {
             if (column.IsArray)
@@ -220,7 +220,7 @@ public string GetColumnReader(Column column, int ordinal, Query? query)
     protected string? GetColumnDbTypeOverride(Column column)
     {
         var columnType = column.Type.Name.ToLower();
-        foreach (var columnMapping in ColumnMappings)
+        foreach (var columnMapping in ColumnMappings.Values)
         {
             if (columnMapping.DbTypes.TryGetValue(columnType, out var dbTypeOverride))
                 return dbTypeOverride.NpgsqlTypeOverride;
@@ -240,10 +240,12 @@ public bool IsTypeNullable(string csharpType)
         return Options.DotnetFramework.IsDotnetCore(); // non-primitives in .Net Core are inherently nullable
     }
 
-    /*
-    Since there is no indication of the primary key column in SQLC protobuf (assuming it is a single column),
-    this method uses a few heuristics to assess the data type of the id column
-    */
+    /// <summary>
+    /// Since there is no indication of the primary key column in SQLC protobuf (assuming it is a single column),
+    /// this method uses a few heuristics to assess the data type of the id column
+    /// </summary>
+    /// <param name="query"></param>
+    /// <returns>The data type of the id column</returns>
     public string GetIdColumnType(Query query)
     {
         var tableColumns = Tables[query.InsertIntoTable.Schema][query.InsertIntoTable.Name].Columns;

Drivers/Generators/CommonGen.cs

@@ -92,7 +92,7 @@ public static string GetSqlTransformations(Query query, string queryTextConstant
                  """;
     }
 
-    public string InstantiateDataclass(Column[] columns, string returnInterface, Query? query)
+    public string InstantiateDataclass(Column[] columns, string returnInterface, Query query)
     {
         var columnsInit = new List<string>();
         var actualOrdinal = 0;
@@ -120,7 +120,7 @@ public string InstantiateDataclass(Column[] columns, string returnInterface, Que
 
         return InstantiateDataclassInternal(returnInterface, columnsInit);
 
-        string[] GetAsEmbeddedTableColumnAssignment(Column tableColumn, int ordinal, Query? query)
+        string[] GetAsEmbeddedTableColumnAssignment(Column tableColumn, int ordinal, Query query)
         {
             var schemaName = tableColumn.EmbedTable.Schema == dbDriver.DefaultSchema ? string.Empty : tableColumn.EmbedTable.Schema;
             var tableColumns = dbDriver.Tables[schemaName][tableColumn.EmbedTable.Name].Columns;

Drivers/MySqlConnectorDriver.cs

@@ -22,84 +22,106 @@ public partial class MySqlConnectorDriver(
     public const string ByteCsvConverter = "ByteCsvConverter";
     public const string ByteArrayCsvConverter = "ByteArrayCsvConverter";
 
-    protected override List<ColumnMapping> ColumnMappings { get; } =
-    [
-        new("bool",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "tinyint", new DbTypeInfo(Length: 1) }
-            }, ordinal => $"reader.GetBoolean({ordinal})"),
-        new("short",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "tinyint", new DbTypeInfo() },
-                { "smallint", new DbTypeInfo() },
-                { "year", new DbTypeInfo() }
-            }, ordinal => $"reader.GetInt16({ordinal})"),
-        new("long",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "bigint", new DbTypeInfo() }
-            }, ordinal => $"reader.GetInt64({ordinal})"),
-        new("byte",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "bit", new DbTypeInfo() }
-            }, ordinal => $"reader.GetFieldValue<byte>({ordinal})"),
-        new("byte[]",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "binary", new DbTypeInfo() },
-                { "blob", new DbTypeInfo() },
-                { "longblob", new DbTypeInfo() },
-                { "mediumblob", new DbTypeInfo() },
-                { "tinyblob", new DbTypeInfo() },
-                { "varbinary", new DbTypeInfo() }
-            }, ordinal => $"reader.GetFieldValue<byte[]>({ordinal})"),
-        new("string",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "char", new DbTypeInfo() },
-                { "longtext", new DbTypeInfo() },
-                { "mediumtext", new DbTypeInfo() },
-                { "text", new DbTypeInfo() },
-                { "time", new DbTypeInfo() },
-                { "tinytext", new DbTypeInfo() },
-                { "varchar", new DbTypeInfo() },
-                { "var_string", new DbTypeInfo() },
-                { "json", new DbTypeInfo() },
-            }, ordinal => $"reader.GetString({ordinal})"),
-        new("DateTime",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "date", new DbTypeInfo() },
-                { "datetime", new DbTypeInfo() },
-                { "timestamp", new DbTypeInfo() }
-            }, ordinal => $"reader.GetDateTime({ordinal})"),
-        new("int",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "int", new DbTypeInfo() },
-                { "mediumint", new DbTypeInfo() },
-            }, ordinal => $"reader.GetInt32({ordinal})"),
-        new("double",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "double", new DbTypeInfo() },
-                { "float", new DbTypeInfo() }
-            }, ordinal => $"reader.GetDouble({ordinal})"),
-        new("decimal",
-            new Dictionary<string, DbTypeInfo>
-            {
-                { "decimal", new DbTypeInfo() }
-            }, ordinal => $"reader.GetDecimal({ordinal})"),
-        // last item in the dictionary - enforce TODO
-        new("object",
+    protected override Dictionary<string, ColumnMapping> ColumnMappings { get; } =
+        new()
+        {
+            ["bool"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "tinyint", new DbTypeInfo(Length: 1) }
+                },
+                ordinal => $"reader.GetBoolean({ordinal})"
+            ),
+            ["short"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "tinyint", new DbTypeInfo() },
+                    { "smallint", new DbTypeInfo() },
+                    { "year", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetInt16({ordinal})"
+            ),
+            ["long"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "bigint", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetInt64({ordinal})"
+            ),
+            ["byte"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "bit", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetFieldValue<byte>({ordinal})"
+            ),
+            ["byte[]"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "binary", new DbTypeInfo() },
+                    { "blob", new DbTypeInfo() },
+                    { "longblob", new DbTypeInfo() },
+                    { "mediumblob", new DbTypeInfo() },
+                    { "tinyblob", new DbTypeInfo() },
+                    { "varbinary", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetFieldValue<byte[]>({ordinal})"
+            ),
+            ["string"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "char", new DbTypeInfo() },
+                    { "longtext", new DbTypeInfo() },
+                    { "mediumtext", new DbTypeInfo() },
+                    { "text", new DbTypeInfo() },
+                    { "time", new DbTypeInfo() },
+                    { "tinytext", new DbTypeInfo() },
+                    { "varchar", new DbTypeInfo() },
+                    { "var_string", new DbTypeInfo() },
+                    { "json", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetString({ordinal})"
+            ),
+            ["DateTime"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "date", new DbTypeInfo() },
+                    { "datetime", new DbTypeInfo() },
+                    { "timestamp", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetDateTime({ordinal})"
+            ),
+            ["int"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "int", new DbTypeInfo() },
+                    { "mediumint", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetInt32({ordinal})"
+            ),
+            ["double"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "double", new DbTypeInfo() },
+                    { "float", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetDouble({ordinal})"
+            ),
+            ["decimal"] = new ColumnMapping(
+                new Dictionary<string, DbTypeInfo>
+                {
+                    { "decimal", new DbTypeInfo() }
+                },
+                ordinal => $"reader.GetDecimal({ordinal})"
+            ),
+            ["object"] = new ColumnMapping(
                 new Dictionary<string, DbTypeInfo>
                 {
                     { "any", new DbTypeInfo() }
-                }, ordinal => $"reader.GetValue({ordinal})")
-    ];
+                },
+                ordinal => $"reader.GetValue({ordinal})"
+            )
+        };
 
     public override UsingDirectiveSyntax[] GetUsingDirectivesForQueries()
     {