protected override void ColumnDefinition()

in EFCore/src/Migrations/MySQLMigrationsSqlGenerator.cs [232:347]
98 lines of code
23 McCabe index (conditional complexity)

    protected override void ColumnDefinition(AddColumnOperation operation, IModel? model,
      MigrationCommandListBuilder builder)
      => ColumnDefinition(
        operation.Schema,
        operation.Table,
        operation.Name,
        operation,
        model,
        builder);

    /// <summary>
    ///   Generates a SQL fragment for a column definition for the given column metadata.
    /// </summary>
    /// <param name="schema"> The schema that contains the table, or <c>null</c> to use the default schema. </param>
    /// <param name="table"> The table that contains the column. </param>
    /// <param name="name"> The column name. </param>
    /// <param name="operation"> The column metadata. </param>
    /// <param name="model"> The target model, which may be <c>null</c> if the operations exist without a model. </param>
    /// <param name="builder"> The command builder to use to add the SQL fragment. </param>
    protected override void ColumnDefinition(
       string? schema,
       string table,
       string name,
       ColumnOperation operation,
       IModel? model,
       MigrationCommandListBuilder builder)
    {
      Check.NotEmpty(name, nameof(name));
      Check.NotNull(operation, nameof(operation));
      Check.NotNull(builder, nameof(builder));

      var matchType = operation.ColumnType ?? GetColumnType(schema, table, name, operation, model);
      var matchLen = "";
      var match = _typeRegex.Match(matchType ?? "-");
      if (match.Success)
      {
        matchType = match.Groups[1].Value.ToLower();
        if (!string.IsNullOrWhiteSpace(match.Groups[2].Value))
        {
          matchLen = match.Groups[2].Value;
        }
      }

      var valueGenerationStrategy = MySQLValueGenerationStrategyCompatibility.GetValueGenerationStrategy(operation.GetAnnotations().OfType<IAnnotation>().ToArray());

      var autoIncrement = false;
      if (valueGenerationStrategy == MySQLValueGenerationStrategy.IdentityColumn &&
        string.IsNullOrWhiteSpace(operation.DefaultValueSql) && operation.DefaultValue == null)
      {
        switch (matchType)
        {
          case "tinyint":
          case "smallint":
          case "mediumint":
          case "int":
          case "bigint":
            autoIncrement = true;
            break;
          case "datetime":
          case "timestamp":
            operation.DefaultValueSql = $"CURRENT_TIMESTAMP({matchLen})";
            break;
        }
      }

      string? onUpdateSql = null;
      if (operation.IsRowVersion || valueGenerationStrategy == MySQLValueGenerationStrategy.ComputedColumn)
      {
        switch (matchType)
        {
          case "datetime":
          case "timestamp":
            if (string.IsNullOrWhiteSpace(operation.DefaultValueSql) && operation.DefaultValue == null)
            {
              operation.DefaultValueSql = $"CURRENT_TIMESTAMP({matchLen})";
            }

            onUpdateSql = $"CURRENT_TIMESTAMP({matchLen})";
            break;
        }
      }

      if (operation.ComputedColumnSql == null)
      {
        ColumnDefinitionWithCharSet(schema, table, name, operation, model, builder);

        if (autoIncrement)
        {
          builder.Append(" AUTO_INCREMENT");
        }
        else
        {
          if (onUpdateSql != null)
          {
            builder
              .Append(" ON UPDATE ")
              .Append(onUpdateSql);
          }
        }
      }
      else
      {
        builder
          .Append(Dependencies.SqlGenerationHelper.DelimitIdentifier(name))
          .Append(" ")
          .Append(operation.ColumnType ?? GetColumnType(schema, table, name, operation, model));
        builder
          .Append(" AS ")
          .Append($"({operation.ComputedColumnSql})");

        if (operation.IsNullable)
        {
          builder.Append(" NULL");
        }
      }
    }