fix(kingbase): restore table structure type parameters

apps/desktop/src/lib/table/tableStructureEditorState.ts

@@ -638,11 +638,30 @@ function columnDefaultForEditor(column: ColumnInfo, databaseType?: DatabaseType)
   return defaultValue;
 }
 
+const CHARACTER_LENGTH_METADATA_TYPES = new Set(["binary", "char", "character", "character varying", "nchar", "nvarchar", "nvarchar2", "varbinary", "varchar", "varchar2"]);
+const NUMERIC_PRECISION_METADATA_TYPES = new Set(["decimal", "number", "numeric"]);
+
+function columnDataTypeForEditor(column: ColumnInfo, databaseType?: DatabaseType): string {
+  const parsed = splitDataType(column.data_type);
+  if (parsed.params) return column.data_type;
+
+  const baseType = parsed.baseType.trim().replace(/\s+/g, " ");
+  const normalized = baseType.toLowerCase();
+  if (CHARACTER_LENGTH_METADATA_TYPES.has(normalized) && Number.isInteger(column.character_maximum_length) && Number(column.character_maximum_length) > 0) {
+    return combineDataTypeForDatabase(databaseType, baseType, String(column.character_maximum_length));
+  }
+  if (NUMERIC_PRECISION_METADATA_TYPES.has(normalized) && Number.isInteger(column.numeric_precision) && Number(column.numeric_precision) > 0) {
+    const scale = Number.isInteger(column.numeric_scale) && Number(column.numeric_scale) >= 0 ? `,${column.numeric_scale}` : "";
+    return combineDataTypeForDatabase(databaseType, baseType, `${column.numeric_precision}${scale}`);
+  }
+  return column.data_type;
+}
+
 export function createColumnDrafts(columns: ColumnInfo[], databaseType?: DatabaseType): EditableStructureColumn[] {
   return columns.map((column, index) => {
     const defaultValue = columnDefaultForEditor(column, databaseType);
     const enumValues = isMysqlEnumDataType(databaseType, column.data_type) ? [...(column.enum_values ?? [])] : undefined;
-    const dataType = enumValues?.length ? mysqlEnumDataType(enumValues) : column.data_type;
+    const dataType = enumValues?.length ? mysqlEnumDataType(enumValues) : columnDataTypeForEditor(column, databaseType);
     return {
       id: `existing:${column.name}`,
       name: column.name,