fix(app): 修复 Oracle 表结构已有字段识别

Co-authored-by: staff <staff@qimaos-MacBook-Pro.local>

crates/dbx-core/src/table_structure_sql/columns.rs

@@ -20,6 +20,13 @@ pub(super) fn build_column_sql(options: &TableStructureSqlOptions, warnings: &mu
     let table = qualified_table(dialect, options.schema.as_deref(), &options.table_name);
     let database_label = database_label(options.database_type);
     let active_columns: Vec<_> = options.columns.iter().filter(|column| !column.marked_for_drop).collect();
+    if dialect == StructureDialect::Oracle
+        && active_columns.is_empty()
+        && options.columns.iter().any(|column| column.marked_for_drop)
+    {
+        warnings.push("Oracle does not allow dropping all columns from a table. Keep at least one column or drop the table instead.".to_string());
+        return Vec::new();
+    }
     let has_original_column_positions = active_columns.iter().any(|column| column.original_position.is_some());
     let mut simulated_column_order =
         if has_original_column_positions { original_active_column_order(&active_columns) } else { Vec::new() };

crates/dbx-core/src/table_structure_sql/tests.rs

@@ -246,6 +246,52 @@ fn builds_informix_column_and_index_changes() {
     );
 }
 
+#[test]
+fn oracle_does_not_generate_drop_sql_for_all_columns() {
+    let mut id = column("id");
+    id.marked_for_drop = true;
+    id.original = Some(ColumnInfo {
+        name: "id".to_string(),
+        data_type: "varchar2(255)".to_string(),
+        is_nullable: true,
+        column_default: None,
+        is_primary_key: false,
+        extra: None,
+        comment: None,
+    });
+    let mut name = column("name");
+    name.marked_for_drop = true;
+    name.original = Some(ColumnInfo {
+        name: "name".to_string(),
+        data_type: "varchar2(255)".to_string(),
+        is_nullable: true,
+        column_default: None,
+        is_primary_key: false,
+        extra: None,
+        comment: None,
+    });
+
+    let result = build_table_structure_change_sql(TableStructureSqlOptions {
+        database_type: Some(DatabaseType::Oracle),
+        schema: Some("DBX_TEST".to_string()),
+        table_name: "test".to_string(),
+        columns: vec![id, name],
+        indexes: Vec::new(),
+        foreign_keys: Vec::new(),
+        triggers: Vec::new(),
+        table_comment: None,
+        original_table_comment: None,
+    });
+
+    assert_eq!(result.statements, Vec::<String>::new());
+    assert_eq!(
+        result.warnings,
+        vec![
+            "Oracle does not allow dropping all columns from a table. Keep at least one column or drop the table instead."
+        ]
+    );
+}
+
 #[test]
 fn iris_drop_index_includes_table_name() {
     let mut old_index = index("index_id", &["ID"]);