Explain DuckDB query errors that abort the transaction (#1341)

src/python/txtai/database/duckdb.py

@@ -18,6 +18,7 @@ except ImportError:
 
 from .embedded import Embedded
 from .schema import Statement
+from .sql import SQLError
 
 
 class DuckDB(Embedded):
@@ -29,6 +30,11 @@ class DuckDB(Embedded):
     DELETE_DOCUMENT = "DELETE FROM documents WHERE id = ?"
     DELETE_OBJECT = "DELETE FROM objects WHERE id = ?"
 
+    # Added to errors that abort the transaction
+    ABORTED = (
+        "This error aborted the DuckDB transaction. Unsaved changes are lost and later operations fail until the index is loaded or built again."
+    )
+
     def __init__(self, config):
         super().__init__(config)
 
@@ -36,8 +42,15 @@ class DuckDB(Embedded):
             raise ImportError('DuckDB is not available - install "database" extra to enable')
 
     def execute(self, function, *args):
-        # Call parent method with DuckDB compatible arguments
-        return super().execute(function, *self.formatargs(args))
+        try:
+            # Call parent method with DuckDB compatible arguments
+            return super().execute(function, *self.formatargs(args))
+        except SQLError as e:
+            # Runtime errors abort the transaction. DuckDB has no savepoints, so it can't be recovered without a rollback.
+            if self.aborted():
+                raise SQLError(f"{e}\n\n{DuckDB.ABORTED}") from None
+
+            raise
 
     def insertdocument(self, uid, data, tags, entry):
         # Delete existing document
@@ -123,6 +136,20 @@ class DuckDB(Embedded):
 
         return connection
 
+    def aborted(self):
+        """
+        Checks if the current transaction is aborted.
+
+        Returns:
+            True if the current transaction is aborted
+        """
+
+        try:
+            self.connection.execute("SELECT 1")
+            return False
+        except duckdb.TransactionException:
+            return True
+
     def formatargs(self, args):
         """
         DuckDB doesn't support named parameters. This method replaces named parameters with question marks

test/python/testdatabase/testduckdb.py

@@ -5,6 +5,7 @@ DuckDB module tests
 import os
 import unittest
 
+from txtai.database import DuckDB, SQLError
 from txtai.embeddings import Embeddings
 
 from .testrdbms import Common
@@ -45,6 +46,28 @@ class TestDuckDB(Common.TestRDBMS):
         if cls.embeddings:
             cls.embeddings.close()
 
+    def testAborted(self):
+        """
+        Test SQL errors that abort the transaction
+        """
+
+        embeddings = Embeddings(keyword=True, content=self.backend)
+        embeddings.index([(0, "apple pie", None), (1, "banana bread", None)])
+
+        # Catalog errors don't abort the transaction
+        with self.assertRaises(SQLError) as context:
+            embeddings.search("select id from txtai where unknownfn(text)")
+
+        self.assertNotIn(DuckDB.ABORTED, str(context.exception))
+
+        # Runtime errors abort the transaction
+        with self.assertRaises(SQLError) as context:
+            embeddings.search("select id from txtai where text = :x", parameters={"x": 1})
+
+        self.assertIn("This error aborted the DuckDB transaction.", str(context.exception))
+
+        embeddings.close()
+
     @unittest.skipIf(os.name == "nt", "testArchive skipped on Windows")
     def testArchive(self):
         """