drop-index command and table.drop_index(index_name)

Closes #626

sqlite_utils/cli.py

@@ -692,6 +692,34 @@ def create_index(
     )
 
 
+@cli.command(name="drop-index")
+@click.argument(
+    "path",
+    type=click.Path(exists=True, file_okay=True, dir_okay=False, allow_dash=False),
+    required=True,
+)
+@click.argument("table")
+@click.argument("index")
+@click.option("--ignore", help="Ignore if index does not exist", is_flag=True)
+@load_extension_option
+def drop_index(path, table, index, ignore, load_extension):
+    """
+    Drop an index by index name from the specified table
+
+    Example:
+
+    \b
+        sqlite-utils drop-index chickens.db chickens idx_chickens_name
+    """
+    db = sqlite_utils.Database(path)
+    _register_db_for_cleanup(db)
+    _load_extensions(db, load_extension)
+    try:
+        db.table(table).drop_index(index, ignore=ignore)
+    except OperationalError as ex:
+        raise click.ClickException(str(ex))
+
+
 @cli.command(name="enable-fts")
 @click.argument(
     "path",

sqlite_utils/db.py

@@ -3080,6 +3080,22 @@ class Table(Queryable):
             self.db.analyze(created_index_name)
         return self
 
+    def drop_index(self, index_name: str, ignore: bool = False):
+        """
+        Drop an index on this table.
+
+        :param index_name: Name of the index to drop
+        :param ignore: Set to ``True`` to ignore the error if the index does not exist
+        """
+        if index_name not in {index.name for index in self.indexes}:
+            if ignore:
+                return self
+            raise OperationalError(
+                "No index named {} on table {}".format(index_name, self.name)
+            )
+        self.db.execute("DROP INDEX {}".format(quote_identifier(index_name)))
+        return self
+
     def add_column(
         self,
         col_name: str,