Feature/mutil embedding model (#908)

Co-authored-by: JzoNg <jzongcode@gmail.com>
Co-authored-by: jyong <jyong@dify.ai>
Co-authored-by: StyleZhang <jasonapring2015@outlook.com>

api/migrations/versions/2c8af9671032_add_qa_document_language.py

@@ -0,0 +1,32 @@
+"""add_qa_document_language
+
+Revision ID: 2c8af9671032
+Revises: 8d2d099ceb74
+Create Date: 2023-08-01 18:57:27.294973
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '2c8af9671032'
+down_revision = '5022897aaceb'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('documents', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('doc_language', sa.String(length=255), nullable=True))
+
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('documents', schema=None) as batch_op:
+        batch_op.drop_column('doc_language')
+
+    # ### end Alembic commands ###