code: def upgrade():
      """Apply Fix description field in ``connection`` to be ``text``"""
      conn = op.get_bind()
      if conn.dialect.name == "sqlite":
          # in sqlite TEXT and STRING column types are the same
          return
      if conn.dialect.name == "mysql":
          op.alter_column(
              "connection",
              "description",
              existing_type=sa.String(length=5000),
              type_=sa.Text(length=5000),
              existing_nullable=True,
          )
      else:
          # postgres does not allow size modifier for text type
          op.alter_column(
              "connection",
              "description",
              existing_type=sa.String(length=5000),
              type_=sa.Text(),
          )
  
imports: from __future__ import annotations
  import sqlalchemy
  from alembic import op
label_desc: Use image node_id 1 for calling a global function with example usage: upgrade() without return types