def change_column_nullable(table_oid, column_index, nullable, engine):
table = tables.reflect_table_from_oid(table_oid, engine)
column = table.columns[column_index]
with engine.begin() as conn:
ctx = MigrationContext.configure(conn)
op = Operations(ctx)
op.alter_column(table.name,
column.name,
nullable=nullable,
schema=table.schema)
return tables.reflect_table_from_oid(table_oid,
engine).columns[column_index]
def retype_column(table_oid, column_index, new_type, engine):
table = tables.reflect_table_from_oid(table_oid, engine)
alteration.alter_column_type(
table.schema,
table.name,
table.columns[column_index].name,
new_type,
engine,
friendly_names=False,
)
return tables.reflect_table_from_oid(table_oid,
engine).columns[column_index]
def drop_column(
engine,
table_oid,
column_index,
):
column_index = int(column_index)
table = tables.reflect_table_from_oid(table_oid, engine)
column = table.columns[column_index]
with engine.begin() as conn:
ctx = MigrationContext.configure(conn)
op = Operations(ctx)
op.drop_column(table.name, column.name, schema=table.schema)
def _sa_table(self):
try:
table = tables.reflect_table_from_oid(
self.oid, self.schema._sa_engine,
)
# We catch these errors, since it lets us decouple the cadence of
# overall DB reflection from the cadence of cache expiration for
# table names. Also, it makes it obvious when the DB layer has
# been altered, as opposed to other reasons for a 404 when
# requesting a table.
except (TypeError, IndexError):
table = tables.create_empty_table("MISSING")
return table
def create_column(engine, table_oid, column_data):
column_type = column_data[TYPE]
column_nullable = column_data.get(NULLABLE, True)
supported_types = alteration.get_supported_alter_column_types(
engine,
friendly_names=False,
)
sa_type = supported_types.get(column_type)
if sa_type is None:
logger.warning("Requested type not supported. falling back to VARCHAR")
sa_type = supported_types["VARCHAR"]
table = tables.reflect_table_from_oid(table_oid, engine)
column = MathesarColumn(
column_data[NAME],
sa_type,
nullable=column_nullable,
)
with engine.begin() as conn:
ctx = MigrationContext.configure(conn)
op = Operations(ctx)
op.add_column(table.name, column, schema=table.schema)
return tables.reflect_table_from_oid(table_oid,
engine).columns[column_data[NAME]]
def test_drop_column_correct_column(engine_with_schema):
engine, schema = engine_with_schema
table_name = "atable"
target_column_name = "thecolumntodrop"
nontarget_column_name = "notthecolumntodrop"
table = Table(
table_name,
MetaData(bind=engine, schema=schema),
Column(target_column_name, Integer),
Column(nontarget_column_name, String),
)
table.create()
table_oid = tables.get_oid_from_table(table_name, schema, engine)
columns.drop_column(engine, table_oid, 0)
altered_table = tables.reflect_table_from_oid(table_oid, engine)
assert len(altered_table.columns) == 1
assert nontarget_column_name in altered_table.columns
assert target_column_name not in altered_table.columns
def test_create_column(engine_with_schema):
engine, schema = engine_with_schema
table_name = "atableone"
target_type = "BOOLEAN"
initial_column_name = "original_column"
new_column_name = "added_column"
table = Table(
table_name,
MetaData(bind=engine, schema=schema),
Column(initial_column_name, Integer),
)
table.create()
table_oid = tables.get_oid_from_table(table_name, schema, engine)
column_data = {"name": new_column_name, "type": target_type}
created_col = columns.create_column(engine, table_oid, column_data)
altered_table = tables.reflect_table_from_oid(table_oid, engine)
assert len(altered_table.columns) == 2
assert created_col.name == new_column_name
assert created_col.type.compile(engine.dialect) == "BOOLEAN"