def visit_update(self, update_stmt, asfrom=False, **kw):
if not self.dialect.supports_update:
raise exc.CompileError(
'ALTER UPDATE is not supported by this server version'
)
render_extra_froms = []
correlate_froms = {update_stmt.table}
self.stack.append(
{
"correlate_froms": correlate_froms,
"asfrom_froms": correlate_froms,
"selectable": update_stmt,
}
)
text = "ALTER TABLE "
table_text = self.update_tables_clause(
update_stmt, update_stmt.table, render_extra_froms, **kw
)
crud_params = crud._setup_crud_params(
self, update_stmt, crud.ISUPDATE, **kw
)
text += table_text
text += " UPDATE "
text += ", ".join(
c[0]._compiler_dispatch(self, include_table=False) +
"=" + c[1]
for c in crud_params
)
if update_stmt._whereclause is not None:
# Do not include table name.
# ClickHouse doesn't expect tablename in where.
t = self.process(update_stmt._whereclause, include_table=False,
**kw)
if t:
text += " WHERE " + t
else:
raise exc.CompileError('WHERE clause is required')
self.stack.pop(-1)
return text
def visit_update(self, update_stmt, asfrom=False, **kw):
extra_froms = update_stmt._extra_froms
is_multitable = bool(extra_froms)
render_extra_froms = []
correlate_froms = {update_stmt.table}
self.stack.append(
{
"correlate_froms": correlate_froms,
"asfrom_froms": correlate_froms,
"selectable": update_stmt,
}
)
text = "ALTER TABLE "
table_text = self.update_tables_clause(
update_stmt, update_stmt.table, render_extra_froms, **kw
)
crud_params = crud._setup_crud_params(
self, update_stmt, crud.ISUPDATE, **kw
)
text += table_text
text += " UPDATE "
include_table = (
is_multitable and self.render_table_with_column_in_update_from
)
text += ", ".join(
c[0]._compiler_dispatch(self, include_table=include_table) +
"=" + c[1]
for c in crud_params
)
if update_stmt._whereclause is not None:
t = self.process(update_stmt._whereclause, **kw)
if t:
text += " WHERE " + t
self.stack.pop(-1)
return text