def range_for_material_objtype(objtype: s_objtypes.ObjectType,
path_id: irast.PathId,
*,
include_overlays: bool = True,
env: context.Environment) -> pgast.BaseRangeVar:
from . import pathctx # XXX: fix cycle
objtype = objtype.material_type(env.schema)
objtype_name = objtype.get_name(env.schema)
table_schema_name, table_name = common.get_backend_name(env.schema,
objtype,
catenate=False)
if objtype_name.module == 'schema':
# Redirect all queries to schema tables to edgedbss
table_schema_name = 'edgedbss'
relation = pgast.Relation(
schemaname=table_schema_name,
name=table_name,
path_id=path_id,
)
rvar = pgast.RangeVar(
relation=relation,
alias=pgast.Alias(aliasname=env.aliases.get(objtype_name.name)))
overlays = env.rel_overlays.get(objtype_name)
if overlays and include_overlays:
set_ops = []
qry = pgast.SelectStmt()
qry.from_clause.append(rvar)
pathctx.put_path_value_rvar(qry, path_id, rvar, env=env)
pathctx.put_path_bond(qry, path_id)
set_ops.append(('union', qry))
for op, cte in overlays:
rvar = pgast.RangeVar(
relation=cte,
alias=pgast.Alias(aliasname=env.aliases.get(hint=cte.name)))
qry = pgast.SelectStmt(from_clause=[rvar], )
pathctx.put_path_value_rvar(qry, path_id, rvar, env=env)
pathctx.put_path_bond(qry, path_id)
if op == 'replace':
op = 'union'
set_ops = []
set_ops.append((op, qry))
rvar = range_from_queryset(set_ops, objtype, env=env)
return rvar
def range_from_queryset(
set_ops: typing.Sequence[typing.Tuple[str, pgast.BaseRelation]],
scls: s_obj.Object, *,
env: context.Environment) -> pgast.BaseRangeVar:
if len(set_ops) > 1:
# More than one class table, generate a UNION/EXCEPT clause.
qry = pgast.SelectStmt(
all=True,
larg=set_ops[0][1]
)
for op, rarg in set_ops[1:]:
qry.op, qry.rarg = op, rarg
qry = pgast.SelectStmt(
all=True,
larg=qry
)
qry = qry.larg
rvar = pgast.RangeSubselect(
subquery=qry,
alias=pgast.Alias(
aliasname=env.aliases.get(scls.shortname.name)
)
)
else:
# Just one class table, so return it directly
rvar = set_ops[0][1].from_clause[0]
return rvar
def top_output_as_value(stmt: pgast.Query, *,
env: context.Environment) -> pgast.Query:
"""Finalize output serialization on the top level."""
if env.output_format == context.OutputFormat.JSON:
# For JSON we just want to aggregate the whole thing
# into a JSON array.
subrvar = pgast.RangeSubselect(
subquery=stmt,
alias=pgast.Alias(aliasname=env.aliases.get('aggw')))
stmt_res = stmt.target_list[0]
if stmt_res.name is None:
stmt_res.name = env.aliases.get('v')
new_val = pgast.FuncCall(name=('json_agg', ),
args=[pgast.ColumnRef(name=[stmt_res.name])])
# XXX: nullability introspection is not reliable,
# remove `True or` once it is.
if True or stmt_res.val.nullable:
new_val = pgast.CoalesceExpr(
args=[new_val, pgast.Constant(val='[]')])
result = pgast.SelectStmt(target_list=[pgast.ResTarget(val=new_val)],
from_clause=[subrvar])
result.ctes = stmt.ctes
stmt.ctes = []
return result
else:
return stmt
def cte_for_query(
rel: pgast.Query, *,
env: context.Environment) -> pgast.CommonTableExpr:
return pgast.CommonTableExpr(
query=rel,
alias=pgast.Alias(
aliasname=env.aliases.get(rel.name)
)
)
def array_as_json_object(expr, *, stype, env):
if stype.element_type.is_tuple():
coldeflist = []
json_args = []
is_named = stype.element_type.named
for n, st in stype.element_type.iter_subtypes():
colname = env.aliases.get(str(n))
if is_named:
json_args.append(pgast.StringConstant(val=n))
val = pgast.ColumnRef(name=[colname])
if st.is_collection():
val = coll_as_json_object(val, stype=st, env=env)
json_args.append(val)
coldeflist.append(
pgast.ColumnDef(
name=colname,
typename=pgast.TypeName(
name=pgtypes.pg_type_from_object(env.schema, st))))
if is_named:
json_func = 'jsonb_build_object'
else:
json_func = 'jsonb_build_array'
return pgast.SelectStmt(target_list=[
pgast.ResTarget(
val=pgast.FuncCall(name=('jsonb_agg', ),
args=[
pgast.FuncCall(
name=(json_func, ),
args=json_args,
)
]),
ser_safe=True,
)
],
from_clause=[
pgast.RangeFunction(
alias=pgast.Alias(
aliasname=env.aliases.get('q'), ),
coldeflist=coldeflist,
functions=[
pgast.FuncCall(
name=('unnest', ),
args=[expr],
)
])
])
else:
return pgast.FuncCall(name=('to_jsonb', ),
args=[expr],
null_safe=True,
ser_safe=True)
def process_linkprop_update(ir_stmt: irast.MutatingStmt, ir_expr: irast.Base,
wrapper: pgast.Query,
dml_cte: pgast.CommonTableExpr, *,
ctx: context.CompilerContextLevel) -> None:
"""Perform link property updates to a link relation.
:param ir_stmt:
IR of the statement.
:param ir_expr:
IR of the UPDATE body element.
:param wrapper:
Top-level SQL query.
:param dml_cte:
CTE representing the SQL UPDATE to the main relation of the Object.
"""
toplevel = ctx.toplevel_stmt
rptr = ir_expr.rptr
ptrcls = rptr.ptrcls
target_tab = dbobj.range_for_ptrcls(ptrcls,
'>',
include_overlays=False,
env=ctx.env)
dml_cte_rvar = pgast.RangeVar(
relation=dml_cte,
alias=pgast.Alias(aliasname=ctx.env.aliases.get('m')))
cond = astutils.new_binop(
pathctx.get_rvar_path_identity_var(dml_cte_rvar,
ir_stmt.subject.path_id,
env=ctx.env),
dbobj.get_column(target_tab, 'source', nullable=False),
op='=',
)
targets = []
for prop_el in ir_expr.shape:
ptrname = prop_el.rptr.ptrcls.get_shortname(ctx.env.schema)
with ctx.new() as input_rel_ctx:
input_rel_ctx.expr_exposed = False
input_rel = dispatch.compile(prop_el.expr, ctx=input_rel_ctx)
targets.append(pgast.UpdateTarget(name=ptrname.name,
val=input_rel))
updstmt = pgast.UpdateStmt(relation=target_tab,
where_clause=cond,
targets=targets,
from_clause=[dml_cte_rvar])
updcte = pgast.CommonTableExpr(
query=updstmt,
name=ctx.env.aliases.get(ptrcls.get_shortname(ctx.env.schema).name))
toplevel.ctes.append(updcte)
def rvar_for_rel(
rel: pgast.BaseRelation, *,
lateral: bool=False, colnames: typing.List[str]=[],
env: context.Environment) -> pgast.BaseRangeVar:
if isinstance(rel, pgast.Query):
alias = env.aliases.get(rel.name or 'q')
rvar = pgast.RangeSubselect(
subquery=rel,
alias=pgast.Alias(aliasname=alias, colnames=colnames),
lateral=lateral,
)
else:
alias = env.aliases.get(rel.name)
rvar = pgast.RangeVar(
relation=rel,
alias=pgast.Alias(aliasname=alias, colnames=colnames)
)
return rvar
def table_from_ptrcls(ptrcls: s_links.Link, *,
env: context.Environment) -> pgast.RangeVar:
"""Return a Table corresponding to a given Link."""
table_schema_name, table_name = common.get_table_name(ptrcls,
catenate=False)
pname = ptrcls.shortname
if pname.module == 'schema':
# Redirect all queries to schema tables to edgedbss
table_schema_name = 'edgedbss'
relation = pgast.Relation(schemaname=table_schema_name, name=table_name)
rvar = pgast.RangeVar(
relation=relation,
alias=pgast.Alias(aliasname=env.aliases.get(pname.name)))
return rvar
def cast(node: pgast.Base,
*,
source_type: s_obj.Object,
target_type: s_obj.Object,
force: bool = False,
env: context.Environment) -> pgast.Base:
if source_type.name == target_type.name and not force:
return node
schema = env.schema
real_t = schema.get('std::anyreal')
int_t = schema.get('std::anyint')
json_t = schema.get('std::json')
str_t = schema.get('std::str')
datetime_t = schema.get('std::datetime')
bool_t = schema.get('std::bool')
if isinstance(target_type, s_types.Collection):
if target_type.schema_name == 'array':
if source_type.issubclass(json_t):
# If we are casting a jsonb array to array, we do the
# following transformation:
# EdgeQL: <array<T>>MAP_VALUE
# SQL:
# SELECT array_agg(j::T)
# FROM jsonb_array_elements(MAP_VALUE) AS j
inner_cast = cast(pgast.ColumnRef(name=['j']),
source_type=source_type,
target_type=target_type.element_type,
env=env)
return pgast.SelectStmt(
target_list=[
pgast.ResTarget(val=pgast.FuncCall(
name=('array_agg', ), args=[inner_cast]))
],
from_clause=[
pgast.RangeFunction(functions=[
pgast.FuncCall(name=('jsonb_array_elements', ),
args=[node])
],
alias=pgast.Alias(aliasname='j'))
])
else:
# EdgeQL: <array<int64>>['1', '2']
# to SQL: ARRAY['1', '2']::int[]
elem_pgtype = pg_types.pg_type_from_object(
schema, target_type.element_type, topbase=True)
return pgast.TypeCast(arg=node,
type_name=pgast.TypeName(
name=elem_pgtype, array_bounds=[-1]))
else:
# `target_type` is not a collection.
if (source_type.issubclass(datetime_t)
and target_type.issubclass(str_t)):
# Normalize datetime to text conversion to have the same
# format as one would get by serializing to JSON.
#
# EdgeQL: <text><datetime>'2010-10-10';
# To SQL: trim(to_json('2010-01-01'::timestamptz)::text, '"')
return pgast.FuncCall(
name=('trim', ),
args=[
pgast.TypeCast(arg=pgast.FuncCall(name=('to_json', ),
args=[node]),
type_name=pgast.TypeName(name=('text', ))),
pgast.Constant(val='"')
])
elif source_type.issubclass(bool_t) and target_type.issubclass(int_t):
# PostgreSQL 9.6 doesn't allow to cast 'boolean' to any integer
# other than int32:
# SELECT 'true'::boolean::bigint;
# ERROR: cannot cast type boolean to bigint
# So we transform EdgeQL: <int64>BOOL
# to SQL: BOOL::int::<targetint>
return pgast.TypeCast(
arg=pgast.TypeCast(arg=node,
type_name=pgast.TypeName(name=('int', ))),
type_name=pgast.TypeName(
name=pg_types.pg_type_from_scalar(schema, target_type)))
elif source_type.issubclass(int_t) and target_type.issubclass(bool_t):
# PostgreSQL 9.6 doesn't allow to cast any integer other
# than int32 to 'boolean':
# SELECT 1::bigint::boolean;
# ERROR: cannot cast type bigint to boolea
# So we transform EdgeQL: <boolean>INT
# to SQL: (INT != 0)
return astutils.new_binop(node,
pgast.Constant(val=0),
op=ast.ops.NE)
elif source_type.issubclass(json_t):
if (target_type.issubclass(real_t)
or target_type.issubclass(bool_t)):
# Simply cast to text and the to the target type.
return cast(cast(node,
source_type=source_type,
target_type=str_t,
env=env),
source_type=str_t,
target_type=target_type,
env=env)
elif target_type.issubclass(str_t):
# It's not possible to cast jsonb string to text directly,
# so we do a trick:
# EdgeQL: <str>JSONB_VAL
# SQL: array_to_json(ARRAY[JSONB_VAL])->>0
return astutils.new_binop(pgast.FuncCall(
name=('array_to_json', ),
args=[pgast.ArrayExpr(elements=[node])]),
pgast.Constant(val=0),
op='->>')
elif target_type.issubclass(json_t):
return pgast.TypeCast(
arg=node, type_name=pgast.TypeName(name=('jsonb', )))
else:
const_type = pg_types.pg_type_from_object(schema,
target_type,
topbase=True)
return pgast.TypeCast(arg=node,
type_name=pgast.TypeName(name=const_type))
raise RuntimeError(
f'could not cast {source_type.name} to {target_type.name}')
def process_link_values(
ir_stmt, ir_expr, target_tab, tab_cols, col_data,
dml_rvar, sources, props_only, target_is_scalar, iterator_cte, *,
ctx=context.CompilerContext) -> \
typing.Tuple[pgast.CommonTableExpr, typing.List[str]]:
"""Unpack data from an update expression into a series of selects.
:param ir_expr:
IR of the INSERT/UPDATE body element.
:param target_tab:
The link table being updated.
:param tab_cols:
A sequence of columns in the table being updated.
:param col_data:
Expressions used to populate well-known columns of the link
table such as std::source and std::__type__.
:param sources:
A list of relations which must be joined into the data query
to resolve expressions in *col_data*.
:param props_only:
Whether this link update only touches link properties.
:param target_is_scalar:
Whether the link target is an ScalarType.
:param iterator_cte:
CTE representing the iterator range in the FOR clause of the
EdgeQL DML statement.
"""
with ctx.newscope() as newscope, newscope.newrel() as subrelctx:
row_query = subrelctx.rel
relctx.include_rvar(row_query,
dml_rvar,
path_id=ir_stmt.subject.path_id,
ctx=subrelctx)
subrelctx.path_scope[ir_stmt.subject.path_id] = row_query
if iterator_cte is not None:
iterator_rvar = dbobj.rvar_for_rel(iterator_cte,
lateral=True,
env=subrelctx.env)
relctx.include_rvar(row_query,
iterator_rvar,
path_id=iterator_cte.query.path_id,
ctx=subrelctx)
with subrelctx.newscope() as sctx, sctx.subrel() as input_rel_ctx:
input_rel = input_rel_ctx.rel
if iterator_cte is not None:
input_rel_ctx.path_scope[iterator_cte.query.path_id] = \
row_query
input_rel_ctx.expr_exposed = False
input_rel_ctx.shape_format = context.ShapeFormat.FLAT
input_rel_ctx.volatility_ref = pathctx.get_path_identity_var(
row_query, ir_stmt.subject.path_id, env=input_rel_ctx.env)
dispatch.compile(ir_expr, ctx=input_rel_ctx)
input_stmt = input_rel
input_rvar = pgast.RangeSubselect(
subquery=input_rel,
lateral=True,
alias=pgast.Alias(aliasname=ctx.env.aliases.get('val')))
source_data = {}
if input_stmt.op is not None:
# UNION
input_stmt = input_stmt.rarg
path_id = ir_expr.path_id
output = pathctx.get_path_value_output(input_stmt, path_id, env=ctx.env)
if isinstance(output, pgast.TupleVar):
for element in output.elements:
name = element.path_id.rptr_name()
if name is None:
name = element.path_id[-1].name
colname = common.edgedb_name_to_pg_name(name)
source_data.setdefault(colname,
dbobj.get_column(input_rvar, element.name))
else:
if target_is_scalar:
target_ref = pathctx.get_rvar_path_value_var(input_rvar,
path_id,
env=ctx.env)
else:
target_ref = pathctx.get_rvar_path_identity_var(input_rvar,
path_id,
env=ctx.env)
source_data['std::target'] = target_ref
if not target_is_scalar and 'std::target' not in source_data:
target_ref = pathctx.get_rvar_path_identity_var(input_rvar,
path_id,
env=ctx.env)
source_data['std::target'] = target_ref
specified_cols = []
for col in tab_cols:
expr = col_data.get(col)
if expr is None:
expr = source_data.get(col)
if expr is not None:
row_query.target_list.append(pgast.ResTarget(val=expr, name=col))
specified_cols.append(col)
row_query.from_clause += list(sources) + [input_rvar]
link_rows = pgast.CommonTableExpr(query=row_query,
name=ctx.env.aliases.get(hint='r'))
return link_rows, specified_cols
def process_link_update(
ir_stmt: irast.MutatingStmt, ir_expr: irast.Base, props_only: bool,
wrapper: pgast.Query, dml_cte: pgast.CommonTableExpr,
iterator_cte: pgast.CommonTableExpr, *,
ctx: context.CompilerContextLevel) -> typing.Optional[pgast.Query]:
"""Perform updates to a link relation as part of a DML statement.
:param ir_stmt:
IR of the statement.
:param ir_expr:
IR of the INSERT/UPDATE body element.
:param props_only:
Whether this link update only touches link properties.
:param wrapper:
Top-level SQL query.
:param dml_cte:
CTE representing the SQL INSERT or UPDATE to the main
relation of the Object.
:param iterator_cte:
CTE representing the iterator range in the FOR clause of the
EdgeQL DML statement.
"""
toplevel = ctx.toplevel_stmt
edgedb_ptr_tab = pgast.RangeVar(
relation=pgast.Relation(schemaname='edgedb', name='pointer'),
alias=pgast.Alias(aliasname=ctx.env.aliases.get(hint='ptr')))
ltab_alias = edgedb_ptr_tab.alias.aliasname
rptr = ir_expr.rptr
ptrcls = rptr.ptrcls
target_is_scalar = isinstance(ptrcls.target, s_scalars.ScalarType)
path_id = rptr.source.path_id.extend(ptrcls, rptr.direction,
rptr.target.scls)
# The links in the dml class shape have been derived,
# but we must use the correct specialized link class for the
# base material type.
mptrcls = ptrcls.material_type()
# Lookup link class id by link name.
lname_to_id = pgast.CommonTableExpr(query=pgast.SelectStmt(
from_clause=[edgedb_ptr_tab],
target_list=[
pgast.ResTarget(val=pgast.ColumnRef(name=[ltab_alias, 'id']))
],
where_clause=astutils.new_binop(
lexpr=pgast.ColumnRef(name=[ltab_alias, 'name']),
rexpr=pgast.Constant(val=mptrcls.name),
op=ast.ops.EQ)),
name=ctx.env.aliases.get(hint='lid'))
lname_to_id_rvar = pgast.RangeVar(relation=lname_to_id)
toplevel.ctes.append(lname_to_id)
target_rvar = dbobj.range_for_ptrcls(mptrcls,
'>',
include_overlays=False,
env=ctx.env)
target_alias = target_rvar.alias.aliasname
target_tab_name = (target_rvar.relation.schemaname,
target_rvar.relation.name)
tab_cols = dbobj.cols_for_pointer(mptrcls, env=ctx.env)
dml_cte_rvar = pgast.RangeVar(
relation=dml_cte,
alias=pgast.Alias(aliasname=ctx.env.aliases.get('m')))
col_data = {
'ptr_item_id':
pgast.ColumnRef(name=[lname_to_id.name, 'id']),
'std::source':
pathctx.get_rvar_path_identity_var(dml_cte_rvar,
ir_stmt.subject.path_id,
env=ctx.env)
}
# Drop all previous link records for this source.
delcte = pgast.CommonTableExpr(query=pgast.DeleteStmt(
relation=target_rvar,
where_clause=astutils.new_binop(
lexpr=col_data['std::source'],
op=ast.ops.EQ,
rexpr=pgast.ColumnRef(name=[target_alias, 'std::source'])),
using_clause=[dml_cte_rvar],
returning_list=[
pgast.ResTarget(val=pgast.ColumnRef(
name=[target_alias, pgast.Star()]))
]),
name=ctx.env.aliases.get(hint='d'))
pathctx.put_path_value_rvar(delcte.query,
path_id.ptr_path(),
target_rvar,
env=ctx.env)
# Record the effect of this removal in the relation overlay
# context to ensure that the RETURNING clause potentially
# referencing this link yields the expected results.
overlays = ctx.env.rel_overlays[ptrcls.shortname]
overlays.append(('except', delcte))
toplevel.ctes.append(delcte)
# Turn the IR of the expression on the right side of :=
# into a subquery returning records for the link table.
data_cte, specified_cols = process_link_values(ir_stmt,
ir_expr,
target_tab_name,
tab_cols,
col_data,
dml_cte_rvar,
[lname_to_id_rvar],
props_only,
target_is_scalar,
iterator_cte,
ctx=ctx)
toplevel.ctes.append(data_cte)
data_select = pgast.SelectStmt(
target_list=[
pgast.ResTarget(val=pgast.ColumnRef(
name=[data_cte.name, pgast.Star()]))
],
from_clause=[pgast.RangeVar(relation=data_cte)])
# Inserting rows into the link table may produce cardinality
# constraint violations, since the INSERT into the link table
# is executed in the snapshot where the above DELETE from
# the link table is not visible. Hence, we need to use
# the ON CONFLICT clause to resolve this.
conflict_cols = ['std::source', 'std::target', 'ptr_item_id']
conflict_inference = []
conflict_exc_row = []
for col in conflict_cols:
conflict_inference.append(pgast.ColumnRef(name=[col]))
conflict_exc_row.append(pgast.ColumnRef(name=['excluded', col]))
conflict_data = pgast.SelectStmt(
target_list=[
pgast.ResTarget(val=pgast.ColumnRef(
name=[data_cte.name, pgast.Star()]))
],
from_clause=[pgast.RangeVar(relation=data_cte)],
where_clause=astutils.new_binop(
lexpr=pgast.ImplicitRowExpr(args=conflict_inference),
rexpr=pgast.ImplicitRowExpr(args=conflict_exc_row),
op='='))
cols = [pgast.ColumnRef(name=[col]) for col in specified_cols]
updcte = pgast.CommonTableExpr(
name=ctx.env.aliases.get(hint='i'),
query=pgast.InsertStmt(
relation=target_rvar,
select_stmt=data_select,
cols=cols,
on_conflict=pgast.OnConflictClause(
action='update',
infer=pgast.InferClause(index_elems=conflict_inference),
target_list=[
pgast.MultiAssignRef(columns=cols, source=conflict_data)
]),
returning_list=[
pgast.ResTarget(val=pgast.ColumnRef(name=[pgast.Star()]))
]))
pathctx.put_path_value_rvar(updcte.query,
path_id.ptr_path(),
target_rvar,
env=ctx.env)
# Record the effect of this insertion in the relation overlay
# context to ensure that the RETURNING clause potentially
# referencing this link yields the expected results.
overlays = ctx.env.rel_overlays[ptrcls.shortname]
overlays.append(('union', updcte))
toplevel.ctes.append(updcte)
return data_cte
def init_dml_stmt(
ir_stmt: irast.MutatingStmt, dml_stmt: pgast.DML, *,
ctx: context.CompilerContextLevel,
parent_ctx: context.CompilerContextLevel) \
-> typing.Tuple[pgast.Query, pgast.CommonTableExpr,
pgast.CommonTableExpr]:
"""Prepare the common structure of the query representing a DML stmt.
:param ir_stmt:
IR of the statement.
:param dml_stmt:
SQL DML node instance.
:return:
A (*wrapper*, *dml_cte*, *range_cte*) tuple, where *wrapper* the
the wrapping SQL statement, *dml_cte* is the CTE representing the
SQL DML operation in the main relation of the Object, and
*range_cte* is the CTE for the subset affected by the statement.
*range_cte* is None for INSERT statmenets.
"""
wrapper = ctx.rel
clauses.init_stmt(ir_stmt, ctx, parent_ctx)
target_ir_set = ir_stmt.subject
dml_stmt.relation = dbobj.range_for_set(ir_stmt.subject,
include_overlays=False,
env=ctx.env)
pathctx.put_path_value_rvar(dml_stmt,
target_ir_set.path_id,
dml_stmt.relation,
env=ctx.env)
pathctx.put_path_source_rvar(dml_stmt,
target_ir_set.path_id,
dml_stmt.relation,
env=ctx.env)
dml_stmt.path_scope.add(target_ir_set.path_id)
dml_cte = pgast.CommonTableExpr(query=dml_stmt,
name=ctx.env.aliases.get(hint='m'))
if isinstance(ir_stmt, (irast.UpdateStmt, irast.DeleteStmt)):
# UPDATE and DELETE operate over a range, so generate
# the corresponding CTE and connect it to the DML query.
range_cte = get_dml_range(ir_stmt, dml_stmt, ctx=ctx)
range_rvar = pgast.RangeVar(
relation=range_cte,
alias=pgast.Alias(aliasname=ctx.env.aliases.get(hint='range')))
relctx.pull_path_namespace(target=dml_stmt, source=range_rvar, ctx=ctx)
# Auxillary relations are always joined via the WHERE
# clause due to the structure of the UPDATE/DELETE SQL statments.
id_col = common.edgedb_name_to_pg_name('std::id')
dml_stmt.where_clause = astutils.new_binop(
lexpr=pgast.ColumnRef(
name=[dml_stmt.relation.alias.aliasname, id_col]),
op=ast.ops.EQ,
rexpr=pathctx.get_rvar_path_identity_var(range_rvar,
target_ir_set.path_id,
env=ctx.env))
# UPDATE has "FROM", while DELETE has "USING".
if hasattr(dml_stmt, 'from_clause'):
dml_stmt.from_clause.append(range_rvar)
else:
dml_stmt.using_clause.append(range_rvar)
else:
range_cte = None
# Due to the fact that DML statements are structured
# as a flat list of CTEs instead of nested range vars,
# the top level path scope must be empty. The necessary
# range vars will be injected explicitly in all rels that
# need them.
ctx.path_scope.clear()
pathctx.put_path_value_rvar(dml_stmt,
ir_stmt.subject.path_id,
dml_stmt.relation,
env=ctx.env)
pathctx.put_path_source_rvar(dml_stmt,
ir_stmt.subject.path_id,
dml_stmt.relation,
env=ctx.env)
dml_rvar = pgast.RangeVar(
relation=dml_cte,
alias=pgast.Alias(aliasname=parent_ctx.env.aliases.get('d')))
relctx.include_rvar(wrapper, dml_rvar, ir_stmt.subject.path_id, ctx=ctx)
pathctx.put_path_bond(wrapper, ir_stmt.subject.path_id)
return wrapper, dml_cte, dml_rvar, range_cte
def range_for_ptrcls(
ptrcls: s_links.Link, direction: s_pointers.PointerDirection, *,
include_overlays: bool=True,
env: context.Environment) -> pgast.BaseRangeVar:
""""Return a Range subclass corresponding to a given ptr step.
If `ptrcls` is a generic link, then a simple RangeVar is returned,
otherwise the return value may potentially be a UNION of all tables
corresponding to a set of specialized links computed from the given
`ptrcls` taking source inheritance into account.
"""
linkname = ptrcls.shortname
endpoint = ptrcls.source
tgt_col = pgtypes.get_pointer_storage_info(
ptrcls, resolve_type=False, link_bias=True).column_name
cols = [
'std::source',
tgt_col
]
set_ops = []
ptrclses = set()
for source in {endpoint} | set(endpoint.descendants(env.schema)):
# Sift through the descendants to see who has this link
try:
src_ptrcls = source.pointers[linkname].material_type()
except KeyError:
# This source has no such link, skip it
continue
else:
if src_ptrcls in ptrclses:
# Seen this link already
continue
ptrclses.add(src_ptrcls)
table = table_from_ptrcls(src_ptrcls, env=env)
qry = pgast.SelectStmt()
qry.from_clause.append(table)
qry.rptr_rvar = table
# Make sure all property references are pulled up properly
for colname in cols:
selexpr = pgast.ColumnRef(
name=[table.alias.aliasname, colname])
qry.target_list.append(
pgast.ResTarget(val=selexpr, name=colname))
set_ops.append(('union', qry))
overlays = env.rel_overlays.get(src_ptrcls.shortname)
if overlays and include_overlays:
for op, cte in overlays:
rvar = pgast.RangeVar(
relation=cte,
alias=pgast.Alias(
aliasname=env.aliases.get(cte.name)
)
)
qry = pgast.SelectStmt(
target_list=[
pgast.ResTarget(
val=pgast.ColumnRef(
name=[col]
)
)
for col in cols
],
from_clause=[rvar],
)
set_ops.append((op, qry))
rvar = range_from_queryset(set_ops, ptrcls, env=env)
return rvar
