def compile_InsertStmt(stmt: irast.InsertStmt, *,
ctx: context.CompilerContextLevel) -> pgast.Query:
parent_ctx = ctx
with parent_ctx.substmt() as ctx:
# Common DML bootstrap.
wrapper, insert_cte, insert_rvar, _ = dml.init_dml_stmt(
stmt, pgast.InsertStmt(), parent_ctx=parent_ctx, ctx=ctx)
# Process INSERT body.
dml.process_insert_body(stmt,
wrapper,
insert_cte,
insert_rvar,
ctx=ctx)
# Wrap up.
return dml.fini_dml_stmt(stmt,
wrapper,
insert_cte,
insert_rvar,
parent_ctx=parent_ctx,
ctx=ctx)
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