github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/sql/row/fk_existence_check.go (about)

     1  // Copyright 2019 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  package row
    12  
    13  import (
    14  	"context"
    15  
    16  	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgcode"
    17  	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgerror"
    18  	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
    19  	"github.com/cockroachdb/cockroach/pkg/sql/sqlbase"
    20  	"github.com/cockroachdb/cockroach/pkg/util/errorutil/unimplemented"
    21  	"github.com/cockroachdb/errors"
    22  )
    23  
    24  // queueFkExistenceChecksForRow initiates FK existence checks for a
    25  // given mutated row.
    26  func queueFkExistenceChecksForRow(
    27  	ctx context.Context,
    28  	checkRunner *fkExistenceBatchChecker,
    29  	mutatedIdxHelpers []fkExistenceCheckBaseHelper,
    30  	mutatedRow tree.Datums,
    31  	traceKV bool,
    32  ) error {
    33  outer:
    34  	for i, fk := range mutatedIdxHelpers {
    35  		// See https://github.com/cockroachdb/cockroach/issues/20305 or
    36  		// https://www.postgresql.org/docs/11/sql-createtable.html for details on the
    37  		// different composite foreign key matching methods.
    38  		//
    39  		// TODO(knz): it is inefficient to do this dynamic dispatch based on
    40  		// the match type and column layout again for every row. Consider
    41  		// hoisting some of these checks to once per logical plan.
    42  		switch fk.ref.Match {
    43  		case sqlbase.ForeignKeyReference_SIMPLE:
    44  			for _, colID := range fk.searchIdx.ColumnIDs[:fk.prefixLen] {
    45  				found, ok := fk.ids[colID]
    46  				if !ok {
    47  					return errors.AssertionFailedf("fk ids (%v) missing column id %d", fk.ids, colID)
    48  				}
    49  				if mutatedRow[found] == tree.DNull {
    50  					continue outer
    51  				}
    52  			}
    53  			if err := checkRunner.addCheck(ctx, mutatedRow, &mutatedIdxHelpers[i], traceKV); err != nil {
    54  				return err
    55  			}
    56  
    57  		case sqlbase.ForeignKeyReference_FULL:
    58  			var nulls, notNulls bool
    59  			for _, colID := range fk.searchIdx.ColumnIDs[:fk.prefixLen] {
    60  				found, ok := fk.ids[colID]
    61  				if !ok {
    62  					return errors.AssertionFailedf("fk ids (%v) missing column id %d", fk.ids, colID)
    63  				}
    64  				if mutatedRow[found] == tree.DNull {
    65  					nulls = true
    66  				} else {
    67  					notNulls = true
    68  				}
    69  			}
    70  			if nulls && notNulls {
    71  				// TODO(bram): expand this error to show more details.
    72  				return pgerror.Newf(pgcode.ForeignKeyViolation,
    73  					"foreign key violation: MATCH FULL does not allow mixing of null and nonnull values %s for %s",
    74  					mutatedRow, fk.ref.Name,
    75  				)
    76  			}
    77  			// Never check references for MATCH FULL that are all nulls.
    78  			if nulls {
    79  				continue
    80  			}
    81  			if err := checkRunner.addCheck(ctx, mutatedRow, &mutatedIdxHelpers[i], traceKV); err != nil {
    82  				return err
    83  			}
    84  
    85  		case sqlbase.ForeignKeyReference_PARTIAL:
    86  			return unimplemented.NewWithIssue(20305, "MATCH PARTIAL not supported")
    87  
    88  		default:
    89  			return errors.AssertionFailedf("unknown composite key match type: %v", fk.ref.Match)
    90  		}
    91  	}
    92  	return nil
    93  }