github.com/dolthub/go-mysql-server@v0.18.0/memory/foreign_key_collection.go (about)

     1  // Copyright 2022 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package memory
    16  
    17  import (
    18  	"strings"
    19  
    20  	"github.com/dolthub/go-mysql-server/sql"
    21  )
    22  
    23  // ForeignKeyCollection is a shareable container for a collection of foreign keys.
    24  type ForeignKeyCollection struct {
    25  	fks []sql.ForeignKeyConstraint
    26  }
    27  
    28  // newForeignKeyCollection returns a new ForeignKeyCollection.
    29  func newForeignKeyCollection() *ForeignKeyCollection {
    30  	return &ForeignKeyCollection{}
    31  }
    32  
    33  // AddFK adds the given foreign key to the internal slice.
    34  func (fkc *ForeignKeyCollection) AddFK(fk sql.ForeignKeyConstraint) {
    35  	if fkc == nil {
    36  		return
    37  	}
    38  	fkc.fks = append(fkc.fks, fk)
    39  }
    40  
    41  // DropFK removes the given foreign key from the internal slice. Returns true if the foreign key was found.
    42  func (fkc *ForeignKeyCollection) DropFK(fkName string) bool {
    43  	if fkc == nil {
    44  		return false
    45  	}
    46  	fkLowerName := strings.ToLower(fkName)
    47  	for i, existingFk := range fkc.fks {
    48  		if fkLowerName == strings.ToLower(existingFk.Name) {
    49  			fkc.fks = append(fkc.fks[:i], fkc.fks[i+1:]...)
    50  			return true
    51  		}
    52  	}
    53  	return false
    54  }
    55  
    56  // SetResolved sets the given foreign key as being resolved.
    57  func (fkc *ForeignKeyCollection) SetResolved(fkName string) bool {
    58  	if fkc == nil {
    59  		return false
    60  	}
    61  	fkLowerName := strings.ToLower(fkName)
    62  	for i, existingFk := range fkc.fks {
    63  		if fkLowerName == strings.ToLower(existingFk.Name) {
    64  			fkc.fks[i].IsResolved = true
    65  			return true
    66  		}
    67  	}
    68  	return false
    69  }
    70  
    71  // Keys returns all of the foreign keys.
    72  func (fkc *ForeignKeyCollection) Keys() []sql.ForeignKeyConstraint {
    73  	if fkc == nil {
    74  		return nil
    75  	}
    76  	return fkc.fks
    77  }