liquibase-core/src/main/java/liquibase/change/core/DropAllForeignKeyConstraintsChange.java
private List<DropForeignKeyConstraintChange> generateChildren(Database database) {
        // Make a new list
        List<DropForeignKeyConstraintChange> childDropChanges = new ArrayList<>();

        try {
            SnapshotControl control = new SnapshotControl(database);
            control.getTypesToInclude().add(ForeignKey.class);
            CatalogAndSchema catalogAndSchema =
                    new CatalogAndSchema(getBaseTableCatalogName(), getBaseTableSchemaName());
            catalogAndSchema = catalogAndSchema.standardize(database);
            Table target = SnapshotGeneratorFactory.getInstance().createSnapshot(
                    new Table(catalogAndSchema.getCatalogName(), catalogAndSchema.getSchemaName(),
                            database.correctObjectName(getBaseTableName(), Table.class))
                    , database);

            List<ForeignKey> results = ((target == null) ? null : target.getOutgoingForeignKeys());
            Set<String> handledConstraints = new HashSet<>();

            if ((results != null) && (!results.isEmpty())) {
                for (ForeignKey fk : results) {
                    Table baseTable = fk.getForeignKeyTable();
                    String constraintName = fk.getName();
                    if (DatabaseObjectComparatorFactory.getInstance().isSameObject(
                            baseTable,
                            target,
                            null,
                            database
                    )) {
                        if( !handledConstraints.contains(constraintName)) {
                            DropForeignKeyConstraintChange dropForeignKeyConstraintChange =
                                    new DropForeignKeyConstraintChange();

                            dropForeignKeyConstraintChange.setBaseTableSchemaName(getBaseTableSchemaName());
                            dropForeignKeyConstraintChange.setBaseTableName(baseTableName);
                            dropForeignKeyConstraintChange.setConstraintName(constraintName);

                            childDropChanges.add(dropForeignKeyConstraintChange);
                            handledConstraints.add(constraintName);
                        }
                    } else {
                        throw new UnexpectedLiquibaseException(
                                "Expected to return only foreign keys for base table name: " +
                                        getBaseTableName() + " and got results for table: " + baseTableName);
                    }
                }
            }

            return childDropChanges;

        } catch (DatabaseException | InvalidExampleException e) {
            throw new UnexpectedLiquibaseException("Failed to find foreign keys for table: " + getBaseTableName(), e);
        }
    }
private List<DropForeignKeyConstraintChange> generateChildren(Database database) {
        // Make a new list
        List<DropForeignKeyConstraintChange> childDropChanges = new ArrayList<>();

        try {
            SnapshotControl control = new SnapshotControl(database);
            control.getTypesToInclude().add(ForeignKey.class);
            CatalogAndSchema catalogAndSchema =
                    new CatalogAndSchema(getBaseTableCatalogName(), getBaseTableSchemaName());
            catalogAndSchema = catalogAndSchema.standardize(database);
            Table target = SnapshotGeneratorFactory.getInstance().createSnapshot(
                    new Table(catalogAndSchema.getCatalogName(), catalogAndSchema.getSchemaName(),
                            database.correctObjectName(getBaseTableName(), Table.class))
                    , database);

            List<ForeignKey> results = ((target == null) ? null : target.getOutgoingForeignKeys());
            Set<String> handledConstraints = new HashSet<>();

            if ((results != null) && (!results.isEmpty())) {
                for (ForeignKey fk : results) {
                    Table baseTable = fk.getForeignKeyTable();
                    String constraintName = fk.getName();
                    if (DatabaseObjectComparatorFactory.getInstance().isSameObject(
                            baseTable,
                            target,
                            null,
                            database
                    )) {
                        if( !handledConstraints.contains(constraintName)) {
                            DropForeignKeyConstraintChange dropForeignKeyConstraintChange =
                                    new DropForeignKeyConstraintChange();

                            dropForeignKeyConstraintChange.setBaseTableSchemaName(getBaseTableSchemaName());
                            dropForeignKeyConstraintChange.setBaseTableName(baseTableName);
                            dropForeignKeyConstraintChange.setConstraintName(constraintName);

                            childDropChanges.add(dropForeignKeyConstraintChange);
                            handledConstraints.add(constraintName);
                        }
                    } else {
                        throw new UnexpectedLiquibaseException(
                                "Expected to return only foreign keys for base table name: " +
                                        getBaseTableName() + " and got results for table: " + baseTableName);
                    }
                }
            }

            return childDropChanges;

        } catch (DatabaseException | InvalidExampleException e) {
            throw new UnexpectedLiquibaseException("Failed to find foreign keys for table: " + getBaseTableName(), e);
        }
    }
Iterates through all the FOREIGN KEYs of the target table and outputs a list of DropForeignKeyConstraintChanges
for a given database type.

@param database the database type for which subchanges need to be generated
@return the list of generated DropForeignKeyConstraintChanges