Function generateUpdateRestore

backend/plugin/parser/mysql/restore.go:105–149

(ctx context.Context, rCtx base.RestoreContext, stmt *ast.UpdateStmt, originalDatabase, originalTable, backupDatabase, backupTable string, normalColumns []string)

}

func generateUpdateRestore(ctx context.Context, rCtx base.RestoreContext, stmt *ast.UpdateStmt, originalDatabase, originalTable, backupDatabase, backupTable string, normalColumns []string) (string, error) {
	// Extract single tables from the UPDATE table references.
	singleTables := extractSingleTablesFromTableExprs(originalDatabase, stmt.Tables)

	// Find the table matching the original table.
	var matchedTable *TableReference
	for _, table := range singleTables {
		if strings.EqualFold(table.Table, originalTable) {
			matchedTable = table
			break
		}
	}

	// Extract update column names that belong to the original table.
	updateColumns := extractUpdateColumns(stmt.SetList, originalDatabase, originalTable, matchedTable, normalColumns)

	has, err := hasDisjointUniqueKey(ctx, rCtx, originalDatabase, originalTable, updateColumns)
	if err != nil {
		return "", err
	}
	if !has {
		return "", errors.Errorf("no disjoint unique key found for %s.%s", originalDatabase, originalTable)
	}

	var buf strings.Builder
	quotedColumnList := quoteMySQLColumns(normalColumns)
	if _, err := fmt.Fprintf(&buf, "INSERT INTO `%s`.`%s` (%s) SELECT %s FROM `%s`.`%s` ON DUPLICATE KEY UPDATE ", originalDatabase, originalTable, quotedColumnList, quotedColumnList, backupDatabase, backupTable); err != nil {
		return "", err
	}

	for i, field := range updateColumns {
		if i > 0 {
			if _, err := buf.WriteString(", "); err != nil {
				return "", err
			}
		}
		if _, err := fmt.Fprintf(&buf, "`%s` = VALUES(`%s`)", field, field); err != nil {
			return "", err
		}
	}
	if _, err := buf.WriteString(";"); err != nil {
		return "", err
	}
	return buf.String(), nil
}

func quoteMySQLColumns(columns []string) string {
	var quotedColumns []string